These methods will definitely help your zucchini to set fruit.

A common problem when growing zucchini is the appearance of male flowers. The presence of multiple asexual flowers on the bushes causes panic among gardeners. Their concern is entirely justified, as a preponderance of male flowers leads to reduced yields, as they fail to produce fruit. If you notice many flowers on a long stalk with sharp hairs on your zucchini, then the problem of barren flowers has affected you too.

What is a barren flower?

Barren flowers on zucchini are sterile flowers that fail to develop into ovaries and, subsequently, fruit. Consequently, the harvest will be much smaller than expected. Barren flowers are not useless parts of the plant, as they are male flowers that produce pollen to fertilize female flowers, which then produce fruit. Therefore, the presence of barren flowers on a plant is a completely natural and necessary phenomenon. A problem only arises when the number of barren flowers significantly exceeds the number of female flowers. Even worse, when no female flowers form on the plant at all.

Some believe that a large number of barren flowers can seriously weaken a plant. Furthermore, they can cause disease or the infestation of pests. Many even claim that barren flowers should be ruthlessly removed. However, experience shows that such flowers quickly fade and fall off.

Reasons for the appearance of barren flowers on plants

The appearance of multiple male flowers is associated with various factors. Most often, barren flowers are caused by improper care of zucchini plants, poor weather conditions, or inadequate watering. Other causes include:

• too acidic soil;
• dense plantings;
• poor pollination;
• use of low-quality seeds;
• lack of lighting;
• development of diseases and insect damage.

If the cause of the problem is identified in time, it is possible to correct the development of plants and stimulate the formation of female flowers, and not just barren ones.

Care errors that cause barren flowers

Most often, gardeners themselves allow the emergence of an unpleasant ailment associated with abnormal flowering. The most common agricultural errors include:

1. Overwatering. Yes, zucchini love moisture, but moderation is key. If you water too often, the pollen will fall off and clump before the female flowers fully mature and form. The problem is that flowers of different sexes form at different times: male flowers first, then female flowers. To ensure a full complement of female flowers, the soil must be allowed to dry out, otherwise you'll end up with nothing but barren flowers.
2. Watering with the wrong water. To ensure proper flower formation, zucchini should be watered only with warm water, at least 16 degrees Celsius (62 degrees Fahrenheit). Cold water can cause the flowers to fail.
3. Pollination assistance. Or rather, the lack thereof. A lack of pollinating insects sometimes results in the formation of multiple barren flowers. Gardeners, unaware of the issue, fail to take steps to ensure artificial pollination. As a result, fertilization does not occur.
4. Incorrect placement of zucchini beds. In shade or densely planted areas, plants often suffer from light and nutrient deficiencies, and fruit failure occurs.
5. Excessive fertilization. Frequent nitrogen fertilization, in particular, will lead to overgrowth and a lack of fruit. Even if flowers do appear, they will be mostly undersized. Before flowering, reduce nitrogen concentrations in favor of potassium and phosphorus.
6. Bush overgrowth. If you don't pinch the growing points and remove side shoots, the plant will devote all its energy to growing unnecessary shoots, which will affect the number and quality of fruit. To stimulate the formation of female flowers and reduce the number of barren flowers, it's necessary to regularly pinch the growing points and remove side shoots.

Using the "wrong" seeds

Often, before sowing zucchini, gardeners make the fatal mistake of using young seeds for planting. In fact, older, 2-3-year-old seeds produce a better, higher-quality harvest. Young seeds are known to produce a small harvest, as plants grown from them tend to produce a large number of barren flowers. If you do use young seeds for sowing, you can improve their performance by treating them with a growth stimulant or soaking them in boiling water and heating them at a high temperature.

Poor soil quality

One of the reasons for poor plant development is unsuitable soil. Fertilizer-poor, acidic, heavy, wet, or overly dry soil all affect the health of zucchini plants. It's a known fact that female flowers fail to form in waterlogged soil. If watering isn't the issue, the soil may be overfertilized. In this case, ash and phosphorus-potassium fertilizers should be added to the soil. If the soil is too depleted, complex mineral and organic compounds should be added. Soil becomes depleted when the same plant is planted repeatedly. Therefore, the crop should be planted in a new location each time, and a different type of plant should be transplanted in the same location. If the soil is too acidic, the pH can be balanced by adding lime during autumn tillage.

Weather conditions

An overly damp, cloudy summer can result in a lot of barren flowers. Firstly, such weather is not conducive to the formation of female flowers; secondly, rain and wind distract bees from pollination. To attract pollinating insects, spray the flowers with a honey or sugar solution. If this doesn't help, artificial pollination is necessary. Avoid overwatering the soil; to achieve this, significantly reduce watering during the rainy season. If there is frequent precipitation, stretch a protective tarp over the zucchini bed. To prevent moisture from accumulating between the plants, thin out and remove side shoots. This is especially true for those planted in the shade. Frequent watering is not necessary, even on sunny days. If the nights are cool and there is heavy cold dew in the morning, warming the plants can be achieved by watering with warm water. It is also necessary to “warm” the zucchini with warm moisture at temperatures below 10 degrees and after cold rains.

Pests

Insects, eager to feast on succulent foliage, interfere with plant biological processes. This pest activity leads to an imbalance in flowering, with more and more barren flowers being produced at the expense of female flowers. Insects that cause this unpleasant phenomenon include:

• melon aphid;
• sprout fly;
• spider mite;
• whitefly and many others.

The sooner insects are detected, the faster they can be eliminated before flowering. For example, spider mites can be repelled by spraying with soap and treating with garlic infusion. Aphids can be controlled with a yarrow solution. Whiteflies can be controlled with therapeutic sprays of dandelion infusion. If folk remedies fail, biological and chemical treatments can be used, the best of which include Teppeki, Tanrek, Fitoverm, Confidor, Aktara, Actellic, and others.

Diseases

The development of infectious diseases can also cause multiple barren flowers. Diseases that contribute to this condition include:

• white rot;
• downy mildew;
• anthracnose;
• spotted mosaic.

These diseases are very difficult to treat because they develop quickly, and not every remedy can keep up with viruses, bacteria, and fungi. Pollinating insects and pests can also carry the disease. Infected seeds and dirty garden tools can also spread the disease. And, of course, many of these diseases arise from improper agricultural practices.

To eliminate harmful microflora, soil disinfection and treatment with ammonium nitrate are used. Sometimes, foliar feeding with a solution of urea, zinc sulfate, copper sulfate, and water can help combat the disease. A colloidal sulfur solution is used to treat powdery mildew. Many diseases are treated with Bordeaux mixture sprays. Fungicides can sometimes completely eliminate diseases, but most often they only delay their progression until harvest.

The most common products include Hom, Oxyhom, Abiga Peak, Strobi (used as an additive to other fungicides), Vitaros, Vectra, and others. It's important to remember that these products are only effective when used correctly according to the instructions and with repeated treatments, ending three weeks before harvest to avoid damaging the fruit. Disinfecting the seeds before planting can significantly reduce the risk of disease.

How to overcome barren flowers

What you need to do right away is stress the plants by completely cutting off watering for a few days. Even wilted foliage shouldn't bother you. However, the lack of water will stimulate the bush to develop and produce female flower buds. After 10-12 days, watering should be resumed, but be careful not to allow the soil to become too wet.

If flowering is sparse and female flowers are few in number, boron can help stimulate their formation, as this chemical element is what triggers flowering. Zucchini plants are sprayed with a boric acid solution. The solution is prepared by mixing a liter of water with 4 grams of boric acid. This therapeutic treatment instantly nourishes the plants and stimulates flower formation.

Even if there are numerous barren flowers, the situation can be salvaged manually. Pollinate the flowers yourself and then remove the empty buds from the bush. Specialized products—flowering and fruiting stimulants—will help stimulate ovary formation. You can spray the plants with a solution of "Ovary" (or "Bud," or "Tsveten").

An infusion of weeds will help boost plants' immunity and give them the strength to produce flowers of both sexes equally. To prepare this beneficial remedy, place the mown grass in a barrel of water and let it steep for a couple of weeks. Then dilute the concentrate with warm water and water the zucchini.

Zucchini thrive on warmth, and cold nights have a severe negative impact on their growth. Therefore, when temperatures drop, cover the bed with lutrasil.

How to prevent the appearance of barren flowers

The number of empty flowers on plants can be controlled through proper agricultural practices. To reduce the number of empty flowers, the following measures should be taken:

• store and select seeds correctly;
• attract pollinating insects;
• place the beds with zucchini on fertile, well-fertilized soil;
• during the growth process of seedlings, treat them with growth stimulants;
• Water zucchini only with warm water, applied to the base of the plant. Avoid allowing moisture to come into contact with the leaves and flowers, as this can cause pollen to stick together.
• create a comfortable microclimate for the proper development of plants;
• Regularly treat the area with fungicides and insecticides.

Advice from the pros

Since zucchini produces a lot of empty flowers in high humidity, it's recommended not to grow this crop under plastic or in a greenhouse. Plants need to breathe and be pollinated regularly. Insects rarely enter a greenhouse, so pollination may not occur at all. This can result in a lot of empty flowers.

Proper seed storage affects the quality of flowering. They should not be frozen or stored in cold places.

When planning your garden bed, keep in mind that zucchini prefers light partial shade. Therefore, plant them in open, eastern-facing areas. In hot weather, provide shade. However, don't allow the plant to be deprived of sunlight, as it's the sun that allows the female flowers to develop.

When planting zucchini, it's important to maintain optimal spacing between plants. This should be 35-45 centimeters. If you plant them too close together, they will shade each other as they grow, and moisture will accumulate in their thicket. If you planted zucchini too close together, you'll need to thin them out early in the growth process.

Plants expend a lot of energy on their foliage. If the bushes have grown too large and are creating shade, you need to remove unwanted leaves—lower ones and damaged ones.

Conclusion

A large number of barren flowers shouldn't alarm a gardener. While this is an unpleasant phenomenon, it's still possible to get a fairly good harvest. The key is to promptly identify the cause and adjust the growing conditions. Rush to remove male flowers, as this can disrupt pollination and prevent the plant from forming fruit.