Have you ever wondered ‘why are my cucumbers turning yellow?’ Well, I have some answers for you. Cucumbers are a popular garden vegetable perfect for summer. They are cool and crisp with a mild flavor that is a great addition to a salad or in homemade sauces like tzatziki.
Part of the joy of growing your own vegetables is watching your plants bloom and fruit and then reaping the rewards of your labor. So it’s disappointing when you find that your effort has gone to waste because your cucumbers are turning yellow and don’t look very appetizing. If you’ve ever experienced the disappointment of yellow cucumbers, there is plenty that you can do to prevent it from happening again. Let’s find out the reasons why your cucumbers are turning yellow.
1. Cucumbers Over-Ripening
The most common reason for yellow cucumbers is simply over-ripening. Most cucumbers are ready to harvest when they are deep to bright green, depending on the variety. Cucumbers are fast growers and most varieties are ready to harvest 50-70 days after planting. It’s tempting to leave them on the vine to increase in size. But when they start to get too big, the flesh becomes soft, the taste becomes bitter and the skin becomes tough and turns yellow. Cucumbers are best picked while they are still immature before there is any indication of yellowing. For slicing cucumbers, this will be at about 8 inches. For pickling cucumbers, harvest them much earlier. Since the fruit ripens at different times, plan to pick cucumbers every day or two to avoid leaving them on the vine too long. Other benefits of harvesting your cucumbers earlier are:
- They are less bitter
- They are crisper
- They have better nutritional value
- It encourages new flower growth
2. Poor Soil Quality for Growing Cucumbers
If it appears that your cucumbers are turning yellow early and they also appear stunted, you may have poor soil quality. Cucumbers are generally very tolerant of various soil qualities, but they do require nutrients from the soil to thrive. If you’ve been growing cucumbers in the same area for more than two years and have noticed that the quality of the fruit has decreased, it’s likely due to low soil quality. Here are some ways you can improve your soil:
- Rotate crops – Planting the same crops in the same location year after year will deplete the soil of the nutrients that the crop needs the most. Rotating crops helps preserve soil quality.
- Add compost – Compost adds nutrients to the soil.
- Add fertilizer – Fertilizer, like 10-10-10, adds nutrients to the soil. Try this organic vegetable fertilizer here.
3. Inconsistent Watering of Cucumber Plants
Cucumber plants have shallow root systems and are sensitive to inconsistent watering. They thrive when the soil remains slightly damp. Water cucumber plants twice a week with 1-2 inches (25-50mm) of water, or any time the top inch of soil feels dry to the touch.
If there has been rain, water cucumber plants less. And during fruit formation, water can be increased to around a gallon (3.7lt) throughout the week.
It’s a good idea to keep an eye on the soil drainage. If you have poor drainage and the roots stay too wet, your cucumber plants are at risk of fungal or bacterial diseases, such as root rot.
If you are unsure about the soil moisture you can monitor it with a watering gauge here.
4. Cucmber Plant Disease and Pests
Plant diseases can decrease the quality of your cucumber plants and even destroy your crop completely. If you recognize the symptoms early, you can remove the affected plants before the disease spreads.
- Cucumber Mosaic Virus (CMV) – This disease causes the cucumber fruit to turn pale and bumpy and the leaves to be mottled with yellow spots. The disease is spread by aphids and can contaminate tomatoes and pepper as well as cucumbers so get rid of any diseased plants as soon as you notice symptoms. Fortunately, CMV does not pass to the seeds or remain in the soil. Using floating row covers can minimize the risk of the disease, but they need to be removed when the plant starts to bloom to allow for pollination.
- Cucumber Beetles – The larvae of this insect feed on the roots of the plant while the adults will eat the leaves, flowers, and fruit causing bacterial wilt. As with CMV, using floating row covers can help minimize risk. Remove infected plants early before the beetles can spread the disease. The use of horticultural neem oil, sticky paper and trap crops can also help minimize cucumber beetles in your garden.
5. Yellow Cucumber Varieties
The final reason that your cucumbers are yellow is that you have a yellow variety. Double-check your seed pack or your nursery label to see what variety you are growing. Here are just a few of the edible yellow cucumber varieties available:
- Lemon Cucumber – round and yellow like a lemon when it is ready to harvest and has a mild, sweet flavor.
- Chinese Yellow Cucumber – oval and dark yellow when it is ready to harvest and has a mild, sweet flavor.
- Crystal Apple Cucumber – a pale yellow to white greenish fruit, oblong in shape with a sweet, mild flavor.
- Dosakai Cucumber – small, long, and mostly yellow with hints of orange and green; it has a mild, tart flavor.
Is it safe to eat yellow cucumbers?
The short answer is… it depends. If your cucumber plants were diseased, you will have to discard them. If you are growing an edible yellow variety, they are safe to eat and are normally a yellow color. If your green cucumbers were left on the vine a little too long and have started to turn yellow, you can still eat them, but the skin will be tough and the taste will be bitter. They may not be the best to slice into a salad or eat by themselves, but you could add them to a recipe, such as a relish, where a little bitterness will have minimal effect on the final dish. If the cucumbers are so over-ripe that they are turning orange and soft, it is best not to eat them.
What else can I do with yellow cucumbers?
For cucumbers that are yellow simply because they are over-ripe, you can use them for seeds to replant next season. You can also use them for composting which will be beneficial for your garden no matter what you plant next season.
Don’t be disappointed by yellow cucumbers again. If you find yellow cucumbers in your garden, determine the cause and take corrective action. That might be pest control, careful watering, or simply harvesting earlier. Before you know it, you’ll be growing crisp, green cucumbers like a pro.