Does Kale Need Full Sun?

Kale is a cruciferous vegetable that is fairly easy to grow, as long as it gets enough sun, is planted in rich, organic soil, and isn’t subjected to hot weather conditions. While you can grow kale in partial shade, the harvest will most likely be smaller. Here’s what home gardeners need to know about kale’s sunlight conditions.

How Many Hours of Sun Does Kale Need?

Kale performs best in full sun, or at least six hours of direct sunlight per day. These hours do not need to be consecutive — for instance, a site that receives three hours of morning sun, followed by midday shade, and then three hours of afternoon sun is considered to provide full sun. Because kale is a cool-season plant, it does better in summer when provided with some shade during the hottest part of the day.

• Your kale plant will grow best with 6 or more hours of sun per day.
• Kale does better in cooler temperatures and doesn’t like overly hot conditions.
• Winter-grown kale needs as much daily sunlight as possible.

If you grow kale in winter, however, you should provide the plants with as much sun as possible. Because of the angle of the earth, winter sunlight is weaker in the Northern Hemisphere than during the summer.  A winter harvest of kale tends to have a sweeter taste than kale grown in summer.

Can Kale Grow in Indirect Sunlight?

Indirect sunlight is defined as sunlight that is filtered through something before reaching the plant. In the case of outdoor gardens, this is often the canopy of deciduous trees. If you grow kale during winter when deciduous trees are bare don’t have to worry about this. Gardeners in climates with hot summers should seek a spot with indirect sunlight to grow kale. This will shield the plant against the sun’s strong midday rays. Too much heat causes kale to taste bitter. 

• Kale can be grown in indirect sunlight.
• It’s best to protect your kale plant against extreme heat from the midday sun.
• Kale can be grown indoors under the right conditions.

Indirect sunlight can also be light that passes through a window. It is possible to grow kale indoors provided the plant gets about eight hours of indirect sunlight per day. The best location for an indoor kale plant is a sunny windowsill with southern exposure.

Can Kale Grow in Shade?

Kale can perform reasonably well in shaded conditions if the plants receive at least three to four hours of sunlight per day. Partial shade and dappled shade are the best options for successfully growing kale if a garden space with full sun isn’t available. Growing kale near a white wall also provides a degree of reflected sunlight while providing light shade to your crop.

• Kale can grow in some shade.
• Light shade is best pending you can still provide your kale with three to four hours of sun.
• Avoid deep shade where your kale won’t get any sun at all.

Kale grown in partial shade will likely produce a smaller and weaker harvest than those grown with the right amount of sun.

What Happens if Kale Doesn’t Get Enough Sun?

Kale that doesn’t get the necessary amount of sunlight typically grows slowly or not at all. The plants that do grow will be spindly, pale, and won’t live as long. Overly shaded conditions are also conducive to the development of fungal diseases. These can cause significant damage to your kale plant.

• Although it’s a cold-weather plant, without adequate sunlight, kale might not grow at all.
• Too much shade and a lack of sun can promote the growth of unwanted fungal diseases.
• Kale can be grown in containers or as microgreens if you can’t provide ample sunlight in your garden.

Those who don’t have a sunny enough spot in their gardens for kale can still grow kale in containers if they move the plants to sunny spots during the course of most days. These leafy greens can also be grown as microgreens, which can be harvested in as little as two weeks.

Can Kale Get Too Much Sun?

It is entirely possible for kale to get too much sun if it’s grown in an area with warmer weather. Too much sun may cause kale to flower too early while developing an overly bitter taste. Your kale plant could also simply disintegrate and die.

• Too much sun and warm weather can negatively impact your kale crop.
• Plant your kale in autumn weather if you live in an area with extreme heat in the summer.
• Protect your kale crop if they experience heat generated from temperatures above 80°F (26°C).

However, it’s not the amount of sun that damages kale — it’s the heat generated by the sun. In areas where daytime temperatures average the high 80s or above, it’s best to plant kale during the autumn after temperatures cool down and to enjoy it as a winter crop. When temperatures average in the 70s and 80s, kale can be grown, but gardeners should provide protection from the midday sun and be sure to keep the plants well-watered.

How Much Sun Does Kale Require?

Although kale performs best when planted in a location with at least six hours of sun per day, hot weather causes kale to taste bitter and even die. Ideally, kale should be sited where it receives morning and afternoon sun but is shielded during the midday hours when the sun’s rays are strongest. Those in hot weather climates can easily grow kale as a winter crop.