Q: Dear Dave,
I have been dealing with problems of whiteflies. I keep seeing them come back in less than 1 week each time I spray insecticide. I think they may be immune to it and that the natural enemies have been eliminated by the insecticide that I spray. My question is, how do I effectively get rid of the whiteflies, once and for all? I have flower buds all over the branches now but I can see that many buds are turning yellow and dying off. Is it due to the insecticide that I sprayed? Does the spray have impact on flowering? For your info, I have stopped using fertilizers as I had a previous case of over-fertilization that caused the flowers to drop.
A: Hello Cindy:
Maybe you are using the wrong insecticide. I recommend Raid Flying Insect Spray. It works very well for me. It is important to cloud the plants with the spray rather than to spray directly on the plants. If you are spraying directly, it could be causing the buds to drop off. Some drop off is normal. Over-fertilization causes excess leaf growth and bud drop off. You should flood irrigate your plants to remove even more fertilizer, assuming that the soil drains well. Another cause of drop off is excessive heat, which is impossible to control.