Root mealies or worse

[gabby c]

Hi

This is not the first time I’ve posted about root mealies . I actually have been dealing with them ever since! Last fall I noticed abnormal growth on my gasteria and unpotted to find root mealies. I washed and repotted with new soil. A month ago I unpotted my ariocarpus seedlings and found root mealies and that was my last straw. Two weeks ago I treated all my plants with the bonide tree and shrub; this is the first time I’ve used pesticide treatment.

I dunked the pots in water with a ratio of 4Tbs bonide per 1 gallon water.

Anyways, my gasteria had some normal growth but it looks like bad growth is happening again. I am worried it is another pest.

I rent a house in Florida and my “yard” is sick. My oak trees have some type of mite, my palm tree has scale, my weeds are covered in mite damage too. I see red mites running around my pots. Aloe mite is my worse fear but I do not grow ANY aloe. Doesn’t mean they couldn’t come from someone else . I’ve been building my collection and have many new plants from many sellers.

Would love to hear other opinions on my gasteria. I have 2 other gasteria armstrongii next to this one and it’s the only one showing bad growth. It’s also the oldest being from 2017, the other two have been in my collection since 2022 and 2020.

[ohugal]

I wonder what that discoloration is at the base on the inside of the leafs...
What is the bad growth you are referring to? If it is has stopped growing all together it is best to check the root system.

Some of the members here swear by systemic insecticides. I don't have much experience with it since I'm in Europe and laws are stricter here on the use of systemic insecticides for private individuals. As a first step I would quarantine plants of which you think they have a pest to prevent further infestation. What is the size of your collection? If I discover a plant has root mealies, I remove as much soil as I can. The soil goes into a bag which is sealed immediately and put out with the trash. I rinse the plant with a hose. Not in the garden, but rather in my shower or a bucket. I then soak the plant in a contact insecticide. This depends on the size and the amount of plants. The plants which still have clumps of soil attached to the roots, I soak for a longer time. Sometimes I repeat this step a week or two later. A more ecological way is the hot bath method as described on the forum. I have used it in the past, largely with succes. The only plant which reacted bad to it was an Agave victoriae-reginae.

For a systemic insecticide to work your plant has to be actively growing. If that's not the case, it won't have the desired result. That I do know. I also saw some members here actively discussing the concentration of imidacloprid based insecticides at a certain point.

[gabby c]

Thanks ohugal. The discoloration is what I think is bad growth. It’s slightly raised too. I should unpot it and look but since I unpotted and took a lot of roots off not to long ago I was hesitant to do it again. I know it’s growing and the plant rooted well again (tug test). I don’t quarantine because I don’t have much space for my plants. I could build a quarantine shelf…

I have about 200 pots. I usually remove soil, toss in the trash, and wash the plant like you describe which has always worked well for the individual plant. They don’t come back usually. But months later I notice another plant or two struggling and alas there are mealies! It’s been going on for a few years.

I had read on the forum about the concentration of imidacloprid which is where I got my 4Tbs to 1 gallon ratio. I had not read about the plants needing to be in active growth! That’s good to know. My haworthia and gasteria are actively growing but I am not sure about my cactus. I think they are just starting if at all.

[Steve Johnson]

I had read on the forum about the concentration of imidacloprid which is where I got my 4Tbs to 1 gallon ratio. I had not read about the plants needing to be in active growth! That’s good to know. My haworthia and gasteria are actively growing but I am not sure about my cactus. I think they are just starting if at all.

I think you might've seen this presentation before:

viewtopic.php?t=42129

A whole lot of detail there, so I understand why it's easy to miss key points like -- plants needing to be in active growth when we give them Imidacloprid soil soaks. Haworthia and Gasteria are normally winter growers, although if yours are growing, the soil soaks you did a couple of weeks ago was a good call. If you're not sure about whether your cacti are growing, you may want to give them another soil soak next month.

Using the same pesticide all the time could lead to eventual pest resistance, so it's best to rotate pesticides whenever possible. This is a good one:

viewtopic.php?p=397417#p397417

Craig and Denise Fry are expert growers, so if I were you, I wouldn't think twice about putting Cyzmic CS into the rotation.

Since you're dealing with what I call "sick garden syndrome", using Imidacloprid and Cyzmic as preventatives on a regular basis may be helpful. Same applies to the miticides I discussed in my presentation.

[gabby c]

Hi Steve, that is right, I used your original mealies thread for instruction! Lots of great information. Thank you!

[Steve Johnson]

Hi Steve, that is right, I used your original mealies thread for instruction! Lots of great information. Thank you!

You're welcome!