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Zucchini rot at the top: what are the causes & what you can do preventive and after-effective

There are certain vegetables that are not only delicious, but also so easy to cultivate that just about everyone should have them in the garden and especially beginners should try their hand at them. Zucchini is undoubtedly one of them. If you, too, have decided to grow the vegetable, you should, in addition to the usual care, regularly check them for diseases and pests, so as to avoid their spread, if possible, or still save the affected plant itself. Or maybe you have already noticed something? If your zucchini is rotting, you should take immediate action to still be able to save all the other fruits.

Why rot zucchini in the garden?

Zucchini rot at the top - The causes and what to do

First of all, at the outset, if the ends rot on zucchini, it does not necessarily mean that you did something wrong. Not always the wrong care is the cause of a bad harvest, sometimes you just can not help it. But why do zucchini rot at the top?

Usually, the weather is to blame for this problem. For this reason, the risk of this rot is not every year. Certain weather conditions change the composition of the soil, making it somewhat difficult for the plants (and you). Nevertheless, you should also reconsider your care measures . The following list will show you the reasons for rotting fruit.

Calcium deficiency causes zucchini fruit to spoil while still on the plant

Why does my zucchini rot on the plant?

  • Incorrect fertilizing: Calcium deficiency or an over-fertilization especially with nitrogen.
  • unfavorable temperatures: over 30 degrees as well as cold weather or low temperatures in combination with humid climate favor rot, as well as high temperature fluctuations between day and night
  • little sunlight
  • unfavorable soil conditions: Waterlogging and inadequate aeration.
  • excess of fruit, which causes some of them to die off
  • poor pollination
  • zucchini diseases such as blossom end rot.

Zucchini rot at the top – what are your options?

Provide rain protection during prolonged periods of rain

The good news is that, on the one hand, you can take preventative measures to keep rot from occurring in the first place. On the other hand, if the problem has already arrived, you can take action and save all the other fruits.

Preventive measures against rot on the fruit

Mulching keeps plants moist but delicate fruit dry


To act preventively with regard to weather conditions seems simply impossible at first. However, in fact, with regard to the location, for example, you can ensure that the plants are less affected by the influences. Also, you can follow the forecasts and protect the plants if necessary.

Zucchini rot when it is very hot - Provide sun protection.

Protection from the weather:

  • Above all, it is important that the zucchini plants get enough sun. This will help them dry faster if they do get exposed to dew, rain or other types of wetness, and will also allow them to develop better and stronger.
  • If the region in which you live is generally cooler in the summer than other regions, it is also advisable to choose a location that is protected from the wind.
  • In this regard, a place in front of a house wall or wall is considered particularly advantageous. These are heated by the sun during the day and release this collected heat at night. Of course, they also warm the plants, so you can counteract larger temperature differences between day and night in this way.
  • You can block out excessively high temperatures with shade. You don’t necessarily need to build a canopy for this. Choose a larger tree in your garden. However, you should make sure that the plants still get enough sunlight, because as already mentioned, the lack of sunlight also causes the zucchini to rot.
  • Too much moisture during longer periods of rain, on the other hand, can be bridged with the help of a rain cover. Here, however, be sure to ensure that good ventilation is still guaranteed. For this purpose, there should be a distance of at least 20 cm between the protection and the plants.

Zucchini rot if you do not fertilize properly - use compost.


Prepare the soil properly:

  • Even before planting the zucchini plants, loosen the soil well to ensure adequate aeration.
  • Mix in compost . This will provide you with a high-quality slow-release fertilizer that will supply the plant with everything it needs until flowering, thus avoiding accidental overfertilization.
  • If the soil in your garden is very clayey and tends to prevent good aeration, you can work it up with sand and make it more permeable.
  • A layer of mulch is beneficial to keep the plants themselves moist, but at the same time protects the fruit from moisture, as this, in turn, would harm them. This way, the zucchini rests on the mulch layer and is not in direct contact with the moist soil.

What to do if zucchini rot?

Zucchini rots due to poor weather conditions

Have your fruits already started to develop rot on the top? Immediately dispose of the affected fruits, because they can not be saved. But all the others are. Immediately provide them with calcium and stop other fertilizing. Nowadays, many tend to take too good care of their plants and harm them with an excess of nutrients. In fact, some nutrients in excessive concentrations prevent plants from absorbing enough calcium. These include ammonium, potassium and magnesium. Sufficient (but not too much!) water is also important for good calcium uptake. A calcium deficiency then just ensures that the top of the zucchini will rot.

Plant care to prevent rot on fruit - how to make harvest a success

By taking these measures, you can also stop blossom end rot, which is caused by a lack of calcium, among other things, and causes the fruit to rot at the tip. So if your zucchini rots after flowering, this could be a cause that you should do something about right away.

Plant and care for zucchini plants properly to prevent rotting