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by Ann
(Deal, Dover, England)


My first question concerns two Crassulas in my collection, cotyledon and perfoliata, which are both suffering from what looks like black mould. They have been in my greenhouse (pictured) with the doors open day and night during the summer, but could this be caused by lack of air flow? I’ve moved them outside now in the hope that this might help?

Second is the propagated young plant. The leaf which I propagated is now obviously dead but the roots on the new plant just won’t root. I’ve had this on damp compost for about five weeks now but they don’t seem to want to root themselves. Is there anything I can do to encourage them, please?

Comments for Two for the price of one, please?

Sep 15, 2022

by: Jacki Cammidge, Certified Horticulturist

I’ve seen that on plants, and it is more than likely to be mealy bugs. They are like aphids, producing sweet secretions in their poop, which is what the mold grows on. Deal with the mealy bugs with an alcohol and soap spray, several to many times – good luck and persistence wins out.

For the little plant, as it has already leafed out into an actual rosette, it doesn’t need the mother leaf, so it has shriveled.

It should root in time, but generally I use dry soil which encourages them to seek out moisture. Maybe see if you can allow it to dry out a bit, and only spray nearby on the soil instead of really close to the plant.

Sep 16, 2022

Thank you
by: Ann

Thank you once again Jacki. I never thought that the ‘mould’ could be caused by an infestation, so I’ll start spraying today! I’ll also move the plantlet to dry soil.