Cactus Has White Fuzz On Top

Question

I have recently noticed my cactus developing white fuzz around the top area near where the flowers previously grew. I have seen reports about it being a bug infestation but I’m not sure. I haven’t seen any bugs and it just looks like it could be part of the cactus. Is it a bug infestation or something senior cacti do? (I’ve had mine for almost 12 years) If anyone can tell me what it is I would appreciate it.

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Answer 1

It looks like failed flower buds, but this can happen when flowers don't get pollinated, as well. I see quite a few pups at the base, as well. This can indicate a problem with the cactus' health.

I, also, notice that it is planted in quite a large container and in clay soil. This combination will lead to root rot, which appears to be what is starting, now.

Cacti tend to enjoy a cramped rootspace, and do not do well in moist soils. Most cacti need a to dry, very thoroughly, between waterings. In this large of a container, it will be even more important to let the soil dry out very thoroughly. You may need a moisture meter with a very long probe to be able to reach the bottom of that container in order to determine when it will be appropriate to water, again.

For now, I would treat with a fungicide. You may want to remove some of those pups and start them in small containers, in the case that the mother succumbs to the infection.

Here are some articles that will help:

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm

https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm

https://www.gardeningknowhow.com/special/containers/making-a-potted-cactus-garden.htm