Question
QUESTION: Hi Will,
I've been searching online for some help with my Dracaena. I inherited it about two years ago and it seemed to be doing very well until the last couple of months. I was out of town and I think my friend who came over to water the plants overdid it. The plant is about 5 feet tall with three large stalks, each with several branches.

Weeks ago, once I got back in town, I noticed that the leaves started yellowing on it and dropping off - about a dozen every couple days. It was really dramatic. After researching online, I decided to repot the plant. It has been in the same pot for probably 5 years and the roots were growing out of the bottom of the pot, so it seemed to be the right thing to do. The person at the gardening center talked me into getting some organic potting soil and out of getting anything to mix it with.

The repotting seemed to go well. I've repotted plants before - although not one quite so tall. The plant seemed happy for about a week and then the leaves started yellowing and dropping again. That seems to have slowed a bit now, but yesterday I noticed that the topsoil is covered in a gray/white mold!

So I've been doing more research and am not sure what to do. I could scrape off the moldy soil, but what's to prevent it from molding over again? I read about spraying it with a mixture of water and either hydrogen peroxide, baking soda, or tea tree oil. I've also thought about buying a light and keeping it on the soil to heat the mold away. But I am hesitant to take any action for fear of making things worse, but I don't want the plant to suffer.

I really love this plant and want to see it thrive. I have lots of happy houseplants and have never lost one before. What would you recommend? Please let me know if you need more information.

Thank you so much,
Kathleen

ANSWER: Hi Kathleen,

I'm sorry you have been victimized by some very poor advice.

You didn't mention it specifically, but based on your description, I am assuming you have a Dracaena marginata, not one of the other popular Dracaena varieties. Marginatas are quite fussy about their watering and lose leaves in bunches when not watered properly. It seems that the over watering by your friend is what caused the problem. The proper solution was to simply allow the soil to dry out more thoroughly before you resumed your normal watering routine. Unfortunately, you decided there was a larger problem and you found the common, but incorrect advice that repotting was in order. Unnecessary repotting is the single most common cause of plant problems.

An over watered plant needs to be able to dry out so oxygen can get back into the root zone. Repotting not only disturbs the already compromised roots, but it adds more soil that retains moisture even longer rather than allowing it to dry out.

The word "organic" is used very loosely so I don't know exactly what potting mix the garden  person used. However, it should have been a very porous mix of mostly peat moss with extra perlite mixed throughout. Any other heavier potting mix is inappropriate because it lacks porosity and compounds the water/root rot problem.

In this case, the organic soil used was not sterile and certainly was contaminated with fungus spores. That is why you are having a mold problem and will continue to have this problem no matter how many chemicals you put in there.

At this point, your Marginata may be beyond saving given what it has gone through. There is only one way to go and it may be too late. Undo the repotting that was done, removing all of the "organic" soil that was added. That will help eliminate the mold and the spores. (I suggest you take that moldy soil in a bag and dump it on the garden center employee's desk!) Try to get back to the original rootball with healthy roots. My guess is that many of the original roots are now dark, soft and mushy. If so, you will have to carefully remove them along with any soggy soil around them. Do not wash away all of they soil. You are looking for firm, healthy roots. Assuming you find some, keep just enough surrounding soil to keep them covered.

Then, move this slimmed-down rootball and soil into a pot that is barely large enough to accommodate them. The goal is to get the roots into the SMALLEST pot with just a minimum amount of soil. This will allow the soil to dry out more quickly between waterings. Assuming you get this far, recovery will be long and very slow.

If you do not find any healthy looking roots, then your plant is history, thanks to the poor advice you received. I am sorry to present this gloomy picture, but I have seen the results of unnecessary repotting so often that I know the usual results.

I have written an article on repotting that I will email for free to you (or anyone else) who emails a request to me at [email protected].

Please let me know if any of this is unclear or if you have any additional questions.

If this information has been helpful, please click the Rate Volunteer bar below and enter a rating and nomination for me. I am a volunteer on this site so Ratings are the only compensation I receive for answering plant questions.

Need more information? Visit my website at:
A link to HorticulturalHelp.com

or email me at [email protected] or call me at 917-887-8601 (EST)
 
Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

Visit my website at: A link to HorticulturalHelp.com




---------- FOLLOW-UP ----------


Monstera  
Dracaena   QUESTION: Dear Will,

Thank you so much! I cannot tell you what a relief it is to hear real advice about my poor plant. I'm including a picture of it (Patient #1) to make sure it is a Marginata. I will get some new soil and perlite and hope for the best. I haven't watered it for weeks and it's definitely still wet. Would rooting hormone help? Or anything else I can give it? (Aside from a smaller pot and better draining soil)

I have one other plant that I have trouble with (see picture Patient #2). I inherited this one as well. I believe it is a Monstera Friedrichsthalii, but again, that's just a guess.

The trouble with the original plant is that it grows very quickly, has good leaf color, seems robust and then leaves start to yellow and others get brown splotches until whole branches are left bare. This plant has gone through this before and survived. I mistakenly thought repotting saved it the first time and so I repotted this one about three months ago. It flourished until the last several weeks when it lost dozens of leaves to yellowing. There's also the brown splotches. And the soil looks like it has white crust on it. Perhaps this is a root rot situation as well? Follow the same protocol?

Thank you so much. You've been so generous with all of your expertise. I really cannot thank you enough.

Best,
Kathleen

ANSWER: Hi Kathleen,

I realize I may have confused with my previous reply. When I mentioned appropriate potting mixes for indoor use, I was speaking generally. For your Marginata, and it is a Marginata, your should not be replacing or adding any soil. You should remove potting mix that was added and any of the original soil that is filled with rotted roots that should be trimmed off. Leave in place all soil that is in immediate contact with any healthy roots. Move the smaller rootball to the smallest pot that it will fit into so that you do NOT have to add any new soil. Rooting hormone will not help. There are no quick, easy or shortcut solutions here.

It is likely that your Monstera is also staying too moist due to the ill-advised repotting. Monsteras are a bit more tolerant of wet soil than Marginatas so it may not be necessary for you to undo the repotting unless you have similar mold and critter problems. Scrape off the white crust and remove any surface soil not in direct contact with the roots. Allow the top 2 inches of soil to dry out before adding a small amount of water.

The key to watering potted plants is allowing them to dry out deep enough into the pot so that the roots receive oxygen. Moving plants to larger pots and using heavy organic soils delays that drying out process and leads to root rot.

Your Monstera will also benefit from being pruned back sharply. Any vines that have lost more than 3 or 4 leaves should be pruned back to about 2-3 inches above the soil. If the roots are still healthy, new growth will emerge on each vine just below the pruning cuts. This will eliminate the bare vines and create a fuller, more compact plant.

I have written an article on pruning that I will email for free to you (or anyone else) who emails a request to me at [email protected].

Please let me know if any of this is unclear or if you have any additional questions.

If this information has been helpful, please click the Rate Volunteer bar below and enter a rating and nomination for me. I am a volunteer on this site so Ratings are the only compensation I receive for answering plant questions.

Need more information? Visit my website at:
A link to HorticulturalHelp.com

or email me at [email protected] or call me at 917-887-8601 (EST)
 
Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

Visit my website at: A link to HorticulturalHelp.com




---------- FOLLOW-UP ----------

QUESTION: Hello Will,

Thank you for getting back to me so promptly! You're incredible! If these plants make it - it's because of you. So I sincerely thank you.

I just repotted the Marginata an hour ago. Surprisingly, I did not see any rotting roots. All the roots on the outside of the ball looked like delicious parsnips. I didn't dig any further into the ball for fear of hurting it. However the smallest of the "trees" almost fell over entirely while I was trying to move it, so I do think there's some kind of root issue. Maybe it just got damaged when I first repotted it? Anyway, I downsized the pot, but the rootball was too big to make it to the bottom of the pot, so I did put soil in the bottom three inches with a good amount of perlite in it so it wouldn't be empty beneath the root ball. After reading your latest response, I hope this was the right move. This new pot is ceramic, so that should help with the moisture as well. I covered it with a couple more handfuls of that soil mixture, just to cover the exposed roots. It's alright for the roots to be right up against the inside of the pot? I hope so, because I really don't want to disturb the poor plant again!

Also, I didn't see any mold or insects past the surface, but there was an awful lot of soil. Should I assume it is all contaminated? Is there a way I can test it? Or sterilize it? I haven't seen any mold on the other plants that I potted it with. The brand, by the way, is Fox Farm, Ocean Forest mix. Just curious if there's a way I can avoid having to just pitch it.

Thank you for the advice on the Monstera as well. I will get out the shears and lay off the water for sure. I'm considering making a moss pole for it to climb. Maybe that will help. It's aerial roots are impressive.

Well, suffice to say you've saved the day! Thank you again. Straight 10s!

Cheers,
Kathleen

Answer
Hi Kathleen,

Thank you for the top ratings. They are much appreciated. FYI, the other houseplant "experts" on this site lack the appropriate professional credentials and experience that I have, so caveat emptor. Feel free to contact me directly at [email protected].

It would have been better to find a way to slim down the rootball a bit more to squeeze the rootball to the bottom of the pot or use a slightly larger planter. Having excess soil, even at the bottom, is never a good idea. Many ceramic pots are glazed, which means they do not dry out any sooner than plastic. Many also do not have drainage holes. If yours does not, then you will have to use a pot that does.

The Fox Farm mix contains soil (humus) and worm castings and that is the source of the pest problems. Proper indoor potting mixes are soil-less, meaning they contain only peat moss, perlite and other inert substances and are sterile and pest free. I assume you removed all of the Fox Farm soil before you repotted. If you did, then the original rootball is probably uncontaminated.

Monstera are rather ungainly potted plants because their natural growth habit is as a vining plant. Wrapping the vines around poles is problematic unless the pole surface remains damp at all times. In addition, it doesn't take long for the vines to outgrow even every tall poles. I prefer to prune regularly and insert the cuttings in the base of the plant. I keep it short and compact. The aerial roots are largely non-functional when the plant is in a pot, so they can be cut off and discarded. In nature, they help secure the vines as they travel across the forest floor and up damp tree trunks.

~Will