Q. For the last 5 years or so my zucchinis have failed to set fruit. They blossom prolifically, but show no sign of fruiting. I have tried different varieties, different environments (even planted one-half mile away) with the same result. No one seems to have heard of this problem. I have tried insecticides, no insecticides, lots of water, little water but still no results. I used to always have a huge crop. — Bill Michaels, Adams County, Ind.
A. If this occurs early in the season, the most likely reason is that the plant’s female flowers have not yet begun to open. Zucchini produce separate male and female flowers. They both have to be open for pollination to take place. Generally, male flowers open first followed by female flowers. Lack of proper pollination in the summer due to cold, rainy weather or a lack of insects for proper pollination can also result in a lack of fruit set. You might try hand pollinating by transferring pollen from the male flowers to female flowers with an artist’s paintbrush. Be careful with insecticides. Some are quite deadly to bees, which are the major pollinators of zucchini.
Q. I have 3- to 4-foot Brussels sprout plants that have only leafy little heads, instead of solid ones like you see in the store. Do you need to take off some of the large growing leaves late in the season? I have about 50 cauliflower plants and only one halfway made a head. Might the same apply to them? — Ozzie Luetkemeier, West Lafayette, Ind.
A. If the sprouts develop in hot weather as summer warms up, or from a fall seeding if the fall is warm, they may form loose, leafy heads. Use transplants for early plantings and maintain ample soil moisture. You also can cut off the top growing point when the plant reaches 24 to 36 inches in height. This redirects the plant’s energy from leaf production to sprout production.
Evaluate the variety you’re growing. Newer varieties mature faster and will provide a more dependable yield. ‘Bubbles,’ ‘Oliver’ and ‘Royal Marvel’ mature in less than 90 days.
Sow Brussels sprout seed 4 to 5 weeks before transplanting. Set your transplants in the garden in early summer to midsummer, at least 90 days before first frost for a fall crop. For summer harvest, you must plant transplants of an early, heat-resistant variety in very early spring. A fall crop is most likely to give you a satisfactory outcome.
Cauliflower is considered to be a cool-season vegetable. High temperatures can cause small leaves to form in the head, unsatisfactory texture or a lack of head formation. The optimum temperature for curd development is about 63 F but will be satisfactory until temperatures reach the upper 60s to mid-70s, depending on the cultivar.
It is important to plant cauliflower early in the spring to allow the plants to mature while temperatures are still cool. Using transplants, rather than starting from seed, will give you a considerable head start on the growing season. When choosing transplants, look for relatively small plants because large plants with very thick stems tend to produce buttons or very small curds.
On the other hand, planting too early can be risky. Freezing temperatures can cause “blindness,” which is the lack of head development. If late freezes are predicted, cover plants with newspaper tents, hot caps, blankets or insulating mulch overnight.
For more information, contact the Purdue Extension office in your county and request a copy of “The Fall Vegetable Garden,” HO-66.
Q. My yard is really flat and has about 4 inches of top soil and then turns into brown clay. It seems difficult for me to grow most plants, trees and flowers. Are there many varieties that can tolerate these adverse growing conditions? If so, is there a list I could obtain or send away for? — Larry N. Barnes, West Harrison, Ind.
A. Amend your ways! You’re doing the right thing by researching which plants will survive the conditions. You can meet the plants halfway by amending the soil when you plant. Turn in compost, rotted leaves, pine needles, grass clippings and other forms of organic matter to improve the soil structure and fertility. Make sure you mix the organic matter with the existing soil. If you backfill with straight compost or black dirt, you’ll create a bathtub effect.
When you plant balled-and-burlapped plants, raise the rootball slightly above soil level. The University of Minnesota has a nice list of plants adapted to clay. You can see it at https://www.extension.umn.edu/garden/yard-garden/trees-shrubs/trees-and-shrubs-for-clay-soil/