Q: I’ve heard that squash and...

Q: I’ve heard that squash and melons have male and female flowers. Do both show up at the same time, and do I need to help things along by hand-pollinating?

--W.K., West Covina A: Unlike other vegetables, members of the cucurbit vegetable family have male and female flowers that both grow on the same plant. Mostly all early flowers are male; female flowers have miniature fruit just under the petals. For fruit set, pollen from the male flower must get to the female--usually by bees. Where there are no bees, hand-pollinating is necessary. Use a tiny brush to transfer the sticky yellow pollen to the female flowers’ centers.

Q: We live in an area with many avocado trees, but every one we plant dies. The nursery says it’s avocado root rot . Is it?

--G.S., La Habra Heights A: The root-rot fungus Phytophthora cinnamomi is a common cause of avocado tree decline. Symptoms of infection are smaller leaves that have a tendency to wilt and fruit that remains small. In the final stages of root dieback, twigs die. Avoiding water-logged soil slows down the spread of the disease and keeps an infected tree alive. The fungicide Terrazole will control the fungus but won’t eradicate it from the soil, nor is it much help in severe cases where most of the roots are dead.