Basil thrives in the summer when it can get direct sunlight. It is commonly known that basil needs a lot of it to thrive, but can it actually get too much?
Basil plants need a lot of sunlight but can also get too much. As a general rule, basil should get between 6-8 hours of direct sunlight per day but it depends on several factors. In spring and fall, it can survive more sun than in the summer.
Keep reading to learn how much direct sunlight is too much for your basil and what some of the signs that your basil is getting too much sun are.
Signs Basil Plants Are Getting Too Much Sunlight
Yellowing leaves and wilting
The first sign that your basil is getting too much sun is that the leaves will begin to turn yellow or even brown and dry out. In addition to that, the plant will start to wilt which is a mechanism plants use to reduce the amount of sunlight it absorbs.
Wilting essentially means that the leaves begin to droop and hang much looser than usual. They will become soft and begin the fold to reduce the overall surface area and thereby reduce the amount of direct sunlight that reaches them.
If the sun is too intense and hits basil for too long, it can cause the upper leaves to be scorched and become dark and dry. Young plants are more fragile than older plants and are more likely to take severe damage from being exposed to too intense sunlight for too long.
That is most likely what happened to my basil plant in this photo.
To prevent this issue, I recommend that you move your basil out of direct sunlight in the afternoon when the sun is most intense and then back to its original place after a few hours (read more about why morning and afternoon sun matters here).
Basil has thin leaves that do not contain as much water as many other plants’ leaves so when basil is exposed to direct sunlight for too long, the water in the leaves will evaporate faster than the plant can obtain water from the soil and the plant will begin to wilt to reduce the amount of sun it absorbs.
How much direct sunlight your basil should get also depends on where you grow it.
If you are growing basil indoors by a window, it can get more direct sunlight than if you are growing it in a greenhouse. This is because the temperatures in greenhouses can get much higher than indoors and since the glass in greenhouses rarely has UV-filtering which most glass used for windows do.
What Happens if Basil Does Not Get enough Sun?
If basil plants do not get enough sun, they adjust by growing slower and producing fewer, smaller leaves to better match the amount of energy they can absorb from the sunlight. In addition to that, the plants will stretch and become leggy in an attempt to reach a height where they can receive more sunlight.
Basil plants are excellent at adjusting their growth to the specific conditions they are given and the more direct sunlight they receive, the faster they grow and the more leaves they will produce.
If basil does not get enough sunlight, however, it acts completely opposite.
The photo above is a perfect example of how it looks when basil is getting too little sun compared to how it looks when it gets enough.
Both plants in the photo are my own and while they are both young, it is already easy to see that the plant on the right has been growing in more sunlight than the plant on the left since the leaves are much denser and not placed nearly as far apart as they are on the left plant.
The two plants were growing in different places so I solved the issue by just moving the left plant which had become stretched and leggy to the same place as the other plant which was doing great all along.
Read My Complete Guide to Growing and Caring for Basil
I have written a thorough guide where I cover all parts of growing your own basil including choosing a variety, sowing the seeds, the best growing conditions, pruning, propagation, harvesting, storing, solving various problems, and a lot more. You can find the article on this link.