The zucchini is one of the most popular plants that people like to grow at home. It’s a summer squash that grows around one meter in length, though it’s harvested much earlier.
Zucchini is commonly used in a variety of different recipes and if you want to consume only healthy and organic vegetables, you should consider planting them at home.
However, you should know that not every person who plants the zucchini in their garden is able to get a big harvest.
In some cases, you will end up losing out a significant part of your harvest as the midsummer arrives. You might notice that the plant is green and leafy, and even produces flowers, though the zucchini might be turning yellow.
In some cases, it might wither and even drop from the plant outright. While there is absolutely no way to reverse the yellowing, you should know that there are ways to prevent this from happening.
Many people who like to grow zucchini are often disturbed and disappointed that despite taking so much care about their plants, they are unable to get a good harvest.
Before you focus on the reasons for the zucchini yellowing, let’s talk about the biology of the zucchini plant.
The Biology
Zucchini grows primarily on bushy plants, and they produce male and female flowers.
The male tends to blossom, and you can find these flowers on the long and slender stems. These are used to pollinate the female flowers, which you will find on the shorter and swollen stems. The female flowers then develop into the zucchini fruit.
If the male or the female flower does not blossom at the same time, or if the bees intervene, you will get relatively poor pollination. For instance, if there is a bit of rain or high winds in your area, the pollination will reduce dramatically.
Similarly, if the temperatures rise considerably or fall drastically, the pollination won’t be as good.
There are several symptoms of poor pollination that you should look for. Plants that are not properly pollinated will usually develop less fruit, and you will notice that the zucchini turns yellow and will drop prematurely.
In the world of horticulture, this is known as fruit abortion.
In some cases, the zucchini will be stunted and may be misshaped. You will notice that the yellowing will usually occur from the end of the fruit (where it blossoms from) and then moves down toward the stem.
There are several reasons why your zucchini might be turning yellow (apart from the pollination reason). In some cases, the zucchini leaves might be turning yellow as well.
Here are just a few reasons why your zucchini might be turning yellow.
Reasons for Zucchini Turning Yellow
1 – Cucumber Mosaic Virus
The cucumber mosaic virus is one of the most common diseases that plants might succumb to. It is caused by the presence of insect pests.
As the name suggests, the cucumber mosaic virus also affects cucumbers in the same family. The first signs of the disease include yellowing leaves of the zucchini plant, along with the veins.
This is caused due to the aphids which start to feed on the underside of the leaves. The virus is transmitted through these tiny insects which leads to stunted growth as well as relatively poor development of fruit.
Once the plant gets infected, you should know that there is no definitive cure for it.
If you notice the plant infection, you can limit the spread by cutting off the affected parts of the plant. If you notice any signs of aphids, you can make use of neem oil as well as insecticidal soap.
Even then, the best solution is to just remove the infected parts.
2 – Spider Mites
Another very common pest that is going to affect your plants is the spider mite. The spider mite usually sucks the sap from the leaves of the zucchini plant.
Again, you will notice that the leaves will start to turn yellow first, and then it’s going to slowly spread toward the fruit as well, which is going to break off and fall prematurely to the ground.
Thankfully though, there’s a cure for the spider mites. The best way to get rid of these mites is to treat the plant with an insecticidal soap. Create a mixture and spray it all over the leaves.
These tiny mites know how to hide properly and you are going to face quite a bit of difficulty in getting rid of them properly.
That is why you need to make sure that all exposed surfaces are covered with the insecticidal soap. If you want, you can put up some attractions for lacewings or ladybugs.
They love feasting on the spider mites, and it won’t be long before the entire population is cleaned out from your plants.
3 – The Fusarium Wilt
The zucchini plants can also be affected by the Fusarium wilt. This is a fungal disease that tends to affect the vascular tissue of the plant.
Cucumber beetles are usually responsible for carrying the spores that are found in the soil into the plant. Even though cucumber beetles primarily feast on cucumbers, there are a few who don’t care about this, and are just as attracted to the zucchini.
Keep in mind that once the plant is infected, there is no way to cure it. Fungicides are going to be completely ineffective in these cases. The only thing that you can do is to remove the damaged plants and clean the area. It’s best to turn the soil as well.
If you want to make sure that your plant does not get so easily infected, you should consider planting the disease resistant variants. There are quite a few varieties available, so it’s best to talk to your local plant nursery owner or a horticulture specialist.
You will need to make sure that the plant gets its intake of nutrients, and you will have to regularly water the zucchini plants as well.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.