My bush is flowering but it keeps losing leaves, turning yellow,dotted in blackish spotsThe upper leaves are still O.K. Something else is attacking it:On the newly formed leaves,the undersides are covered with tiny whitish bugs so much so it is hard to see the baby leaves.Last year,when I brought in my Datura from outside,the same bugs appeared almost overnight and I had to destroy it.Is it an acarian of some sort?Could the fertilizer I use be responsible for the leaf disease(15-30-15).I read 20-5-20 with micro elements like iron and magnesium would help perhaps .What do I do when I bring it inside for the fall? please help!!!!
the bugs sound like aphids and are easily dispatched with a strong blast of water from a hose. the black spots and yellowed leaves sounds like 'black spot' that roses get. it's a fungus. i don't grow hibiscus (yet...just got some seeds) so i don't know if they are susceptible to it or not. could also be the result of the aphids, too, maybe.
I use a systemic on all my non-edible flowering plants... It's protects against fungal too. Ortho Orthonex. Once a month application in the summer handles the business. I don't use it at all in the winter, beings I don't have the problems as I do in the hot/humid summer months of FL... There are some others on the market that're in the granular form... I think Bayer makes a Rose/Flower one that should do it too... Aphids are a real bugger; aren't they. They totally disrupt the BisCus from doin' what it does... :( ~LCA.
whitish and also affected datura sounds to me like it may be white fly. what type of hibiscus do you have the tropical or the hardy type ? white fly love the hardy types at least here in fla so i no longer try to grow them besides they donot do well for me for long they donot seem to like the soil here and take forever to break dormancy. most of the aphids i have seen are green than turn brown when they are adult maybe there are more varietys the only other one i have seen is a yellow one.i have never seen aphids on datura or brugmansia white fly yes. but either way i think the sestimic should work i have never used the sestemic bug killers i just have to many fruiting plants to risk spraying or pouring it around any of the plants and getting into the fruiting plants.
