When to Plant Annual Vining Herbaceous Zucchini, with Pollution-Free Cultivation Techniques for the Winter-Spring Crop

Zucchini contains relatively large amounts of vitamin C, glucose and other nutrients, and has the effects of relieving restlessness and quenching thirst, moistening the lungs and relieving cough, clearing heat and promoting diuresis, and reducing swelling and dispersing nodules. The zucchini fruit is used as a vegetable and is cultivated in all parts of China. So, when is the annual vining herbaceous zucchini generally planted? What are its benefits? What pollution-free cultivation techniques should be mastered?

I. When is zucchini generally planted?

For the autumn-winter crop of zucchini in greenhouses, sowing is generally carried out in mid-December for seedling raising, with planting in mid-January of the following year; ordinary cultivation takes place in March each year. Among cucurbit vegetables, zucchini is a type that is relatively cold-tolerant and not tolerant of high temperatures. The most suitable temperature during the growing period is 20-25°C.

II. Pollution-Free Cultivation Techniques for Zucchini

Growing zucchini in sheds and greenhouses mainly includes the autumn-delayed crop, the winter-spring crop and the early-spring crop. Because the winter-spring zucchini crop can reach the market during New Year's Day and the Spring Festival, its economic benefits are also relatively high. For winter-spring zucchini cultivation, sowing and seedling raising usually take place in mid-December, with planting in mid-January of the following year; harvesting begins around early February and ends in mid-to-late May. This zucchini crop is the earliest cucurbit vegetable to reach the market in early spring, mainly supplying the early-spring off-season market; it not only fills the market gap but also allows vegetable growers to obtain relatively high economic income from it.

1. What are the environmental characteristics of winter-spring zucchini cultivation in a solar greenhouse?

The zucchini seedling-raising period coincides with winter, when temperatures are low and light is insufficient, so different means are needed to raise the temperature and supplement light. The planting period is the time of the weakest light of the whole year; light intensity decreases, and after planting, the outside temperature gradually rises, so measures must gradually shift from heat preservation and light enhancement to cooling and day-and-night ventilation, until natural conditions are reached.

2. What is the main focus of pollution-free winter-spring zucchini production in a solar greenhouse?

(1) Under low-temperature and weak-light conditions, cultivate age-appropriate strong seedlings.

(2) Ventilate and release air.

(3) Frequently adjust the plants so that they grow in one direction, allowing the leaves to be reasonably distributed and receive light evenly.

(4) During the middle and late stages of growth, promptly remove the lower old leaves and diseased leaves to improve ventilation and light penetration.

3. How should seedlings be raised for the winter-spring crop of zucchini in a solar greenhouse?

The seedling-raising period falls in the period when the outside climate gradually turns cold to cold, so varieties that are cold-resistant, disease-resistant, and high- and stable-yielding should be selected.

Specific cultivation techniques:

(1) When selecting seeds, choose seeds that are basically uniform in seed size, uniform in color, plump, high in seed purity, high in germination rate, and free from pests and diseases.

(2) The seedling bed should be appropriately high. Choose the section of the greenhouse with the best light conditions. The bed surface should be level. Nutrient pots or soil blocks can be used for seedling raising. If conditions permit, in order to ensure a relatively high temperature in the seedbed during seedling raising, it is best to use an electrically heated hotbed for seedling raising.

(3) Water the bottom water well. Sufficient moisture after sowing is beneficial for the seedlings to emerge.

(4) After sowing, the temperature should be high to help the seedlings emerge quickly; 1 layer of plastic film can be covered over the seedbed to preserve heat and moisture, and after most of the seedlings have emerged, the plastic film is removed.

(5) After the seedlings have emerged completely, pay attention to strengthening ventilation and lowering the temperature in the greenhouse to avoid excessively high temperatures in the seedling bed, which can cause damping-off and seedling blight. (6) Watering should be done in the morning on sunny days to avoid the phenomenon of root rot caused by low temperatures.

(7) For seedling raising in nutrient pots, in order to prevent the seedlings from shading each other, the pots should be rearranged, expanding the space between nutrient pots, and at the same time the small seedlings should be moved to positions with better temperature and light conditions so that all seedlings grow uniformly.

(8) Hang reflective film to increase temperature and preserve moisture.

(9) Cover the seedbed with a small arched shed to prevent damage from cold waves.

(10) Harden the seedlings 5-7 days before planting, at 20-23 during the day, 12 at night, and 8 for short periods, to improve the adaptability of the seedlings and ensure that the seedlings have sufficient ability to resist the external environment.