What is it you need to know about holes/ rocks?

Al

I have never had soil "stream out the bottom," no need to cover the hole and there are many options for pot feet to lift a pot off a deck.
https://www.amazon.com/s?k=pot...

At least one hole depending the size of the pot. Bigger pots need bigger holes or more of them. Side or bottom makes no real difference, especially outdoors. A big rock or two that doesn't block the hole(s) to add weight is okay, but a layer all the way across the bottom makes the drainage worse.

Thank you all. Thank you ardesia for the Amazon url. I have been buying from Hope Depot. I will purchase them from Amazon. Thank you tapla, I have the informations I need from ardesia and CalPolygardener. I will make 4 holes, since my pots are big and purchase the 'feet' from Amazon. Much better than the bottles, that now go to recycling. Again, thank you all for the help.

I have used lava rock in the bottoms of some really deep pots to save on soil.

I do block holes in pots either with landscape cloth or aluminum screen.

I reuse poiing soil all the time. I either mix old in with new I'm making or add it to compost pulled. The compost ends up in putting mixes anyway.

I use reclaimed bricks under pots as pot feet. This make a really stable base as well as provides lots of refugia for lizards and other critters. Those with more formal looks might not want to see brick however.

UrbanWild: thank you, all good ideas. I am going to use reclaimed bricks, I have some of them, more stable and somewhat taller. My collection of containers is far from formal-I have been putting lava rocks on top to prevent visiting cats from digging my pots and maybe using them for their bathrooms---I have seen 4 different cats some and go. I know one is from my next door neighbor, and another one from across the street, maybe more from them....because they have more than 2 cats-owner said they are happier outdoors-I also have visiting red foxes, and lots of squirrels. And coyotes have been seen too---I would be afraid they might think a cat is a tasty meal--Landscape cloth: is that weed barrier cloth? I have lots of them. Good idea to keep the soil running out of the containers---Thanks again.

Lava rock in the bottom of pots seriously messes with drainage and should be avoided - unless we're talking about large chunks of lava that serves as ballast as opposed to a "drainage layer". Most commercial potting media based on fine particles like peat/ compost/ coir, et al, support 3-6" of 100% saturated soil at the bottom of the pot after a thorough watering. The 3 line drawings below are pots filled with soil. The shaded area of the saturated soil, aka a perched water table. Perched water is very limiting and the longer it persists in the pot, the more limiting it becomes. The drawing on the left is a conventional pot set-up with perched water at the bottom. The middle drawing shows how water perches in the soil ABOVE a "drainage layer". This takes a big bite out of the volume of healthy (well-aerated) medium available for root colonization. The drawing on the right illustrates how bricks or other large objects used as ballast will displace soil that would otherwise be filled with water. Ballast, used effectively can eliminate as much of 90% of the excess water a planting can hold, and transform the growing experience of those who for whatever reason find themselves using a medium that holds too must water to allow good root health.

Al

tantefrancine said: I have been putting lava rocks on top to prevent visiting cats from digging my pots and maybe using them for their bathrooms---

The lava rocks aren't being put in the bottom of the pot for drainage. It's on top of the potting mix to stop cats from digging in the planters and using them as their personal toilets.

I was referring to a different post - 4 posts upthread from this.
Al

I'm not sure what you mean by lava rocks seriously messing with drainage. The pots still drain well. The pots are four feet high.

Landscape fabric = weed barrier cloth.

"Drainage layers" of coarse material causes excess water, which defies gravity and remains in grow media, to "perch" (like a bird) above the drainage layer, never a good thing. Strata of saturated soil in a pot limits root function and causes the cyclic death and regeneration of the fine roots which do all of the plant's heavy lifting. When fine roots die, the plant's chemical messengers signal the plant to stop top growth until the volume of roots is sufficient to support additional top growth. Even if you don't SEE it, excess water in the pot is a pernicious robber of the plant's potential. What happens is illustrated in the image I provided above, which also illustrates the contrast between how large objects (as opposed to drainage layers) affect how much excess water a planting can have.



If a medium supports excess water between soil particles, the excess changes location from the pot bottom (when no "drainage layer" exists), to immediately above the drainage layer when one is in place. Grower's would be much better served using large objects as ballast, which displaces soil capable of holding excess water, than using a drainage layer which does not change water retention. It simply changes where the excess water is located in the pot.

Al

Although if the pots are 4 feet deep the point is mostly moot.

Well, that would depend on how deep/tall the drainage layer is, and that info wasn't mentioned. The point isn't specific or unique to 4 ft tall pots, so the point isn't moot. While a deeper pot has a higher % of soil available for root colonization unhindered by a layer of saturated soil than one shallower, the limiting effects of a layer of saturated soil are still in play for either pot.

The comment was provided as cautionary information so growers wouldn't think a drainage layer of pebbles or gravel does anything to promote better drainage in ANY pot, because in fact it makes problems associated with water-retentive media worse, no matter how deep the pot.

Al

But if the saturated layer is 6" deep and the pot is 4' deep, 3 1/2 ' is plenty deep to grow most anything.

What % of pots the average grower grows in are 4' deep? One in a thousand? One in 10 thousand? The information was to caution anyone growing in any pot that coarse layers of material like gravel/ marbles/ pebbles, ..... meant to serve as "drainage layers" are counterproductive.

Al

Urban Wild on the 28th.