Can Cucumber Plants Get Too Much Sun?

All plants need sunlight to grow and thrive, and cucumbers are no exception. In fact, cucumbers are sun-lovers. However, if you’re just getting started growing cucumbers or already have some in your vegetable garden, you may be wondering whether you can expose them to too much sun.

Cucumber plants can get too much sun. Although cucumbers grow well under a lot of sun, sometimes the intense sunlight can be too much for them. Under such conditions, cucumber plants experience wilting, leaf dropping, leaf scorching, premature ripening, and in extreme cases, stunted growth.

Keep reading this article to learn more about cucumber plants and sunlight, including how many hours of sunlight they need, whether they can grow in the shade and how to protect these healthy veggies from excessive sun and heat.

Do Cucumbers Need Too Much Sun?

Here’s what research shows.

Cucumbers need full sun, and they do well when they get eight to ten hours of sunlight per day, according to a report by the University of Maryland Extension. Full sun means direct sunlight that is not obstructed by shade from shrubs, nearby plants, and trees.

With an optimal amount of sunlight, cucumbers grow well, mature on time, and produce high yields.

However, too much sun can sometimes be harmful, especially during dry spells. As discussed, excessive heat from the sun causes mild to severe health and yield issues with your cucumber plants.

So, for better yields, you should ensure your cucumber plants get an optimal amount of heat and sunlight. 

How Much Heat Can Cucumber Plants Tolerate?

Cucumber seeds need temperatures between 60 – 90 °F (15.6 – 32.2 °C) for them to germinate. The warmer the temperatures, the faster the seeds will germinate, taking around three to ten days. After germination, cucumber plants can tolerate temperatures between 65 – 75 °F (18.3 – 23.9 °C).

Why Do Cucumber Plants Wilt in the Sun?

Wilting in cucumber plants is mainly a sign of exposure to too much sun. However, it can also occur in cucumber transplants that have been recently moved from an indoor to an outdoor setting. That is why you have to acclimate your indoor cucumber plants before moving them outdoors.

Allow your indoor cucumber plants to adjust to direct sunlight by letting them sit under the morning sun–ideally between 8 AM and 12 PM–for an hour or two, gradually increasing it by an hour every day for a week.

However, if you spot wilting in your cucumber plants, delay moving them outdoors for another week and water them more frequently.

How Much Water Do Cucumbers Need?

Like any other plant, water is a basic need for the healthy growth of cucumbers.

Cucumber plants need at least 1 – 2 inches (2.54 – 5.08 cm) of water per week, depending on the prevailing weather conditions. And to keep the water from evaporating under too much sun, add a little mulch!

Do Cucumber Plants Like Morning or Evening Sun?

Cucumber plants will do well when exposed to sunlight at any time of the day, whether morning, noon, or evening. However, if you have to choose your exposure time, go for the late morning or afternoon sun. This is because the sun’s rays are more intense during these hours.

According to a recent report by the United States Environmental Protection Agency (EPA), sun rays are strongest between 10 a.m and 4 p.m. So, ensure you take advantage of this time bracket to give your cucumber plants as much sun exposure as possible.

However, also remember that cucumber plants may not be able to tolerate too much heat. It is best to consider the temperature before letting your plants bathe under intense sunlight.

Cucumbers Affected by Too Much Sun

Although cucumber plants do well under plenty of sunlight sometimes, the sun rays can be too much for these healthy, crunchy veggies to handle. Excessive sun mainly affects cucumber transplants and some already established plants. Let’s look at these in detail:

Cucumber Transplants

If you start your cucumber seeds in an indoor space, it’s advisable to harden them before transferring them outdoors. Hardening means gradually exposing the young cucumber plants to the sunlight and other outdoor conditions. Doing this for a few hours each day helps the plants adjust to the new environment.

However, suppose you skip the hardening part and expose your growing cucumber plants to excessive sunlight all at once. In that case, they’re likely to experience leaf scorching, wilting, leaf dropping, and stunted growth. In extreme cases, the growth may stop altogether!

Established Cucumber Plants

Excessive sun can also affect already established cucumber plants. In this case, the effects will be evident in the yield. So, besides leaf burning, the cucumber plants will experience premature ripening and reduced produce.

This excessive sun exposure can be caused by different factors such as:

  • Diseases: Some cucumber plant diseases such as bacterial wilt and powdery mildew destroy the leaves leaving the plant and fruits exposed to too much sun.
  • Pests: Pests such as cucumber beetles and aphids attack the leaves of cucumber plants leading to excessive sun exposure.
  • Poor pruning: If you’re not careful when pruning, you may end up removing a lot of the top leaves, thus exposing your plant to too much sun.

How To Protect Cucumbers From Excessive Sun

Too much of anything is dangerous, which also applies to cucumber plants and sunlight. Too much sun can be harmful to them!

When the sun is too much for the cucumber plants, their yield decreases. Also, the rate of moisture evaporation from the soil increases, which leaves your plants with inadequate moisture. Cucumbers grown with insufficient moisture produce poor tasting or oddly shaped fruits.

So, to get high-quality produce from your cucumbers, you should learn how to protect them from excessive sun.

And the best way to shield cucumber plants from the effects of too much sun is through shading. Outlined below are the top ways you can protect your cucumbers from the effects of excessive sun exposure:

Build a Shade Structure

One of the tricks you can use here is building a simple DIY shade structure such as a pergola or an arbor. A simple shade structure is enough to provide enough shade for your cucumber plants but always keep an eye on vining plants that grow all over the structure blocking even more sunlight.

Your aim should be to offer just a little shade enough for the plants to grow and yield well because, under excessive shade, your cucumber plants will only bear long leaves with tiny cucumber fruits.

Use a Shade Cloth

You can also get a shade cloth or umbrella and use it to cover your cucumber plants. This method is as simple as draping a piece of cloth over the cage or trellis housing your cucumber plants.

The shade cloth blocks some sunlight and lowers temperatures slightly, creating optimal conditions for the cucumbers to thrive. Your choice of shade cloth will depend on the amount of shade you want to create.

Prune Carefully

While it’s advisable to prune cucumber plants, especially the lower leaves to prevent diseases from splashing on the soil during the rainy season, you should be careful not to remove the top leaves.

Removing many of the top leaves exposes the plant and its fruits to too much sun. So, always be careful with your pruning.

Plant Disease-Resistant Cucumber Varieties

Another way of protecting cucumber plants from too much sun is by planting disease and pest-resistant varieties. Consider investing in quality seeds that can withstand pest and disease attacks.

Such plants remain healthy at all times, meaning they’ll have a strong root system and plenty of healthy leaves. Strong roots help the plant find water even during the dry season, while the leaves reduce excessive sun exposure.

Practise Mulching

Mulching is an ideal way to reduce the soil’s moisture evaporation when plants are exposed to too much sun. With reduced evaporation, cucumber plants will have enough water to help them grow and thrive under excessive sun.

You can use simple mulch such as compost, dried leaves, straw, or shredded newspapers when mulching your cucumber plants. One-inch thick mulch is enough to keep your cucumber plants safe from the adverse effects of too much sun.

Water Your Plants Regularly

Watering is another common way of protecting plants from excessive sun and heat. Watering your plants regularly ensures they get enough moisture to grow and produce quality cucumbers.

Avoid overhead watering because this could destroy the fruits when watering your plants. Instead, you should keep the soil moist by watering around the base of the plant.

Also, you should be careful not to overwater your plants. At least one inch (2.54 cm) of water per week or slightly more is enough for cucumber plants. The common sign of overwatering in cucumber plants is leaf yellowing.

If you feel that the sun is too much, add a little mulch around your watered plants to help them retain moisture longer.

Can Cucumbers Grow in the Shade?

Cucumber plants can grow in partial shade, but they won’t give you the best produce. So, if the only space you have available to grow your cucumbers is shaded, such as an indoor space, ensure you supplement full sunlight with the right artificial light, such as full-spectrum fluorescent grow lights.

You can also prune nearby trees and shrubs to ensure your cucumbers get optimal sunlight.

Conclusion

Whether you enjoy your cucumbers raw in salads or sautéed, growing these crunchy veggies is the best way to ensure you enjoy a healthy bite anytime you want.

To get the most out of your cucumbers, you need enough knowledge of their optimal growth condition.

Despite cucumbers being sun lovers, you should ensure they get only the optimal sunlight because too much of it can damage them. Ideally, 8-10 hours of intense sunlight per day are ideal for cucumber plants to grow well.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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