The idea of frolicking into the garden to pick some fresh lettuce for a delicious salad is one we all harbor. Making sure you do have lettuces at all means making sure they grow healthily and don’t burn in the sun.
Lettuces need full sun to grow best, which means 5 to 6 hours minimum a day, and up to 9 or 10 if possible. In warmer areas, it’s best to provide some shade for lettuce plants for some hours of the day. Lettuces can grow in the shade, but will still need bright light.
Read on to understand more about lettuce and its relationship with the sun.
See our trick for harvesting lettuce all year long.
Does lettuce need full sun?
Lettuces can grow in the shade without direct sunlight. However, they do best in the full sun, so they do need it to produce the best crop. However, full sun can mean high temperatures, which lettuces don’t tolerate well.
Lettuces need full sun to grow best, although they can grow in the shade.
This means that they really should grow in full sun if possible, partly because they are a cool season crop.
However, it’s also because they need as much light as possible to produce enough energy to grow.
Full sun means warmer temperatures and lettuce doesn’t tolerate high temperatures very well.
What it comes down to is that if the temperatures in your area aren’t very high, then the lettuces need full sun.
If you live in an area where the temperatures really soar, even in early spring, then your lettuces will need bright light, but not necessarily full sun.
How many hours of sun does lettuce need?
To grow quickly and produce a good crop, lettuces need at least 5 and up to 9 hours of sun a day. If giving them this much sun means they are exposed to very high temperatures, then they can grow in partial shade, as long as they still get enough light.
Lettuce plants need at least 5 – 6 hours of sun a day.
However, they really do need as much sunlight as possible, which means the ideal is about 9 – 10 hours.
During the hotter hours of the day the shade will protect them from high.
This means planting your lettuces in a position that gets sun until late morning and then becomes shaded, as the sun moves over.
You also need to consider how much sun the lettuce plants need during their growth cycle.
If lettuce is grown towards the middle of summer, it may be exposed to too much hot, ongoing light.
This can cause the plants to bolt, which is producing longer stalks that go to seed.
In warmer areas, this can be avoided by planting varieties that are more heat resistant and may take a long time to bolt.
Lettuce seeds need warm soil and a long supply of good light to germinate.
They should be planted in soil that can be heated by the sun, but they should not get too hot.
If germinating seeds and seedlings get too hot, they can be damaged.
It is often more productive to germinate the seedlings inside, where you can control the amount of light and the temperature more easily.
It is possible to use bright lights inside to mimic the sunlight, but also to prolong the amount of light, if necessary.
Check out our complete guide to growing lettuce hydroponically.
Can I grow lettuce in the shade?
Lettuces can grow in the shade, particularly if it is quite filtered and not solid. However, they do far better in the sun and can grow quite slowly when sheltered. What shade does offer lettuces is protection from harmful high temperatures.
The key to growing lettuces successfully is to make sure they get enough light, which can be direct sunlight.
Because they are a cool season crop, lettuces can be sensitive to high temperatures.
In hot locations, it is useful for lettuces to be grown in the shade, but the yield may not be so good.
The key to growing lettuces in the shade is to make sure they receive enough bright light.
This can mean planting them in filtered shade.
If you live in an area with a generally warmer temperature, even in spring, you should definitely grow the lettuces in the shade.
You can also choose your lettuces carefully, because there are cultivars that tolerate the heat better than others and can even grow well in the shade.
Read the full article about heat tolerant lettuce.
Do lettuce like full sun or shade?
Lettuces like full sun rather than shade, because that is where they grow fastest and best. However, they also don’t like high temperatures. More than full sun, then, lettuces light enough bright light and a temperature they can tolerate.
Put simply, the more sunlight your lettuces get, the better they will grow.
This must mean that they prefer full sun to shade.
To make it a little more complicated, though, lettuces are sensitive to temperatures and can be affected by the high temperatures associated with a lot of direct sunlight.
The best solution may be to grow lettuces in the shade, but still make sure whatever light they get is still quite bright.
Again, it is not quite so easy, because lettuces grow at a slower rate in the shade than in the sun.
To get the best lettuce crop, without damaging the plants, it’s about balance.
You need to get the best balance between the most bright sunlight possible for the plants and ensuring they don’t get too hot.
A lot of this depends on where you live.
The bottom line is if you live somewhere with a warm to hot climate, then the lettuces will most likely do better in the shade, or at the very least in the shade during the hottest part of the day.
If you live in a cooler area, then your lettuces will need and like full sun, rather than shade.
See what temperatures lettuce can tolerate.
Can lettuce plants get too much sun?
Lettuces love sunlight and do best in full sun. However, they also don’t do well in high temperatures. If the sun is very hot, then they can get too much sun, which can burn the leaves and will cause the plants to wilt.
It’s not so much a question of lettuces getting too much of the sun itself, but getting too much of what comes with the sun: the heat.
Lettuces like the sun and grow best in direct sunlight.
However, they don’t like hot temperatures, because they are a cool season crop.
If a lettuce plant can get sun just about the whole day and not become too hot, this is the first prize.
This is why lettuces must be planted early in the spring, so that they grow as the weather is warming up, not when it is warm and will only become hotter.
If a lettuce plant regularly gets too much sun, it may bolt early.
The energy will go into producing long stalks which will flower.
The growing season is then over.
Another effect of too much very hot sun is that the lettuce leaves will wilt and eventually dry out.
Generally, sunburned leaves don’t recover, so you’ll have to remove them and look after the rest of the plant very carefully.
See the best heat-tolerant lettuce varieties.
Conclusion
Lettuces need a lot of sun to grow well, which means at least 6 hours a day, but preferably closer to 9 or 10.
If this means they will be exposed to very high temperatures that could harm them, then rather grow your lettuces in the shade.
A win-win situation is for them to get full sun during the cooler time of day and partial shade when the sun really beats down.
