Zucchini secrets & bolting spinach

Q: My zucchini always produce poorly. Because of my altitude, I grow them in a hoop house or low plastic tunnel, whichever you call it. They do grow and eventually they flower but I have lots more male flowers than the female ones which make a squash. What can I do to get better production?

A: It is a fact that zucchini are warm weather vegetables and their idea of an ideal summer is not what your garden can offer them. While you may not be able to create surroundings which will make the zucchini think they are growing in Missouri, you can create a microclimate somewhere on the road to there. Everything you do to warm the surroundings of your zucchini should increase its production. Since zucchini naturally make male blossoms before they make female ones, I suspect that your plants are only getting around to their first female flowers when summer is suddenly over.

First of all, your plastic tunnel should help to warm the air around a squash plant. However, good air circulation is critical to squash production. Why don't you try a compromise? Grow a squash in a tunnel until it makes flower buds. Then give it more air by raising the sides and leaving the roof or removing only the roof, whichever is easiest to accomplish. Do this every morning when the air warms up and restore the tunnel every evening before the nightly cold arrives.

Give your zucchini the earliest possible start in two ways. This spring, cover the square of ground where the plant will grow with plastic. A week under plastic will begin to warm the soil; longer will do no damage. Eventually, an organic mulch around the zucchini will conserve moisture and prevent weed seeds from sprouting. But do not apply an organic mulch until the dirt feels warm. If applied to cold dirt, the mulch will preserve the cold.

Second, start your zucchini in the house, just three or four weeks before you expect to move it to the garden. A longer time in a small pot would damage the roots. Plant half a dozen seeds and cut off the weakest seedlings until only two remain. Grow the last two all summer as if they were just one plant.

Whenever you expect a summer night to be cold, throw a cover over the zucchini. Floating row cover is the easiest to use but an old sheet or a few newspapers will also work. Do not use a plastic cover, since it provides little cold protection.

The combination of these ways to start the zucchini as early as possible and keep it as warm as possible should result in more squash before summer is over. By the way, I think the best-tasting zucchini are the Italian heirlooms. They have a variety of names but all of their squash have lengthwise ridges.

Q: How can I keep spinach from bolting to flowers so early in the summer?

A: When days get long enough, spinach will bolt, no matter what you do. However, you can maximize its time of making leaves in these ways: Plant as early as possible. If grass is beginning to turn green, the soil is warm enough for spinach seeds to germinate. Cover the planting with row cover to warm the ground faster.

Plant pinches of seed four inches apart for baby leaves, eight inches apart for big leaves. Gradually thin the smaller plants until only one remains at each spot. Cut the plants to be removed, do not pull them and thus damage the roots of those that remain.

Harvest single leaves as they grow big enough and cut the whole plant when it makes a flower stalk.

Starting now, on every sunny day use shade cloth or anything to keep the spinach partly shaded. I have found that shade postpones flowering by two or three weeks. And be sure that the soil never dries out.

Hackett welcomes reader questions related to gardening, pest management, plants, soils and anything in between. Submit questions to mhackett@centric.net, call 406-961-4614 or mail questions to 1384 Meridian Road, Victor, MT 59875.