Ask a Question forum: My soil changed ...

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Name: Lyn
Weaverville, California (Zone 8a)
Garden Ideas: Level 1 Garden Sages Celebrating Gardening: 2015
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RoseBlush1
May 8, 2017 8:25 AM CST
When I first started planting my rose garden back in 2005, I was told to dig BIG holes and perk test them because I was gardening in lousy soil. It would take me two days to dig ONE rose hole about three feet deep. The soil was dense with small rocks ... none larger than the size of my fist. I had to pry them apart as I got deeper into the hole.

There was no way I could have prepared a whole bed. Nor could I have built raised beds. I live in the mountains and would have had to import soil from the Valley which would have been incredibly expensive.

When I perk tested the holes, I was happy if they drained over night. I also learned the hard way not to include any compost in the back fill for the base of the hole .. it decomposes and the roses sank ... oops !

Over the years, I have been watering and mulching, but not digging in organic materials. Everything was put on top of the beds.

Sunday, I dug out a rose to pass along to a friend and dug another big and deep rose hole. The digging was surprisingly easy. There were few rocks. Huh ? Oh, well. I kept digging. When I had my big, deep hole, I perk tested it. It drained in an hour. That's too fast ! It means the soil is not holding moisture as well as it used to.

We get temps in the high 90s to low 100s for most of the summer. I like to water deeply once a week because it helps make the plants more drought resistant. If the soil isn't holding moisture, that's a bit of a problem.

I discovered I cannot buy soil that is not almost pure compost up here. I need some suggestions as what to use for my back fill to slow the drainage.

This is for the bottom half of the hole. As I move up, I'll add more compost to the back fill because that is where the feeder roots of the rose are located.

Suggestions are welcome and needed.

Thank you in advance.



I'd rather weed than dust ... the weeds stay gone longer.
Name: Steve
Prescott, AZ (Zone 7b)
Region: Southwest Gardening Roses Irises Lilies
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Steve812
May 9, 2017 10:25 AM CST
Lyn,
I have heard the saying 'dig a $20 hole for a $5 tree,' but I've never talked to someone who took the advice so quite so seriously. I'll try to take the question as seriously as you do. I'm agog at your dedication to executing the planting phase perfectly. There's a huge amount that I don't know, so my answer will be correspondingly lengthy.

You identify a number of issues, and for each issue there are a number of alternatives. What do I see as the issues?
1) What rose do you intend to plant here?
2) What is the right amount of organic material to have in the soil? And what purposes does it serve?
3) How does one build soil that allows moisture to permeate quickly, then holds and releases moisture as it's needed?
4) What are the drawbacks of having a mature, well developed rose sink a few inches into the soil?
5) Are there specific construction practices that allow one to get everything that is required?

Issue 1: If you were intending to plant a rugosa rose here, I think loose, well draining soil might be just fine. The right ammendments would improve things, but perhaps not much would have to be done to be successful (assuming frequent irrigation...) There are a few other species roses that do well in sandy soil, too. Spinosissima hybrids such as Stanwell Perpetual come to mind. It is possible that if one planted one such rose without amending the soil one would have increas watering frequency until the rose reached a certain critical size, say waist high.

If you are intending to plant a hybrid tea rose on its own roots, you are going to be dealing with a rose that already needs a huge amount of coddling and I would guess that a custom blend might be called for. What is needed is light, friable soil with lots of air passages, so that roots easily penetrate it but soil which also does an excellent job of holding moisture. One additional goal is to get a blend of local soil and whatever mix is going into the hole in order to encourage root growth beyond the initial hole.

If the rose were grafted to a rootstock such as Dr Huey then having light, friable soil is not such a high priority, rather, getting it to hold moisture might be a more important one. Dr Huey seems to manage pretty well in reasonably heavy soils.

In any case, you are right that with air temperatures in the 100s keeping roses well hydrated is a monumental task. Water evaporates from saturated (damp) surfaces into dryish air in proportion to vapor pressure. The chart below shows vapor pressure of water as a function of temperature.
59 F - 1.7 -- baseline 1.0
68 F - 2.3 -- 1.4 times as fast
86 F - 4.2. -- 2.4 times as fast
95 F - 5.6 -- 3.3 times as fast
104F - 7.3 -- 4.3 times as fast

When the air temperature is 104 F a rose potentially loses water 4.3 times as fast as if the air temperature were 59F. When temperatures go above the nineties special measures need to be taken. When they go into the hundreds those same efforts need to be redoubled. Maybe this would be a difficult climate for any rugosa rose to grow in.

Issue 2: There are lots of reasons one adds organic material to soil. One is mechanical. Organic material loosens heavy clay soil making it easier for roots to grow. It also helps aerate soil. One might imagine that most plants breathe through their roots, so poor air circulation can kill them. Loosening the soil with sand, vermiculite, and organic materials helps them breathe. A third reason to add organic material is that it retains moisture. In the case of loose, sandy soil water permeates easily, but it flows through quickly without being absorbed. It is then unavailable to the rose when the rose needs it. Organic material grabs the excess water from wet soil, holds it, and it releases it as the soil dries out. (There are engineered materials, special polymers that are especially good at this and some are incorporated into potting soil media. Electronics and pharmaceutical mfg companies use a really fine powder of silicon dioxide in little paper sacks to absorb water vapor. Silicon dioxide is, interestingly, is the chemical composition of sand. It works because the particles are almost nanoscopically tiny.) Finally, organic materials feed the soil biota which feed the rose. Almost by definition, soils low in organic materials are low in fertility.

Issue 3: The physical, chemical, and biological qualities of the soil all matter because they interact with each other and with the rose. Perfect soil has a set of properties that are built up from a number of very different qualities. At the basic level, a plant needs soil with the mechanical strength to hold it vertically. Usually this is not an issue - but it would be possible to engineer a very light, fluffy soil that fails this criterion. Most of the ammendments we add make soil lighter and fluffier. Soil needs to be permeable to water and air. Air and water need to be able to penetrate the surface and move through it freely in order that they reach the roots. Heavy clay soils are poor at this. Sandy soils are good at this. Soil needs to absorb, retain, and release moisture. Clay soils are good at this. Sandy soils are poor. Organic materials tend to be good at allowing air, water and roots to move through easily and they are good at water retention. For this reason they are the first item added to poor soils. When soils are very sandy, one can add some clay. But if the soil has too much clay one may add vermiculite instead. It absorbs and releases moisture as does clay, but it is more permeable to water and air. It behaves much like organic materials in a physical sense, but not in a biological sense.

Issue 4: If we imagine that the hole is three feet deep and one fills the hole with nothing but organic material and the rose, and if we imagine that the organic material all burns off in one year then the rose will sink a full three feet in one year. Clearly this is not a good solution. On the other hand, if the rose were to sink, say 6 inches in a few years and it were a rose that normally grew to head height, we might not notice or care. In fact, in all the places I have gardened I have purposefully made a 2 inch deep basin, 2 feet across at the base of a rose so that I can hand-water the rose quickly and have all the water stay where it is needed most. One of the questions to ask is 'what is the relationship between organic content of soil and its rate of sinking?' One might start out imagining that it's proportional. But it's not. Grains of sand and clay can be built up in such a way that void-space is huge, else the 20 ft tall anthills of Africa could not exist. My SWAG is that soil with less that about 30% void space does not settle very much in garden settings. (It's very different for building purposes.)

Issue 4: So as we approach the problem with these ideas in mind, we consider our design goals. We want to make the soil loose, open-pored and well aerated. We want it to absorb and release water effectively. We want it to host soil microorganisms effectively. We want it to maintain its dimensional integrity. We want to incorporate local soils in the hole. What are our available materials? We have local soil which, evidently, is open, loose, a bit sandy, a bit poor at moisture retention, and low in organic materials. We can consider adding compost, coir, rotted manure, (sand, but it's not necessary here), clay from kitty litter, vermiculite, nutritional supplements such as greensand, bonemeal, gypsum, epsom salts (all in tiny quantities, of course), other stuff.

Issue 5: Apart from what I have seen of roses budded to Dr. Huey rootstock, I happen not to have a good visual model of the shape of the root system of a rose growing in the ground. There are particular geometric reasons that would suggest that this conical shape is a pretty good starting shape for root systems, so I will assume that the overall shape develops from this cone shaped skeleton.

If we believe that it is important not to let the plant sink very much, then the first step might be to start with four parts local soil and add a fifth part composed of good compost, coir, clay, and vermiculite. From this we would build a conical mound in the hole that is roughly 2 ft high. If sinking is of paramount importance, then one might use more vermiculite and coir and reduce the amount of compost. If nurturing soil biota is more important, than more compost would be in the mix. Obviously, the idea of using more compost near the top of the mound is a good one, even if not that practical. Including a few pints of clay in the mix is probably an excellent idea for many reasons. Actually, if you could get the vermiculite level to 10% you could have a really good level of moisture retention without compromising structure or porousity of the soil.

At this point, I must say that there is a piece of information I don't know about, and that is about the differentiation of function in roots. If one were to assume that all roots take up materials (moisture and nutrients) from the soil in roughly the same way then it would be logical to advocate mixing the balance of the fill material uniformly with just less than 1/3 compost and 2/3 local soil, with the balance of the mix being soil ammendments: coir, clay and vermiculite. But you indicate that rose roots are differentiated to match the way soils are built by natural processes. Water might be found deep in the soil but most of the things that bring fertility to soil are found in the top six or twelve inches. Rose roots have adapted to this. In light of this we would vary the amount of bioactive material (compost) in the soil. In the lower levels of the fill one would concentrate coir, clay, and vermiculite for water retention. In the top six inches one might construct the fill from 60 or 70 percent compost. After all, you'll want to mulch the rose from time to time and this will help determine when and how much compost/mulch to use.

One question that arises from this description is "How do we know how much clay to add?" I don't know the answer, but I have been told that bricks are held together with just 10% clay. So creating soil mixes with much more than this can increase the risk that the soil closes up and loses its aeration. Obviously, if there are lots of earthworms and ants working in the soil, one could increase the clay content because these creatures work diligently to open up the structure of the soil. I'd hesitate to go much above 15%. Instead I'd use coir and/or vermiculite.

"You mentioned coir, why?" One of the problems alluded to was that organic materials 'burn off' they are decomposed by soil biota. This is good in that it increases soil fertility. It is bad, too, because once organic materials are gone the soil tends to lose aeration and with it the ability to absorb and release moisture. Coir is an organic material that tends to break down slowly, it lasts maybe five or ten times as long as compost. This means that it can aerate soil and retain moisture for a correspondingly longer time period. It would also lead to less slumping of soil. So one might use coir in the construction of the mound and near its base. Of course, to achieve some permanent level of aeration one might use vermiculite. It, too, can absorb up to 4 times its weight in water and as an inorganic material it's not going anywhere fast.

Of course, there are probably thousands of permutations to this rough outline, each one being better than some others for a particular location. It's impossible to know what's best without knowing a lot more about the physical and chemical composition of the soil, the specific roots of the rose, and about how these interact (including a huge amount of stuff that we simply do not know); but I think it's possible to know what kinds of things might improve the situation in any location and why.

"Isn't this a lot of work to do just to plant a rose?" There's no better time to get the planting hole right than before the rose is planted in it. I have heard of people who cannot afford to live in a house spending $1000 on special deer-hunting fatigues. Who's to say?

I hope this explanation all makes sense.
When you dance with nature, try not to step on her toes.
Minnesota (Zone 3b)
RpR
May 9, 2017 11:14 AM CST
If you are digging a three by three foot hole, filling it with water and it drains out in an hour, why is that bad?
A matter of minutes I can understand.

Now obviously my subsoil is different from yours but I can dig a three by three foot hole, in black gumbo with yellow clay below it and it will be drained within thirty minutes, without exception.
If the soil the roses are planted in is, and I have no idea what soil is available around there, some where between sand-clay and loam , brought in soil, not natural, then I do not see why you are worried.

I was at a Nursery yesterday where the owner had brought in 8,000 yards of top soil for there gardens, rocky and too much like sand is natural there.
They said decent top soil was getting hard to find so I told them that the gumbo down by my home town would be good for his area but he said that was to claylike yet, as I said, my holes drain in a lot less than an hour.
Is it only that hole or all holes now drain more quickly?

I dug two large holes five feet by four feet for several trees approx. five years ago on a landscape project.
One I could fill half way with water and it would be gone in less than one half-hour, I saw that at the bottom I had pierced the clay fill they brought in for the house and the water was running out down to the slough that surrounded the house in the natural soil.
The other held water for over an hour as I could not get below the clay fill without digging a hole large enough a man could stand in and maneuver a shovel; my boss said not to worry.
Well the cheap tree in hole one flourished, the expensive tree in hole two went belly up, it drowned.

Your hole may have pierced what ever layers of soil you have and is simply draining naturally,
Now I am shooting in the dark here as your drainage rate does not seem bad, from rates up here.
The soil up in the North garden before I heavily amended, including bring dirt from the South garden, if I poured a two gallon bucket into a two by two hole, it would empty in less than five minutes, which is why I am perplexed that you think your rate is too quick.
We had summers up here ten years ago where corn fields had the blue-grey color of death by the end of June due to heat and no rain, so I am aware of what low one hundred and high nineties can do to a garden in sandy soil.

One thing that has done well in my roses, to a degree, I started putting Cocoa Bean Hulls over the entire garden two or more inches deep.
Under the surface which can appear dry, the bean hulls kept the soil moist plus the hulls have a natural low fertilizing quality.
I have noticed though that down South, some of the newer holes where when I planted a new or replacement, working the old hulls into the ground, and covering with new, some of those holes drain at a goodly higher rate than those with natural garden soil or even bagged bucks-up soil I bought. Where as a standard hole will have temp. running off surface water with at most a couple of gallons, these take approx. twice as much before the water is running off.
Great as far as tipping in fall goes, but in the summer, though not probably necessary, I give them an extra bucket of water on occasion just to make me feel better.
I do not in spring when I stand them up, tamp them down like one would a newly planted rose as that makes tipping in fall harder, so my holes probably have more airspace than normal but it does not seem to harm them.
[Last edited by RpR - May 9, 2017 11:30 AM (+)]
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Name: Steve
Prescott, AZ (Zone 7b)
Region: Southwest Gardening Roses Irises Lilies
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Steve812
May 9, 2017 3:27 PM CST
As you pointed out, high temperatures and low humidity can play havoc with plants growing in sandy soil. I think California can experience 100F temps that can routinely last for weeks or months on end without precipitation and therefore the local practices may reasonably be a little more conservative with regard to clay content in soil than the standard for Minnesota where 100F days and three months of summer without a drop of rain are both regarded as unusual events. As you suggest, it may be that climate change will require more aggressive soil moisture conservation in MN and much of the plains states area.

As far as drainage goes, Lyn lives up the side of a mountain. Retaining soil is more of an issue, I think, than keeping it drained.

I've heard great things about cocoa bean hulls. I'm lucky to have a supplier of other organic mulch material.
When you dance with nature, try not to step on her toes.
Name: Lyn
Weaverville, California (Zone 8a)
Garden Ideas: Level 1 Garden Sages Celebrating Gardening: 2015
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RoseBlush1
May 9, 2017 11:52 PM CST
Thank you Steve and Rpr for responding.

I read both of your posts earlier in the day when I was taking a break and have been thinking about what you wrote. I've also been observing what is happening in other parts of the garden. I am seeing water stress throughout the garden, so the soil change I found when I perk tested this rose hole was kind of a blessing. I am going to have to change how I mulch and how I water going forward.

We may be talking about roses, but this question is really more about soil than about roses. My understanding about how to grow good roses is much better than my understanding about soil dynamics. I have a lot to learn there ... Smiling

First let me address Rpr's question about why a fast draining planting hole will not work in this garden. In my mountain climate there is a 40 to 50 degree temperature change between day temps and night temps. During the day, the plants lose a lot of moisture through their leaves through transpiration. With the cooler night temps, if there is moisture in the soil, the plants have the opportunity to fully rehydrate before the next day's high temps hit. Without that moisture, I would have to supply supplemental water in the morning for them to survive.

My property is located on a watershed for the Trinity River. Drainage is not a problem. In the past, the soil held enough moisture that I did not have to deep water more than once a week even when the daily temps were near or over 100F for months at a time. I did an additional feeder root watering mid-week and that was sufficient to grow healthy roses.

My soil has changed sufficiently so that in the last couple of weeks with day temps only hitting the 80s for maybe three days, the roses are showing water stress. That's a problem.

Steve ... You have provided a lot of food for thought. I can address the rose issues because I understand the botany of the plant, but the information you have provided about soil is going to take some time to digest.

Yes, I do believe in investing time in preparing a good planting hole, but I don't follow the directions commonly found in rose literature. As I mentioned before, I found out the hard way that I needed to tweak my planting method to work in this garden so that my roses don't sink too much. But more importantly, when reading about how to prepare a planting hole the basic premise is that you are planting in ideal soil ... that rich loamy soil that roses are said to prefer. I am not planting in that kind of soil, so I have to take into consideration the make up of the native soil, too ... Smiling Also, most of those planting instructions ignore the botany of the plant, so often the instructions are misleading.

The goal of a good planting hole is to set the plant up to be a healthy plant that you don't have to coddle. I'd rather put the labor in up front and be a lazy gardener down the road ... Smiling

1) What rose do you intend to plant here?

Actually, it really doesn't matter as much as people think. That's not to say that all roses will thrive in all soils and all climates, but they are not as particular as rose literature leads us to think they are. Roses are brambles. They have the root structure of a bramble. Yes, they vary by class, but overall, it is pretty safe to generalize about the root structure.

The plants have deep roots which anchor the plant and draw on reserve supplies of moisture deep in the soil that is beyond the reach of the feeder roots. The feeder roots are located near the surface of the soil and are always pushing forward and branching out.

2) What is the right amount of organic material to have in the soil? And what purposes does it serve?

It is a myth that you have to "food" for the anchor roots. They are fed by the feeder roots near the soil's surface. If you think about it, Nature deposits all organic materials and manures that plants use for nutrients on the surface of the soil. It is not buried.

The organic material only needs to be added to the top few inches of the planting hole and replenished as needed.

The question then becomes how to build a planting hole that breathes, drains well and does not become compacted over time.

Yes, my soil is low in fertility. I started out with subsoil. The house pad was cut out of a slope. Even tho' I have added a lot of organic material over the years, it has decomposed and I have a very thin layer of top soil. The heat eats mulch so that I am always having to add more during the growing season.

3) How does one build soil that allows moisture to permeate quickly, then holds and releases moisture as it's needed?

You lost me here. Sorry.

4) What are the drawbacks of having a mature, well developed rose sink a few inches into the soil?

In my garden, it is a problem because I have a very thin layer of top soil which I have to cover with mulch. The feeder roots extend far beyond the canopy of a rose, so if the rose has sunk, it is more difficult for them to reach the surface of the soil.

5) Are there specific construction practices that allow one to get everything that is required?

I've read this section several times and find myself wondering if there is any way we can test it.

I can pot the two roses I wanted to get into the ground into large containers and allow them to grow a root mass over the summer and plant them out in fall. My soil doesn't freeze, so that would give me time to test the mix you have suggested.

What do you think ?

I'd rather weed than dust ... the weeds stay gone longer.
Name: Arturo Tarak
Bariloche, Rio Negro, Argentin (Zone 8a)
hampartsum
May 10, 2017 4:13 AM CST
I've been wondering about these issues for quite sometime already. I also live in a mountain type environment. However I never hit 100ยบF! (Maximum 86ยบF for a very short while). Winters are mild cold (minimum 23ยบF). But because of elevation (Ave 2779ft asl) our soils do not seem to build up enough warmth to keep up with the expected garden growth rate found in the more continental northern hemisphere. Yet I do eventually have fully grown rosebushes living beyond 30 yrs old. What I sense that each of us has to move away from standardized practice. Gardening has reached rightly so to its heights initially in Europe, specially England, Germany, Holland and France. Their gardening options are quite simmilar in those places. Most of where gardeners operate are at close to sea level locations and with relatively well spread out rains during the seasons. Northern gardeners have to deal with cold hardiness. Having said this, one can reason out why cultivars are so well adapted to those conditions.
Once one moves away from that type of locations then each of us will have to find a compromise from what traditional literature suggests and with what can achieve in one's own place. This type of adjusting is the challenge that awaits all of us in view of visible climatic change as well. Climatic change will not produce the same effect everywhere. On the contrary it will be very site specific.
I have a strange natural soil where my rosebushes are growing. Acidic, sandy . No drainage problems,very poor in nutrients with exception of phosphorus ( because of high volcanic ash content), but low in N and K. Almost no Ca or Mg. These have to be added either with compost or chemical fertilizing. By adding compost I improve aereation, also areation improves soil warming in spring. This part is critical because the rosebush gets enough daytime light stimulus but the roots down there are not yet ready to do their part. So I do have trouble to get the roses off onto a good start early spring.
I'm not too sure whether the size of the root ball should extend beyond the crown width. Plants in general tend to grow their roots as wide as necessary but not beyond. So if the plant has enough available nutrients within the radius of its crown, then it wouldn't be very important to have huge holes dug. In many ways what I'm imagining is the concept of a sunk in "container" hole where the conditions within the hole are closer to that required by the rosebush. Perhaps one other way of reducing excesive loss of moisture is by lining the hole with some fabric ( the green one used to prevent weeds from growing with necessary holes driven through to avoid drowning the plant). Adding clay into the hole is my other alternative. I have recently found a fantastic deposit of clay under my dried up lowland pasture. Geologically it was a pond that silted up and finally reverted into a wet meadow. Sedges and reeds still dot the place. I never was successful in growing roses in that part of the farm. This year I added some clay on the top of my rosebeds along with my regular compost mulch and horsemanure. My soil harbors earthworms in normal quantities. I do expect that they'll do the work of sending nutrients downwards...
Organic matter when it decomposes binds itself with the inorganic particles creating something new, that is partly organic and partly inorganic. What we know as good loamy garden soil ( that roses and almost every garden plant loves) is as far as I found out almost always a human construct. That soil almost never exists in nature. So how each of us will achieve it is the local challenge. Because it is a human construct, human factors have to be taken into consideration: i.e how much work can each of us provide, both in the ammount of physical effort as well in the ammount of time available including the schedulling adjusted to seasonality.
Normally one can't afford to spend in almost continuous soil testing hole by hole or even within the scope of a bed. So we are forced to improve our observational skills and eyeball trial and error procedures in search of reliable results. The empirical way vs. the scientifc way. If one is at ease with the empirical way, then perhaps after a decade one can identify enough site specific data that will support the adequate gardening procedures... Hilarious!
[Last edited by hampartsum - May 10, 2017 5:12 AM (+)]
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Name: Rick Corey
Everett WA 98204 (Zone 8a)
Sunset Zone 5. Koppen Csb. Eco 2f
Frugal Gardener Garden Procrastinator I helped beta test the first seed swap Plant and/or Seed Trader Seed Starter Region: Pacific Northwest
Photo Contest Winner: 2014 Avid Green Pages Reviewer Garden Ideas: Master Level Garden Sages I was one of the first 300 contributors to the plant database! I helped plan and beta test the plant database.
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RickCorey
May 12, 2017 5:39 PM CST
I usually think of peat and compost as the basic things to add, to increase water-holding capacity. Maybe finely shredded, almost fibrous bark.

I've read about expanded clay/shale products like Turface that are like Perlite, except porous like a sponge so they suck water into their interior, and then release it as surrounding soil dries.

I have one bed that I unintentionally made into a VERY water-retaining "container". It is not LIKE your soil at all. That bed is shallow, narrow, and over clay that is FULL of heather and Rhododendron roots.

Thumb of 2017-05-12/RickCorey/732fb8

I wanted to keep the roots out of my very shallow bed, and also didn't want it to dry out instantly as water diffused through the 3/4" concrete pavers and evaporated as if the walls were wicks. So, duhh, I lined the bottom and sides with heavy plastic bags (from bags of bark). There are gaps so water can escape, but effectively no wicking.

Now it holds water forever. Water goes in but does come out, except by evaporating from leaves. Eventually it might salt up! But I'll rework it before that.

Well, if your water level just dropped like a rock, and your rocky subsoil wicks water away like a 50 foot dangling piece of toweling, maybe radical actions like partially lining any planting hole that you re-dig with some pieces of plastic. Maybe small pieces so you don;t wind up trying to grow a rose in a "pot with no holes".

That might be a TERRIBLE idea. I don't know.

But perhaps the only reason your rocks did NOT act like wicks in the past was that they were so devoid of soil that they just acted like a bag of rocks: NO wicking in the past. The change from your root zone to the rocks was so abrupt back then that most of the water you gave them became "perched" water right where your roots wnated it to stay. Now it obeys gravity AND capillary forces, so that there is a 50-foot or 100-foot WICK leading from your root balls down to the water level, wherever THAT is in such a fast-draining matrix.

This is just speculation.


Now you've improved your soil and bits of solids and organics have been washing down into the gaps between your rocks, stones and gravel. maybe now those air channels have become wicks.

Name: Lyn
Weaverville, California (Zone 8a)
Garden Ideas: Level 1 Garden Sages Celebrating Gardening: 2015
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RoseBlush1
May 12, 2017 9:58 PM CST
Rick ... Thank you for taking the time to reply to my question.

The change from your root zone to the rocks was so abrupt back then that most of the water you gave them became "perched" water right where your roots wnated it to stay. Now it obeys gravity AND capillary forces, so that there is a 50-foot or 100-foot WICK leading from your root balls down to the water level, wherever THAT is in such a fast-draining matrix.

The interesting thing that I found when I dug this hole is that my rocky soil is no longer rocky soil ... Smiling The structure of the soil has changed completely over the years. All I have done was add organic material to the surface and water. Yes, I fed the rose, but not with enough chemicals to change soil structure.

I am guessing it was the humic acid, which is a by-product of decomposing organic material, and water passing through the rocky soil that caused the change by eroding the rocks.

The reason the rose I had planted there failed is because with my old watering practices, the water passed through the root zone too fast for the plant to take up the moisture it needed to thrive. The soil was probably dryer than the roots at times and stole moisture from the roots through osmosis.

I am glad you mentioned the perched water table effect because that is the technique I am going to use for this rose hole. I t-mailed Sue to see if she had any ideas and she suggested that I experiment using this method to hold moisture at the surface of the rose hole where the feeder roots of a rose plant are located. I think it's a brilliant idea and if it works, plan to implement it throughout the garden.

The base of the rose hole will be back filled with native soil and some more rocks to vary the particle size to create a less uniform soil mass so that there are no transition issues, then I will build the perched water table and in the top few inches place the good soil with the stuff that worms and soil bacteria love for the feeder roots. I'll cover all of it with mulch to protect those fragile roots from the heat.

Hummm ... just wondering ... maybe your narrow bed is experiencing the "perched" effect ... Smiling


I'd rather weed than dust ... the weeds stay gone longer.
Name: Rick Corey
Everett WA 98204 (Zone 8a)
Sunset Zone 5. Koppen Csb. Eco 2f
Frugal Gardener Garden Procrastinator I helped beta test the first seed swap Plant and/or Seed Trader Seed Starter Region: Pacific Northwest
Photo Contest Winner: 2014 Avid Green Pages Reviewer Garden Ideas: Master Level Garden Sages I was one of the first 300 contributors to the plant database! I helped plan and beta test the plant database.
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RickCorey
May 15, 2017 7:22 PM CST
Not just perched ... the plastic has so few holes for drainage that it's more like a long, skinny container with only a few holes.

I made "new soil" for that bed instead of modifying the "soil" already there (really, "the mass of roots that were already there"). That soil is very organic by my yard's standard. When I watered that bed like I did everything else, it started to become a "bog bed". So I started giving it 1/3rd or 1/4 of the water, and it became pretty happy, for a bed only a few inches deep!

Good luck with deliberately making "perched root zones"! Great idea.

It's awesome to me that you went from "rocks and packed gravel" to "real soil". It really can be done! I wonder if somehow frost heaves can sometimes push rocks out of soil sideways instead of forcing them to the surface?

Name: Baja
Baja California (Zone 11b)
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Baja_Costero
May 15, 2017 7:57 PM CST
Late to the conversation here, but I have enjoyed reading everyone's responses. Here is my own. Our soil is ancestral riverbed, that is to say mostly sand and rocks (generally below the size of your fist), with a 2-3 foot layer of "topsoil" (our arid Mediterranean type climate yields rocky soil) that's visibly browner and probably has some organic matter in it, but is still mostly sand and rocks.

The issue I have faced is the necessity of adding organic matter to make the place more habitable for the succulents I like to grow. They don't root very deep so what I usually do is dig a hole about 2 feet deep and backfill with a mix of 50/50 native soil and amendments (compost, pumice, coir, some osmocote for good luck). This has worked pretty well. I think using a mixture helps the plant root outward and creates more of a bridge with the native soil.

As that compost breaks down, the level of the soil in the filled hole will drop. For this reason I always seat the plant a few inches above the surrounding area, with a ring of rocks (never in short supply) to keep the mound together for a year or two. It's a crude solution but by refilling a raised area, you avoid the cratering effect later on.

I would like to add to the chorus about coir being a really useful additive for moisture retention, with a long lifespan and less of an ecological footprint than peat. Whenever I add coir to anything, I add an equal amount of pumice (my potted plants live in 50% pumice). That's probably more of a useful thing for succulents than roses, but it's probably a good idea to use coir in measured doses because it is tremendous at slurping up water.
[Last edited by Baja_Costero - May 15, 2017 7:58 PM (+)]
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Name: Lyn
Weaverville, California (Zone 8a)
Garden Ideas: Level 1 Garden Sages Celebrating Gardening: 2015
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RoseBlush1
May 15, 2017 9:26 PM CST
Rick ... The roses are in the ground with the perched root zone. It is an experiment. I am reluctant to call it a solution, yet. I won't know until next year. Planting a rose is like planting a young tree. You water it more often until it is established as the root system is inefficient. The real test is when you back off from that kind of watering schedule.

My new problem is since I recognized how my soil changed when I dug these rose holes, I saw that the drainage has changed throughout the whole garden. I've got a huge problem in that I have to find a way to slow down the drainage or I will be a garden slave. It's possible that coir is the answer, but I won't have time to research that until next week when the temps jump to the 90s and I am caged inside because I can't work in that kind of heat.

Right now, temps are in the 60s and I am in crisis mode ... Sighing! The person who was supposed to deliver my mulch materials three weeks ago isn't going to come through. So now, I have to get the whole garden mulched before the heat hits. YIKES !

I am doing something I have never done before. I am putting mulch material (straw) on top of weeds so that I have something to cover the bare ground. After I get the whole garden mulched, I'll pull the mulch back in sections and weed and put the mulch back. The important thing is to have mulch down to hold moisture in the top layer of soil. Since I hand weed, that is quite labor intensive.

BC ... the cratering was due to a novice mistake. D'Oh! I am still fixing the problems I created by not anticipating the impact of the decomposition of the organic material I added to my back fill when I first planted my roses. I still need to lift several more roses, but not until next spring.

I have a no-till garden because the rose roots are very close to the surface of the soil and I don't mess with the rose roots .... Smiling I know I have to keep the soil moist around those roots at all times because if the soil is dryer than the roots, the soil will steal moisture from the roots through osmosis.

Next week, I'll have to start researching how to maintain the required moisture without tilling anything into the soil.

It's always something ... Smiling
I'd rather weed than dust ... the weeds stay gone longer.
Name: Arturo Tarak
Bariloche, Rio Negro, Argentin (Zone 8a)
hampartsum
May 16, 2017 2:23 AM CST
Lyn, I'm sorry to hear that your soil provider backed out! Sighing! I've got no idea of how the cost of coir there. My local alternative is shoddy. Shoddy is a byproduct of shearing sheep wool. Its the natural wool that comes normally mixed with hair in the hindquarter legs and bellies that are harvested when the shearing crew steps in. Its almost worthless. It can be used unwashed to line up a ground hole and will hold moisture as much as coir. Fully organic. In the ground it has a similar life span. I read for coir 2-5 yrs. In my local temps thats what it takes for shoddy to decompose.
However in terms of improving moisture retention, I still consider that you might have to think about mixing in some type of clay plus lining up the rose hole. Its imagining your roses in some type of limited sunk "containerized" holes. Then perhaps a drip system might start working effectively...with considerable less work in keeping the rose hole moist.
Name: Lyn
Weaverville, California (Zone 8a)
Garden Ideas: Level 1 Garden Sages Celebrating Gardening: 2015
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RoseBlush1
May 16, 2017 8:46 AM CST
Thank you, Arturo ...

The rose holes are done. It's the rest of the garden that is now the problem. I'll have to work on the "real" solution next week. For now, I have to get the bare ground covered.

All suggestions are welcome.
I'd rather weed than dust ... the weeds stay gone longer.
Name: Tiffany purpleinopp
Opp, AL ๐ŸŒต๐ŸŒทโš˜๐ŸŒน๐ŸŒป (Zone 8b)
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purpleinopp
May 19, 2017 5:04 PM CST
Keep adding organic material to the surface. The ground where I am is about 95% sand, so it's impossible to keep the ground moist for more than a few hours without a cover of constantly renewed organic matter. Over time, the soil changes to rich, dark, loose, fertile "garden soil" that stays moist, but is never soggy, that plants grow like crazy in. I don't use anything purchased from a store, but don't let any organic matter leave our property, except bones. Kitchen scraps, yard waste, shredded paper from work, sawdust, pine needles, leaves, whatever presents itself is used.

What started, for me, as merely smothering grass to have a flower bed has turned into an interest for microbiology that I would have never suspected I would have. Not in and of itself, but because my plants, any plants, can only be as good as their roots, which can only be as good as the soil in which they are growing. ... so I want to have good soil, not just any old dirt.

15 mins that was life changing for me:
https://permaculturenews.org/2...

๐Ÿ‘€๐Ÿ˜๐Ÿ˜‚ - SMILE! -โ˜บ๐Ÿ˜Žโ˜ปโ˜ฎ๐Ÿ‘ŒโœŒโˆžโ˜ฏ๐Ÿฃ๐Ÿฆ๐Ÿ”๐Ÿ๐Ÿฏ๐Ÿพ
The less I interfere, the more balance mother nature provides.
๐Ÿ‘’๐ŸŽ„๐Ÿ‘ฃ๐Ÿก๐Ÿƒ๐Ÿ‚๐ŸŒพ๐ŸŒฟ๐Ÿโฆโง ๐Ÿƒ๐Ÿ๐Ÿ‚๐ŸŒพ๐ŸŒป๐ŸŒธ๐ŸŒผ๐ŸŒน๐ŸŒฝโ€โ˜€๐ŸŒบ
โ˜•๐Ÿ‘“ The only way to succeed is to try.
Name: Lyn
Weaverville, California (Zone 8a)
Garden Ideas: Level 1 Garden Sages Celebrating Gardening: 2015
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RoseBlush1
May 19, 2017 8:39 PM CST
Tiffany ...

That's pretty much what I have done over the years. I started with subsoil. The soil was totally dead. It was dense compacted rocks with clay between them. There were no worms. No weeds. Just rocky "stuff". The house pad was cut out of a slope and is about two to three feet down from the natural top of where the slope would have been. There was no organic material in the subsoil.

I hauled in organic material every spring and fall.

It has been changing over time, but I would not say it is rich, fertile soil yet. However, the quality of my weeds is much better than they were in the early years ... Whistling

When I dug this rose hole, there were no dense rocks and lots of worms and such. AND the soil drains too fast ... Smiling

I'll make it work. The plants in the garden do have good root systems.
I'd rather weed than dust ... the weeds stay gone longer.
Name: Tiffany purpleinopp
Opp, AL ๐ŸŒต๐ŸŒทโš˜๐ŸŒน๐ŸŒป (Zone 8b)
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purpleinopp
May 20, 2017 7:35 AM CST
That all sounds great. It's hard to pick'n'choose the organic matter one has available, but I'm always the most excited about the greens, the "juicy" stuff because of the dryness of my soil. There are some weeds I let grow to blooming size just to have their mass of greenery for composting. And I try to solicit OM from others when possible. "I'll take the rinds home from this watermelon" and things like that. After a while, people get trained and offer things. I get frustrated too because it's all happening so much more slowly than it would if I had access to unlimited quantities of OM's.
๐Ÿ‘€๐Ÿ˜๐Ÿ˜‚ - SMILE! -โ˜บ๐Ÿ˜Žโ˜ปโ˜ฎ๐Ÿ‘ŒโœŒโˆžโ˜ฏ๐Ÿฃ๐Ÿฆ๐Ÿ”๐Ÿ๐Ÿฏ๐Ÿพ
The less I interfere, the more balance mother nature provides.
๐Ÿ‘’๐ŸŽ„๐Ÿ‘ฃ๐Ÿก๐Ÿƒ๐Ÿ‚๐ŸŒพ๐ŸŒฟ๐Ÿโฆโง ๐Ÿƒ๐Ÿ๐Ÿ‚๐ŸŒพ๐ŸŒป๐ŸŒธ๐ŸŒผ๐ŸŒน๐ŸŒฝโ€โ˜€๐ŸŒบ
โ˜•๐Ÿ‘“ The only way to succeed is to try.
Name: Lyn
Weaverville, California (Zone 8a)
Garden Ideas: Level 1 Garden Sages Celebrating Gardening: 2015
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RoseBlush1
May 20, 2017 7:47 AM CST
Tiffany ...

I don't know where you live, but I live in the midst of a forest in the mountains of northern California. After my first year up here, I totally stopped putting kitchen scraps in my garden. They drew every wild critter to the buffet I provided. Some of them were not the kind I wanted to meet up with ... Blinking Now, that stuff goes over the cliff and the critters can wade through the blackberries and have as much as they want ... Whistling

Most of my OM is oak leaves gathered from friend's properties, alfalfa hay dust swept out from under the pallets at the feed store, old straw from the stalls of friends that keep animals. I bag up my weeds before they go to seed and let them "cook" all summer and then put them back out after the first frost to be decomposed and for the nutrients to be leached into the soil by the winter weather.

All of the above keeps the critters from digging up my garden in their search for more food ... Smiling
I'd rather weed than dust ... the weeds stay gone longer.
Name: Tiffany purpleinopp
Opp, AL ๐ŸŒต๐ŸŒทโš˜๐ŸŒน๐ŸŒป (Zone 8b)
Houseplants Organic Gardener Composter Region: Gulf Coast Miniature Gardening Native Plants and Wildflowers
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purpleinopp
May 20, 2017 9:14 AM CST
I let stuff that might attract critters brew in a bucket with water until undesirable, then turn the bucket upside-down somewhere (a diff spot each time) for a week or so. The only thing this seems to attract is some flies for the first few days after a bucket is removed, which makes popular spots for anoles & various birds to feast. Both predators are very welcome, especially when hungry. Armadillos & squirrels, and birds are critters who affect a garden (digging holes, planting seeds, sometimes eating plants &/or digging them up) here in AL. In OH, it was squirrels, chipmunks, raccoons, rabbits, birds. I've noticed no connection to any of these animals regarding the composting that I do, beyond sporadically increasing the food supply for some predators.
๐Ÿ‘€๐Ÿ˜๐Ÿ˜‚ - SMILE! -โ˜บ๐Ÿ˜Žโ˜ปโ˜ฎ๐Ÿ‘ŒโœŒโˆžโ˜ฏ๐Ÿฃ๐Ÿฆ๐Ÿ”๐Ÿ๐Ÿฏ๐Ÿพ
The less I interfere, the more balance mother nature provides.
๐Ÿ‘’๐ŸŽ„๐Ÿ‘ฃ๐Ÿก๐Ÿƒ๐Ÿ‚๐ŸŒพ๐ŸŒฟ๐Ÿโฆโง ๐Ÿƒ๐Ÿ๐Ÿ‚๐ŸŒพ๐ŸŒป๐ŸŒธ๐ŸŒผ๐ŸŒน๐ŸŒฝโ€โ˜€๐ŸŒบ
โ˜•๐Ÿ‘“ The only way to succeed is to try.
Name: Lyn
Weaverville, California (Zone 8a)
Garden Ideas: Level 1 Garden Sages Celebrating Gardening: 2015
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RoseBlush1
May 20, 2017 12:14 PM CST
Thanks for sharing ... I tip my hat to you.

I'll keep tossing things over the cliff. I no longer have skunks and the bears have stopped messin' with my fences.

I guess it depends on which critters we are talking about ... Big Grin
I'd rather weed than dust ... the weeds stay gone longer.
Name: Karen
NM (Zone 7b)
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plantmanager
May 20, 2017 12:50 PM CST
Yes, Lyn, it does depend on the critter. I stopped putting out food scraps after we were attracting bears and wild pigs. Now they pretty much stay away unless it's very dry and they come to our fountain for water.
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