7 Reasons Why Lemon Trees Grow Best In Full Sun

Lemon trees are a beautiful addition to the yard with attractive white blooms and sour fruit that can be used in a variety of dishes. Luckily for us, lemon trees are relatively easy to take care of, but one thing that lemon trees definitely need to thrive is lots and lots of sun.

Lemon trees grow best in full sun because it will help the tree grow faster and establish stronger roots. Full sun conditions will yield more fruit and the fruit will taste better. Sunny conditions also help the tree flower, provide extra warmth, and keep the tree nourished.

If you’re considering growing a lemon tree in the yard, read on to discover all the reasons why planting them in full sun will give you the best tree with the tastiest fruit!

Lemon Trees Need Sun To Grow!

Trees in general cannot be planted just anywhere. Every tree has a preference for the region, soil type, water conditions, and sun conditions.

Lemon trees require a little work, but when they’re sprouting fruit that you can use in pies, dishes, and beverages, it will all be worth it.

In the United States, most lemon trees are grown in subtropical areas like Florida and California. Some can survive in southern Texas as well. Lemon trees are typically more cold-sensitive than most other citrus trees.

When it comes to growing these amazing trees in your yard, you’ll want to take into consideration the soil and climate, but most importantly, you’ll want to make sure you’re giving your lemon tree enough sun.

Something to note as a fun fact – lemon trees are actually evergreen and keep their foliage year round!

Lemon Trees Grow Faster In Full Sun

Sunlight is important for all life, including lemon trees. Without sunlight, lemon trees would not have the energy to grow tall, bloom flowers, or produce fruit. 

One of the amazing things that sunlight does for lemon trees is provide them with energy to begin the process of photosynthesis.

Photosynthesis Takes Energy From The Sun 

Photosynthesis is the process of converting water and carbon dioxide using the energy obtained from the sun. The water and carbon dioxide are then transformed into sugars that the lemon tree uses to grow leaves, stems, roots, you name it!

In other words, the sun is what helps feed lemon trees. The more sun, the more food. The more food, the more growth.

Lemon trees do not use their food solely to grow. They must divert energy to the roots, flowers, fruits, and new growth. When Lemon trees aren’t exposed to enough sun, they cannot divert as much plant food into new growth and the tree will not grow as fast.

Full Sunlight Helps Lemon Trees Bloom

Similar to how sunlight helps a lemon tree grow faster, sunlight also helps lemon trees to bloom fuller and with better color.

When lemon trees are grown in full sun, the tree has more energy to divert into things like flower and fruit production.

If grown in partial shade, blooms may be delayed and the flower color may be a dull cream color instead of their usual fresh white.

Lemon Trees Yield More Fruit In Full Sun

Lemon trees aren’t normally planted simply for their shape, shade, or pretty flowers. They’re planted because a homeowner wants to harvest the lemons.

To get the most lemons out of your lemon tree, you’ll want to plant it in full sun. Sunny conditions promote higher fruit production and the fruit will usually be fuller.

According to research published in the Journal of Horticultural Science, shade led to smaller lemons (less overall weight and width) as opposed to full sun in regards to overall fruit production. Essentially, this led to less yield come harvest time since the lemons were much smaller.

Basically, just make sure to get your lemon tree as much sunlight as possible to have the fullest lemon you can get!

Full Sunlight Helps Keep Lemon Trees Warm

Lemon trees are very sensitive to cold weather. They are used to living in warm tropical, subtropical, and Mediterranean-type climates.

When grown in full sun, temperature drops are less noticeable and the lemon tree is less likely to become damaged during a prolonged period of cold temperatures.

Temperatures do not need to be exceedingly low for lemon trees to get damaged. Temps around 31℉ and lower are enough to harm a lemon tree if they are exposed to it for long periods.

Most US variety lemon trees are cold hardy to zones 9-11, meaning they benefit from being planted in warmer climates.

If grown in partial shade, temperature shifts are more likely than if grown in total shade or total sun. Lemon trees benefit from steady, warm temperatures.

Lemons Taste Better When Grown In Full Sun

Sunshine will literally make the fruit taste better! The reason is the way that fruits react to the wavelengths of light emitted by the sun.

According to the University of Florida, red and far-red light, both of which are emitted by the sun, manipulates the chemicals responsible for flavors in fruits, making them taste better.

While the research was aimed at commercial fruit production, the same concept can be applied to your yard! The more sun, the tastier the lemon.

Of course, they aren’t specifically discussing lemons, but if you’ve ever grown a lemon (or any fruit) indoors and wonder why it didn’t taste as good as the store – now you may have an answer!

Lemon Trees Produce Stronger Roots When Grown In Full Sun

We talked a lot about how the sun helps lemon trees photosynthesize so that they can produce sugar to feed themselves.

Not all growth on the tree happens above the ground. The roots below the surface are just as important to a lemon tree’s health as the branches, leaves, and fruit.

Roots help the lemon tree acquire water which is necessary for photosynthesis. They also absorb nutrients that help keep the lemon tree nourished. Lastly, roots help to stabilize the lemon tree so that it doesn’t blow over during a bad storm.

Full Sun Will Give Energy To The Roots 

Lemon trees grown in full sun will have enough energy to divert to root growth, which helps the overall health of the tree.

Without strong roots, the lemon tree may not be able to absorb water and nutrients as well and the tree will not be as stabilized. This can cause stunted growth, yellowing of leaves, and lower fruit production.

Full sun can even help lemon trees survive mild winters!

Full Sun Conditions Promote A Thriving Lemon Tree

We’ve gone over several reasons why planting lemon trees in full sun is a good idea. There will be more fruit, faster growth, and stronger roots – you get the gist.

Sunshine also helps the overall health of the tree. Lemon trees can be targeted by several different pest insects such as the brown citrus aphid, citrus leafminer, and rust mites.

Now planting your lemon tree in full sun isn’t going to STOP these pests from targeting your lemons. Rather, the full sunlight will help give your lemon tree a better chance of fighting them off due to the nourishment it provides the tree.

In addition to pest prevention, sunny conditions help lemon trees dry out faster after heavy rains. This helps prevent fungus and other unsightly growths from taking hold of your lemon tree.

How Much Sun Do Lemon Trees Need?

We keep saying the words ‘full sun’ to describe the amount of sunlight that lemon trees need. What exactly is full sun and how many hours of sun does your lemon tree need?

Full sun refers to giving plants at least 6 hours of direct sun per day. According to the University of Maryland, lemon trees will benefit from even more sun, performing best at 8-12 hours of sunlight.

Depending on if you are growing your lemon tree indoors or outdoors, it might be difficult to achieve 8-12 hours. Your lemon tree will do just fine with 6 hours. Just keep it close to a window!

However, if you’re looking to get the largest fruit production, the tastiest fruit, and the fastest growth, you’ll want to plant your lemon tree somewhere that gets at least 8 hours of sunlight per day.

You can view the full timeline of a lemon tree here to get a view of how long it’ll take your lemon tree to grow in full sun.

Can Lemon Trees Survive In Shade?

By now we know that lemon trees thrive when planted in full sun. You’ll get more fruit and a healthier tree.

Not everyone who plants a lemon tree is looking to harvest the fruit, though. You may just want to have a nice houseplant or shade tree. If that’s the case, is it okay to plant lemon trees in shade?

A lemon tree planted in shade will have a few different problems:

• May not bear fruit
• Weak roots
• Weak branches
• Flowers may not bloom or will be dull
• Slow growth
• Temperature Stress
• Fungus growth
• Increased pest problems

Why Lemon Trees Don’t Do Well In Shade

Overall, lemon trees do not do well when planted in shade. They may survive for a few years, but the health of the lemon tree will continue to decline.

The only time that it is okay to plant lemon trees in partial shade is if the area where you live experiences temperature extremes above 90℉ daily. In this case, the shade will help protect your lemon tree from sunscald and other issues related to too much direct sun.

What About Cloudy Days?

If lemon trees do not grow well in shade, what happens to them on cloudy days or during inclement weather?

Lemon trees will be okay on cloudy days. Despite not being able to see the sun, sunlight still reaches the earth on cloudy days (otherwise, it would be dark!)

According to an article in the Journal of Solar Energy, sunlight on cloudy days is called diffuse radiation and is spread evenly over the landscape as opposed to strong direct light on sunny days.

Basically, Lemons Will Absorb Less Sun On Cloudy Days!

In the study, they used solar panels that pointed directly at the sun on sunny days to capture the most energy. However, they found that solar panels pointed directly at the sun on cloudy days received about 50% less sun than those that were simply placed horizontally to capture the most surface area.

So, inferring that research with lemony-sighted glasses…

In other words, lemon trees will absorb less sun on cloudy days, but they still receive an even amount of sun no matter where they are planted.

If there are a substantial amount of cloudy days in a row, keep an eye on your lemon tree and make sure it is getting enough water and nutrients to help offset the lack of sunshine but just note it’s super natural for fruit trees in general to adapt to cloudy days.

How To Give Your Indoor Lemon Tree Enough Sun

So far, we’ve talked a lot about outdoor lemon trees, where to plant them, and how much sun they need.

Folks who can plant outdoor lemon trees live in just a few select places in the United States such as Florida, southern Texas, and California.

Not all hope is lost! The rest of us can still grow lemon trees but they will have to grow indoors during the coldest times of the year.

Tips To Growing Lemon Trees Indoors 

The two major varieties of lemon trees that can be planted indoors are Ponderosa lemon and Meyer lemon. These two can be pruned to remain small and are also available in dwarf varieties.

There are a few different things you can do to ensure your indoor lemon tree is getting enough sun, despite not being outside in the actual sunshine:

• Place it in the right location: Inside, you’ll want to place your lemon tree near a south-facing window. This will receive the most sunlight throughout the day.
  
• Place it outdoors in summer: When all threat of frost is gone, you can begin acclimating your lemon tree to the outdoors. By the time summer rolls around, keep your lemon tree outside at all times in a sunny spot that gets at least 6 hours of sunlight per day.
  
• Use grow lights: Grow lights are an excellent way to supplement your lemon tree with light when growing indoors. Feel Show’s Grow Lights for Indoor Plants is a great choice for lemon trees.

The grow light stand can raise up to 60 inches to accommodate a slightly larger lemon tree. The lights provide red, blue, and white spectrum lights which mimic what is given off by the natural sun.

The great thing about grow lights is that you can leave them on for 8-10 hours a day, giving your lemon tree some much-needed sunlight that it may not get indoors during the winter.

Wait… Can Lemon Trees Get Too Much Sun?

Lemon trees prefer to be planted in full sun, but is it possible for them to get too much sun?

Yes, lemon trees can get too much sun. However, this typically only happens in hot climates that see little rain.

If your lemon tree is getting too much sun, it may show some of the below symptoms:

• Stunted growth
• Rotting fruit
• Raised brown spots (caused by sunburn)

The first sign you will notice is probably rotting fruit, followed by sunburn. Lastly, you’ll notice your lemon tree isn’t growing very fast. If you’re having problems growing your lemon tree, we always suggest contacting a professional.

How To Protect Your Lemon Tree From Too Much Sun

If you live in a very hot, dry, sunny climate, you may need to take steps to prevent your lemon tree from getting too much sun.

Normally, lemon trees love to be planted in the sun and will thrive if given enough water and a few cloudy days here and there. However, some climates are super sunny and super hot, an unfavorable combination.

Plant Your Lemon Tree in Partial Shade 

The best way to protect your lemon tree from the sun is to plant it in partial shade when it is growing in extremely hot climates.

Commercial growers sometimes use sunscreens to protect their citrus trees, but this isn’t really feasible for the average homeowner. Instead, simply plant your lemon tree somewhere where it will receive a bit of shade during the day.

Partial shade will prevent sunburn and give your lemon tree a much-needed break from the harsh sunlight. 

Other Things You Can Do So Your Lemon Tree Thrives

In addition to using shade to benefit your lemon tree, there are a few other things you can do to make sure your lemon tree thrives in a hot and sunny environment:

• Adequate water: When conditions are hot and sunny, your lemon tree will be thirsty! If it’s been dry for 5 or more days, give your lemon tree a thorough watering to keep it healthy.

Note that watering should only be done while the tree is blooming and producing fruit. Otherwise, watering is not necessary unless there is a severe drought.

• Use fertilizer: Fertilizers can help struggling lemon trees bounce back by providing much-needed nutrients to the soil. Down To Earth Organic Citrus Fertilizer Mix is an excellent choice and should be applied 3 times per year.

It’s recommended to apply fertilizer in late winter, late spring, and early fall. This particular citrus fertilizer mix has an NPK ratio of 6-3-3, meaning 6% nitrogen, 3% phosphorous, and 3% potassium. This is an ideal ratio for lemon trees.

You can read more about our recommended best lemon tree fertilizers here.

That’s A Wrap!

Lemon trees are an amazing addition to the yard or home. There’s something special about being able to harvest your own fruit, but lemon trees will only fruit if the conditions are right.

One of the conditions lemon trees need to grow and thrive is adequate sunlight. Now for a quick recap.

The reasons why lemon trees grow best in full sun include:

• Faster growth
• Higher fruit production
• Better blooms
• Lower temperature fluctuations
• Better tasting fruit
• Stronger roots
• Overall tree nourishment

Lemon trees grown indoors can be placed outside in the summer to give the trees adequate sunlight. In the winter, the use of grow lights can keep your lemon tree happy and healthy.

When grown in extremely hot and sunny climates, it may be beneficial to plant your lemon tree in partial shade to protect it from sunburn. In other climates, lemon trees planted in shade may have stunted growth, low fruit production, and lackluster blooms.

If you’re thinking about planting a lemon tree, reach out to a local arborist who can help you pick the right spot and give you tips on how to best take care of it!

References

Boaretto, R. M., Hippler, F. W.R., Ferreira, G. A., Azebedo, R. A., Quaggio, J. A., & Mattos Jr, D. (2020). The possible role of extra magnesium and nitrogen supply to alleviate stress caused by high irradiation and temperature in lemon trees. Plant and Soil, 457, 57-70.

Garcia-Sanchez, F., Simon, I., Lidon, V., Manera, F. J., Simon-Grao, S., Perez-Perez, J. G., & Gimeno, V. (2015, October 14). Shade screen increases the vegetative growth but not the production in ‘Fino 49’ lemon trees grafted on Citrus macrophylla and Citrus aurantium L. Horticultural Science, 194, 175-180.

Quaggio, J. A., Mattos Jr., D., Cantarella, H., Almeida, E.L.E., & Cardoso, S.A.B. (2002, December 06). Lemon yield and fruit quality affected by NPK fertilization. Horticultural Science, 96(1-4), 151-162.

Tomas-Barberan, F. A., & Espin, J. C. (2001, June 13). Phenolic compounds and related enzymes as determinants of quality in fruits and vegetables. Journal of the Science of Food and Agriculture, 81(9), 853-876.