We recently built a new house and now I have a sunroom to work in. My problem is this. I keep geraniums, clivia, coleus, hibiscus and several other houseplants in there. All seem to be doing well, except for the clivia and coleus. Out of all the plants, only the coleus seems to be getting a mildew. I don't know if there is a specific strain of mildew that attacks only coleus but none of the other plants gets it. Any advice? As for the clivia, it flowers but the flower stalk never gets any higher than the leaves. Anyone knows what causes this? I really would like to see a grown up plant! Thanks. Marg
You're keeping the Clivia too warm during flower formation. It's a sub-tropical plant that requires cooler seasonal temperatures to initiate flowering and to facilitate stalk growth. Nighttime temperatures between 5 & 15ºC from late October until the flower stalk is 2/3 the height you'd expect it to be should be enough...then you can bring it out for show. As for the coleus, I think air movement would help cut down on the mildew. The coleus is also a tropical...its ideal conditions are much warmer than the expected winter conditions for geraniums and clivia.
If the stalk is already stunted for this year, you may as well forget the unused bedroom and try for next year.
