Hiya Plant Community!

I have loads of plant questions for you and would appreciate any help/advice possible.

Some background:
- Location & season: NYC winter
- Plants bought from multiples sources, all around same period
- Beginning December: cat palm had spider mites, and died and was thrown out, but I treated the other plants which were collaterally infested (notably/mainly prayer plant, pencil cactus, croton mammy, pretra croton, small draceana - but all plants also got a good spray as well.) I used either [mix of castille soap + water], [mix of castille soap + water + neem oil], or [mix of water + alcohol], when I was desperate and didn't have the former ingredients.
- Months later, no spider mites on the horizon, I think.
- All plants moved around a little bit in terms of locations in the apartment, here are current approx. locations:

West Facing Windows (living room/kitchen):




East Facing Windows (bedroom):


Question in order of most struggling plants:

(1) Ti Plant:
- slowly losing leaves which go yellow/brown before dying
- repotted with pot with drainage hole
- soil often retains moisture for a while, albeit well-draining soil used
- black rot/mold (?) at leaf stem (see photos). Even when sprayed with soap mix, and wiped down, this comes back.




(2) Dieffenbacchia:
- leaves get wilty at bottom, yellow and die off
- repotted into a plastic planter with decorative outter metal pot
- soil retains moisture more than desired, albeit well-drained soil used
- plant smells like... tobacco? I thought it was the neem oil, but it's the only plant which still smells odd after weeks of not spraying neem oil mix. I looked it up and some people said their plants smell like ammonia, which could be close to tobacco? However, the soil smells fine; it is the leaves that smell like tobacco.
- similar black rot/mold (?) at stem as Ti Plant
- no apparent bugs on leaves, sometimes I find one or two black dots (1mm) here and there that could be a bug? Doesn't move though.




(3) Bird's Nest Fern:
- repotted into ceramic pot with ceramic hole
- leaves yellowing and die
- one leaf has yellow spots
- may be from product burning?
- soil drains properly



(4) Anthurium:
- Repotted into 12" plastic pot with drainage hole + decorative ceramic outter
- leaves spotted yellow, turn fully yellow, and die.
- leaves at flower dry up and die (only one flower left).
- soil stays moist a little longer than desired (?)





(5) Prayer Plant:
- original nursery pot with additional decorative ceramic outter
- spider mite infested; washed down and sprayed - no signs of mites anymore
- soil drains well
- leaves show damage & yellowing/browning at edges
- small leaves at bottom yellow and die
- may be from spray/sun damage?





(6) Rojo Congo Plant:
- repotted into 12" plastic draining pot (when bought, roots were all over top of soil)
- most of plant looks ok
- but some leaves have browning circles/eyes (?)
- and some leaves have linear holes
- leaf stems show linear "stretch marks" (?)
- soil stays moist a little longer than desired (?)





I have tons more questions, but let's start with this first million.
I can also provide more info if that helps narrow down the problems!

Thank you all so much for your input!
Looking forward to saving my plants.

Some of what I can see may be due to overwatering. Don't water until the soil has dried sufficiently (depending upon plant).

Mildew is a result of overwatering and lack of air circulation. Some plants, like the Anthurem can handle overwatering better than others but the flowers and old leaves will die. On all plants, old leaves die but they should replaced by new leaves.

If you keep your plants clean, you will have less insect problems. Spider mites especially like dust.

There is such a thing as overdoing the Neem. And, if you spray a plant with Neem while the sun is on it, it will burn.

Some of your pots seem large for the plant. Most house plants do best in a pot barely larger than the root system. Also, the depth of pots will cause soil to dry more slowly. How did you pot them? Lots of shards or gravel at the bottom? I hope not because that will also slow the drying of the soil.

You have quite a variety there, all with their own specific needs. I hope you have done some research on their care.

Hi Daisyl,

Thank you for your reply.

I do have a lot of plants of different varieties... and am just beginning to learn more about each. I do have a spreadsheet that I made with info on care for each, which I can share if that helps.

I don't think the spider mites aren't a problem anymore. It seems like my main concern now, as you've pointed out, is the mildew, due to overwatering? That would make sense.

Many of my plants were heavily root bound when I bought them, so I repotted many of them to a size +2in in diameter. I may have gone too big on some of them, it seems. The ones that were repotted had wood chips at bottom, well-drained soil, sometimes mixed with a bit of gravel and sometimes topped with a bit of wood chips.

It seems like the culprit for the Ti plant and Dieffenbacchia is overwatering, with mildew, considering they're the only ones that show signs of black mildew on them? What should I do now, other than wait for soil to dry and not water less often..? Is this a bacterial problem I should treat somehow?

Thanks!

What kind of soil did the plants get potted into? What kind of drainage does the soil provide?

Did you know that it's best to keep the soil a little loose. You want to drop the soil in and tap the pot to settle the soil and add more, and so on; until the soil hits the plant at the same place it did in it's original pot. Avoid packing down the soil, as this will inhibit air from getting around the roots. Plant roots need a combination of water and just as importantly, they need oxygen. Watering gives the water, and the dry time you give between waterings is when they get the oxygen. Dry time is a very important part of care. It's very important to have soil that will drain well so water does not languish in the pot, as oxygen cannot get to the roots and they suffocate. As for the mold, I think your best bet is to let the plants stay dryer longer, and remove damaged leaves.

You mentioned spots that could be bugs but don't move. Are they a bump. Can you flick it off with a fingernail. If so, it's probably scale, which can cause molding. Google scale, and you will see what they can look like and how to deal with them. You can take a qtip dipped in rubbing alcohol, and touch each dot or scale and they will die.

Your plants are still healthy enough to recover. This is a great place discover how fun they can be.

You have many plants with many issues to address here. Let me start with some basic observations.

Light: If a plant does not receive adequate light, then it won't matter if you do everything else perfectly. The intensity of light drops off dramatically with every foot of distance from the window. Few plants will do well more than 3-5 feet from a window. Some of your plants have to be directly in front of and close to a window.

Repotting: Unnecessarily repotting new plants is the most common mistake folks make and is the most common cause of plant problems. Plants are best left in their nursery pots with the potting mix used by the growers. Repotting can severely traumatize the roots if not done correctly. Larger pots add excess soil that takes a long time to dry out properly and greatly increases the chances of root suffocation. Failing to use the proper potting mix adds to the problem. It is much better to leave plants in their nursery pots. The nursery pots can then be double potted into more attractive planters if you choose.

The combination of reduced light and large pots with improper potting mix create problems that are very difficult to overcome.

More to come.

(PS I work professionally in NYC. Feel free to contact me directly at 917-887-8601)

New plants should not have pests. If so, re-consider your plant source. When there are plant pests, there are usually other problems with the plants. Pests thrive on plants that are under stress due to inadequate light, improper watering and damaged root systems.

Spider mites can be successfully treated with any liquid dish soap and water. No other ingredients are necessary as long as you get complete and thorough coverage of every leaf and stem surface until they are dripping wet. Mites are so tiny that they easily survive between the droplet of spray. Thus, the soap solution wash over all plant surfaces to be successful. It is not so much WHAT you use to spray, but HOW THOROUGH you are in applying it.

Your Ti Plant is way too far from the window. It should be within 2 or 3 feet of a window. The roots are dying due to the repotting. What kind of soil did you use when you repotted?
Frankly, I don't think the Ti Plant can be saved and certainly not in that location.

The light location for your Dieffenbachia is fine, but the repotting was not. The soil needs to dry out about two inches deep into the pot approximately every 7-10 days. Apparently, yours is not and that means the roots are suffocating. When plants in the Aroid Family, including Dieffenbachias, have rotting tissue it has an unpleasant smell that some folks associate with tobacco. It is a root problem and no sprays will help. This plant has a chance to survive if you are very careful to water very moderately.

Please describe the potting soil you are using. That may be part of the problem

I cannot determine the location of the Birds' Nest Fern. It does not need direct sun rays falling on its foliage, but it should otherwise be within a few feet of a window. This plant can tolerate damp soil better than most. As with the others, I am concerned about the repotting and the quality of the soil used. Water it as soon as the top half-inch of soil feels dry.

Your Anthurium appears to be in a good light location and appears to be in generally good condition. As with the others, I am concerned about the repotting. Anthuriums are epiphytic, meaning that they require a very loose, unusually porous potting medium. Given the pot size and the soil you used, there is a real danger that the fragile roots will rot over time.

You have mentioned a couple of times that the soil is staying moist longer than you expect with several of your plants. That is indicative of a too-large pot with too much soil and a potting mix that does not dry out soon enough. Inadequte light will also factor into the soil staying moist for too long. (See my original post.)

Your "Prayer Plant" is a type of Calathea. (One of the Species Sleuths here will provide a more precise ID.) I am delighted to see that you left it in its nursery pot and double potted it appropriately! That is the way to go in the future and it is much easier that repotting and using questionable potting mixes.

The light looks ok, but it may need to be moved out of the corner a bit toward the window. Protect it from the afternoon sun falling directly on its leaves. It is a fairly fragile plant with leaves that are easily damaged and not very forgiving of watering lapses. It is best to water it as soon as the surface of the soil feels almost dry or barely damp. If you are off by much either way, you will get leaf edge damage. You may want to remove the pebbles so you can better assess the soil moisture. It generally prefers high humidity but can do well in dry air if properly watered. Fertilize very sparingly, if at all.

Calatheas are mite prone. Treat them with a mild soap solution and avoid any oil sprays. After treating with soap, rinse it off.

NYC apartments are notorious for too much heat and extremely low humidity. Listen to WillC as he is living in the same situation. He is a professional!
But when you bring a happy and healthy plant home and it has gone from proper humidity to BONE dry and from appropriate temperatures to TOO HOT due to the longer winter and an apartments heating system you are bound to have trouble. There is an adjustment period. Give it some time. Increasing the humidity is probably a good idea and a bit healthier for the human inhabitants as well. But let WillC advise you.
Meanwhile good luck! Having plants in the home can be very soothing!

Your Rojo Congo Philodendron is in good shape for now. However, I am concerned about the large pot. Fortunately, this plant can tolerate moist soil better than some of the others. The roots you referred to are aerial roots that do not need to be covered with soil and are not an indication that it wants a larger pot.

The light location is good. Water it only when the top inch of soil dries out. Add just enough water so that it reaches that level of dryness again in about a week. Adjust the water volume accordingly. Trim off any discolored leaf tips or edges. Most of the discoloration is due to the repotting. The "stretch marks" are normal.

Here are some random, unsolicited thoughts on your other plants:

1. It is best to get plants in the best location and leave them there. Plants don't like to have to make frequent adjustments to changes in light. Rotate your plants in place, but not with each other.

2. Your White Bird of Paradise needs maximum light and water. It will grow rapidly and soon outgrow its space. Older, side leaves can be trimmed off to keep it in check.

3. Your Cactus need to be right in front of the window rather than between the windows where light is greatly reduced.

4. Likewise, move your Fiddle-leafed Fig out of the corner to give it maximum light.

5. Your Pencil Cactus also requires maximum light and should be more centered in the window.

6, The Yucca has to be moved right in front of the window. Allow the soil to dry down 1-2 inches before watering it.

7. The succulent near the Yucca also needs better light. Switch it with the Snake Plant that can survive lower light much better than most of your other plants. There are many low light plants that will do better away from the windows.

8. Big Bill's comment about very low humidity in our overheated NYC apartments is generally true. However, it is hard to increase humidity significantly without a large humidifier. Misting does little increase humidity. Pebble trays will help individual plants. But most of these plants have proven they can do pretty well in low humidity when watered properly.

9. Not sure the source of your spreadsheet information, but I do know there is a lot of very inaccurate information available on the internet.

10. No wood chips! They are a common source of fungus gnats when used indoors. The idea of adding drainage material to the bottom of pots is out-of-date and discredited. If possible, remove any chips from the bottom of the pots. For sure, your plants do not need bark chips or any other mulch on the surface. Remove them so the soil in the root zone can better dry out and receive oxygen

More information than you bargained for! Let me know if any of this is unclear.

THANK YOU ALL SO MUCH FOR YOUR FEEDBACK & TIPS!

I've been meaning to write back, but am so busy with work, unfortunately I only have the weekends to (barely) take care of my plants. I'm like a premature parent, who adopted 30 babies all at once - please forgive all the novice mistakes and the irresponsible neglect due to lack of time.

A general question that came up from all of you is which type of soil I used in repotting. I mainly used:
- Miracle-Gro® Moisture Control® Potting Mix
- Miracle-Gro® Cactus, Palm & Citrus Potting Mix
- I would put some wood chips at the bottom (which now I understand, per your comments, was a mistake - the home depot guy told me to!),
- Generally mixed the soil with a bit of gravel to allow for air pockets (at least that was the intent; you can confirm if that was also a mistake)
- And sometimes added gravel and wood chips at the top. (Per your advice, I have removed most of the gravel and wood chips at the top. I haven't had the chance to remove the bottom layers yet - do you think this will be necessary, and if yes, urgent?)
- The soil was not too compressed - just enough to hold the plants upright. Then they were drenched in water (and properly drained) to compact the soil.
- I also often, now, as a desperate remediation 'technique', poke the soil with a chopstick to provide air holes deep into the soil (dad's advice), and also work the soil with my hands (a few inches deep) to loosen it and bring the locked moist soil to the surface.
- All the pots have drainage holes, but perhaps some may need more.

What are your opinions on adding sand as a top layer to help dry out faster, and prevent fungus gnats (which I will bring up later as well)?

Laurie,

You mentioned the possibility of the black dots being scales - I had thought that too, but upon googling images, they don't quite look like scales. Mine are rare, separate single dots, all black. I suspect they may be first specs of mold appearing..?

Regarding potting soil and techniques I used, please refer to my previous post. I think I did as you have described - added a bit of soil at bottom, put plant in, added soil all around it to fill up to same height of plant (unless plant seemed root-bound with roots hanging out all over the top - which, apparently is normal and I should not have repotted or added soil over them? But how do they receive water?)

Thanks for the warm welcome and I'm always open to more tips!

BigBill said:NYC apartments are notorious for too much heat and extremely low humidity. Listen to WillC as he is living in the same situation. He is a professional!
But when you bring a happy and healthy plant home and it has gone from proper humidity to BONE dry and from appropriate temperatures to TOO HOT due to the longer winter and an apartments heating system you are bound to have trouble. There is an adjustment period. Give it some time. Increasing the humidity is probably a good idea and a bit healthier for the human inhabitants as well. But let WillC advise you.
Meanwhile good luck! Having plants in the home can be very soothing!

Thanks for the feedback BigBill.

Here's the caveats about NYC apartments in the winter, and specifically mine, AND specifically this year.
- Outside temperatures have been fluctuating a lot this winter, going from above to below 0 in the same week (apologies, I speak in Celsius, as I am Canadian and haven't been able to accommodate myself to your odd unit systems yet :P)
- My landlord is quite stingy on providing heating, despite NYC laws, but I don't want to argue with the lady living downstairs, unless it comes to a point where I really have to. Picking my battles, if you know what I mean. That being said, she typically doesn't turn the heat on on weekdays during the day, and on Sundays when she goes to Church, and basically when she's not there or not feeling cold. As such, I have bought a small space heater.
This means temperature and humidity is erratic in this household - and hard to predict or control.
- Additionally, the two windows in the living room (with the square glass) are old and were rendered inoperable. They're however not perfectly sealed and do leak cold air from outside in. This makes my plants near the windows (where they should be if they require a lot of light) vulnerably to frost damage and leaf browning/curling. In fact one of these windows sits in front of a radiator (which as mentioned, is sometimes steaming hot, and sometimes not on...)
- All other windows (one in kitchen and the two in the bedroom) are newer and operable, but do let some cold air in still.
- As a side note, I have a small skylight in my mini bathroom (off my bedroom), which seems not perfectly sealed as well, since snow was softly trickling in, when we had a 'snow storm' the other day (quotation marks due to relativity of the definition of 'snow storm' for New Yorkers vs. Montrealers). It was quite beautiful, actually.
- I also have (2) small 500ml aromatherapy diffusers, one in each room, which help a tiny bit with adding humidity. The problem is that many of my plants require humidity and others not - especially the ones that I have been overwatering/have poor drainage/have fungus gnats, so it is difficult to balance it all.

On the subject of balance for the environment of each plant in this small NYC apartment, I will follow-up in more detail in a following reply to WillC's responses.

WillC said:Here are some random, unsolicited thoughts on your other plants:
[...]
More information than you bargained for! Let me know if any of this is unclear.

WillC - Trust me, no advice is unsolicited and from my perspective, I have gotten a great bargain package deal! So thank you for your detailed responses! The more information, the better - and I actually had more questions to ask (some of which you have taken initiative to answer already), but didn't want to overwhelm everybody! I was scared writing the life story of me and my plants would deter people from reading and responding! I am pleasantly surprised everybody has been very welcoming and helpful.

Now... All specific responses to follow...

WillC said:You have many plants with many issues to address here.

Light: If a plant does not receive adequate light, then it won't matter if you do everything else perfectly. The intensity of light drops off dramatically with every foot of distance from the window. Few plants will do well more than 3-5 feet from a window. Some of your plants have to be directly in front of and close to a window.

This is true - and I have started mentioning some caveats on this issue (differing environments required for different types of plants + apartment specific contradictions) in my previous response to BigBill above. The problem with moving some of the plants closer to the window as your have suggested is that I fear they may be subject to frost and/or radiator heat. I also suffer from paranoia of putting all my plants in one spot, and infecting each other with whichever problems each may have. For eg., I have been paranoid of putting any plants in the corner were my Cat Palm used to be, before it got infested by spider mites and had to be thrown out. I guess I will just have to get over it, as there seems to be no more signs of spider mites.

WillC said: Repotting: Unnecessarily repotting new plants is the most common mistake folks make and is the most common cause of plant problems. Plants are best left in their nursery pots with the potting mix used by the growers. Repotting can severely traumatize the roots if not done correctly. Larger pots add excess soil that takes a long time to dry out properly and greatly increases the chances of root suffocation. Failing to use the proper potting mix adds to the problem. It is much better to leave plants in their nursery pots. The nursery pots can then be double potted into more attractive planters if you choose.

The combination of reduced light and large pots with improper potting mix create problems that are very difficult to overcome.

Oops Looks like I dropped the ball on this one and committed a novice mistake! Fortunately, I think the pots I have used are not significantly too large, and hopefully my plants can grow into them? I believe most of my plants are still healthy enough to overcome this? *crossing fingers for positive validation* I know repotting in the spring, when the plants are not idle, would have been much more ideal, but at the time I thought my plants were severely pot-bound and needed immediate repotting. Thankfully, I did not repot them all!

Good drainage gets taken care of by using a good potting mix that has adequate perlite mixed throughout. There is no need for "drainage material" at the top or bottom of the pot. Perlite is better than gravel because perlite granules are porous and they are also lighter in weight.

Again, with a porous potting mix, there is no need to poke holes in the soil or stir it up with your fingers. Plant care is so much easier if you start with a good potting mix. A single drain hole large enough to release any excess water in all that is needed.

When repotting, never add soil to the top of the original rootball. Roots exposed on top are either aerial roots or roots that have callused over and they do not need to be covered.

Sand will not help the soil dry out faster. In fact, it may have the opposite effect. A good potting mix will dry out properly all on its own as long as you don't water too often. Sand on the soil surface is sometimes recommended in treating fungus gnat larvae because the sharp edges of the sand carve up the larvae as they move through it. A better solution is to use sterile potting mix; don't over pot; and allow the soil to dry as deep into the pot as possible.

At this point, it is probably best to leave whatever stuff you put in the bottom of the pot. Just skip it in the future.

Plant care advice at a Big Box store is rarely reliable.

None of your plants require increased humidity. That is one less thing for you to worry about.

WillC said:(PS I work professionally in NYC. Feel free to contact me directly at 917-887-8601)

Be careful of your offer - you might be getting calls from me more frequently than anticipated!
When you say 'work professionally', what does that apply / what do you do? Do you work in a nursery? Do you have business hours, or can I call you at any reasonable time? :)) And Thanks!!

I work as in indoor plant consultant and I care for hundreds of plants in commercial and residential spaces in Manhattan. I also make "plant doctor" housecalls in Manhattan. I have been doing it for over 30 years. I take calls from all over, 9 AM to 9 PM, 7 days. Feel free to call.

I have also written a book on plant care, "Don't Repot That Plant."