Pumpkin beds are very decorative during flowering. They are decorated with large dark green leaves and large, bright yellow or orange flowers. Unfortunately, flowering does not guarantee a harvest.
Why doesn't the pumpkin set?
There are a number of reasons why a pumpkin does not set well, even if you choose a good place for the ridge and adhere to planting dates. The processes of pollination and ovary formation are influenced by:
- weather (temperature and humidity);
- care;
- lighting;
- presence of pollinating insects.
Pumpkins growing in the shade have poor quality pollen and may be sterile.This crop grows best in sunny, well-ventilated areas. At high air humidity, pollen sticks together and pollination does not occur.
Poor pollination
Pumpkin flowers have a diameter of 7 to 30 cm; they are monoecious, dioecious, and arranged solitary. It is easy to distinguish them: female flowers have pistils, and male flowers have stamens. Flowering does not last long - 1–2 days for female flowers and 1 day for male flowers.
Often the absence of ovaries is caused by the fact that there are only male flowers on the plant; this happens because the female buds have not yet formed. Bad seeds are one of the reasons why there are barren flowers on the vines. In order not to be left without a harvest, plant several varieties from different producers and choose not last year’s seeds, but 2-3 year old ones.
If there are female flowers, but the pumpkin does not set fruit, then there may be several reasons for poor pollination of the plant:
- the absence of wasps, bumblebees and bees in your garden - insects that transfer pollen from male flowers to female flowers; pollen is not carried by the wind;
- do not do formative pinching, leave all the shoots on the plant, the bush does not have enough strength to form ovaries;
- improper watering - rare in hot weather, abundant in cool weather;
- daily temperature fluctuations - above 30 °C during the day, less than 15 °C at night;
- the weather has been dry and hot for a long time;
- the plant is overfed or, conversely, lacks nutrients.
The main reasons that influence the formation of ovaries on a pumpkin are listed. Knowing them, you can help the plant not to be left without a harvest.
Excess fertilizer
Excess fertilizer is precisely the reason why pumpkin often fails to set fruit for diligent gardeners. If there is an excess of nitrogen fertilizers, the plant begins to fatten and goes into the tops.With the rapid growth of the aboveground part, the root system lags behind in development and cannot provide the nutrition necessary for fruit formation.
You diligently fertilize your beds, but the potential harvest is rapidly decreasing before your eyes, as the plant sheds ovaries and flowers. If you have prepared your garden beds well for the new season since the fall, then do not overdo it with fertilizers in the summer. What to do in this case and how to help the pumpkin? To begin, select a few of the most powerful shoots and remove the rest. Dig the stems to form additional roots, this will improve the nutrition of the bush.
Advice for the future - plant this crop in those areas where a full range of organic and mineral fertilizers were applied at least a year ago. Depleted soil also becomes the reason why fruits on pumpkins do not set well.
A lack of minerals is indicated by yellowed foliage, fallen ovaries and slowly forming fruits. In this case, mineral fertilizers containing phosphorus and potassium help. To enhance nutrition, the lashes are added dropwise.
Fruit deformity
The formation of ugly fruits on the bushes takes away the plant’s strength. For the growth of normal fruits there is not enough adequate nutrition. That is why this situation can be corrected with the help of competent formation of the bush in the same way as with empty flowers on a pumpkin.
The pattern of bush formation depends on the variety. For large-fruited varieties, after the first fruits have set, no more than 3 lashes should be left on the plant, each of them should have one ovary. The crown of the shoot is pinched at the end of June, leaving at least 4–5 leaves above the fruit.
Bushes of small- and medium-fruited varieties are formed differently. Only those lashes that have barren flowers are removed.The tops of the remaining stems are pinched off in early August, and at least 3 leaves are left above the last fruit set.
Dense foliage
Due to the too thick foliage formed on the pumpkin, the development of set fruits stops and the amount of barren flowers increases. Why this happens is clear - the plant spends all the nutrients obtained from the ground on foliage.
What can you do to help your pumpkin set fruit? This problem is usually solved using pruning shears or special lawn grass scissors. Excess leaves are cut off and sent to compost.
After cutting, the plant is fed with phosphorus-potassium fertilizers. Each lash is sprinkled with earth, after which additional roots form on it. They improve the nutrition of the bush, which accelerates the formation of fruits.
Root rotting
Pumpkin reacts poorly to summer weather: prolonged rains, temperature drops below 18 °C. The second reason for root rot is overwatering. It is necessary to inspect the plant if the pumpkin flowers and fruits fall off in such weather. Root rot can cause a plant to lack the strength to flower and bear fruit.
Signs of root rot are the same as for flower seedlings:
- in the initial stage, a yellow spot in the area of the root collar;
- at later stages there is a white coating on all above-ground parts of the pumpkin (shoots, leaves);
- underdeveloped thinned root system.
Prevention of rot is simple: abundant watering with warm water no more than once a week, in bad weather, fertilizing with urea on the leaf (1 tsp per bucket of water).Root feedings in cool weather bring little benefit, since the root system from cold soil does not absorb them well.
Keep in mind that the pumpkin needs to be watered with warm water from a barrel, and not cold water from the tap. After watering, loosen the soil shallowly so that the roots are well supplied with oxygen and excess moisture does not accumulate in the soil.
Another tip for preventing root rot is maintaining crop rotation. The cause of rot is a fungus, so you need to change the place where the pumpkin is planted every year to prevent infection from accumulating in the soil. Root vegetables, all varieties of cabbage and onions are considered good predecessors for this crop.
Hand pollinating a pumpkin
We figured out all the main reasons why pumpkins don’t set fruit well. Artificial pollination helps solve the problem in the absence of pollinating insects. Prolonged heat, the absence of apiaries near the garden - these are just a few reasons why bees and bumblebees fly little. Insects can be attracted to the garden by sprinkling pumpkin leaves and flowers with sweet water.
But it’s easier to understand the structure of female and male flowers and learn how to pollinate a pumpkin artificially. Female flowers can be easily identified by the presence of a thickening - the future ovary. Artificial pollination work is carried out in the morning.
It is necessary to select a fully opened male flower, bend back the petals, and touch the stamens of the female flower with the pestle. A positive result is achieved if the age of the female flower is no more than two days.
Some gardeners use a soft paint brush to transfer pollen. First they pass it along the pistil and then along the stamens. The fruit, with successful pollination, after some time begins to increase in size.Possible reasons why the fruits did not set after artificial pollination:
- damp weather;
- dew trapped in a bud;
- air temperature above 35 °C.
Special preparations are guaranteed to improve fruit set. For better fruit formation, pumpkin is treated with an effective remedy called Ovary. The natural origin of this biological product explains why it is absolutely safe for insects.
The drug is recommended for use in unfavorable weather conditions to stimulate the formation of ovaries. Thanks to Ovary, even in the most unfavorable weather conditions, summer residents manage grow a good harvest of pumpkins.
