Top 10 Questions About Lemon Trees

Lemons on a tree
(Image credit: Francesco Carta fotografo / Getty Images)

Need to know how to grow a lemon tree? What about how to treat common issues that pop up along the way? Then you've come to the right place. Gardening Know How strives to help avoid these issues, or at the very least amend them, by providing the best information possible"¦whether it pertains to growing lemon trees or other plants in the garden. And to that end, here are the top 10 questions about lemons and answers for successful cultivation of these commonly planted fruit trees. 1) How to fertilize a lemon tree? Fertilize young lemon trees once every 1-2 months during their active growing phase and once every 1-3 months during the fall and winter when the tree is dormant. Older trees do not need to be fertilized when they are dormant, but fertilizing lemon trees should be increased during active growth to once every 2-3 months. Select a fertilizer that is high in nitrogen or a balanced NPK fertilizer, optimally one that is specifically made for citrus. If the tree is having issues with flowering, try giving it some phosphorus rich fertilizer, like bone meal. When lacking phosphorus, it will not be able to produce blossoms (which means no fruit.). Fertilize either by foliar spray or spread it out in a ring around the base of the tree. Be sure not to place the fertilizer too close the trunk of the tree. 2) How to prune a lemon tree? Unlike other fruiting trees, lemon trees don't need to be pruned on a regular basis. They should have sprouts removed as well as dead or weak limbs or crossing branches. Bigger trees may also benefit from pruning to allow for better light penetration. Prune lemon trees after the fall harvest using sharp shears or a saw, and wear heavy gloves to protect from the thorns. Always make your cuts with the blade towards the tree to avoid damaging the bark. For large branches, use a three-cut system. Start with an angled cut 10-12 inches from the branch union then cut 1/3 through the branch from the other side. Finish by severing the branch a few inches up the length. 3) How to water lemon trees? Watering citrus trees, like lemon, can be somewhat tricky, as too little or too much water have the same results - possible death. Water container grown lemon trees much as you would a houseplant. Water deeply at intervals and allow the soil to dry between watering. Be wary of giving too much water since citrus don't do well with wet roots. Be sure the container has adequate drainage holes and place the plant atop a pebble filled saucer. Also important is relative humidity. Run a humidifier during the winter months when the air is cold and dry. Water lemon trees in the ground either manually or via rainfall once a week. 4) Why is lemon tree dropping leaves? It's an interesting thing about lemon trees; they hold onto their leaves when the tree is dry and then lose them when they get watered again. It's important to be consistent with watering citrus in general. Because these trees do not like "wet feet" (roots), overwatering may also cause the tree to lose leaves. Additionally, a lack of fertilization may result in a lemon tree dropping leaves. All three of these cause stress to the tree, and dropping leaves is its reaction to that stress. 5)  Why are leaves turning yellow on lemon tree? Yellow leaves on lemon trees may be a lack of water. When lemons are water stressed, they hold onto their leaves (until watered again), but the leaves may turn yellow as a last plea for irrigation. Water in-ground lemon trees once a week depending upon rainfall and those in containers as you would a houseplant, when the soil has dried or is lightly damp. Also, add a few inches of mulch to help the soil retain moisture. Other reasons for yellowing leaves may include insect pests or disease. 6) Why does my lemon tree have thorns? Aromatic, beautiful and with such mouth-watering fruit, it comes as something of a shock to see a lemon tree armed with thorns. Nature has provided the tree with theses spikes for the same reason that animals like porcupines sport quills - protection from predators. Thorns on citrus plants are most often found on tender, young trees and less so on mature trees. Because thorns can be, well a thorn in the side of a harvester, thornless hybrids have been developed and are readily available to gardeners. 7) What causes fruit drop on lemon trees? Well, one reason a lemon might drop fruit is if it has set more fruit than it can support. This is normal and doesn't affect the end production. In facts, this is simply nature's way of thinning itself. If fruit drop on lemon trees is excessive, however, it's probably due to an environmental factor such as too much or too little water, improper fertilization, excessive pruning, disease or insect predation. 8) Why doesn't my lemon tree bloom? If a lime or lemon tree has never bloomed, it might be poor rootstock; otherwise, the culprit is likely either a watering or fertilizing issue. Lemons need consistent irrigation, too much or too little messes with them. They also need a fertilizer for citrus trees that is high in potash and low in nitrogen. Excess nitrogen will give you gorgeous foliage but won't spur the tree to produce blooms, hence fruit. The addition of phosphorous will also encourage blooming. Also, lemon trees don't need much pruning, just the removal of spurs and dead or problem branches. Fruit sets on the ends of the branches, so any pruning should be judicious. It's possible that an overly exuberant pruning is the culprit. 9) How to care for potted lemon trees? Growing citrus in a container is great for those of us who don't live in warmer climates. A dwarf variety of lemon is a good candidate for container growing. Be sure that the container has adequate drainage and, because you want to be able to move it around easily, is on wheels. Lemon trees need consistent watering so put it on a schedule and be consistent. Container grown lemons also need to be fertilized regularly. A low nitrogen, slow release fertilizer is a great way to feed the tree, allowing it to absorb needed nutrients over a period of time. Humidity is important to your lemon tree so mist it daily or place it over a pebble tray. Prune out any sucker branches or dead or diseased limbs. Move the tree inside as temperatures begin to drop. 10) How to care for lemon trees in winter? Lemon trees do best when temps are in the 70's during the day and down to about 55 F. () at night. When temperatures fall below this, the tree goes dormant and can be killed when temperatures plummet. So, if you live in a cooler region, it's best to grow a lemon in a container. Be sure the container has wheels so the tree can be easily moved indoors in the winter. Provide the pot with a pebble tray or run a humidifier in the winter to add some humidity into the air. Cut back on fertilization during winter months. Supplement light with fluorescent grow lights. When temperatures warm up, wheel the lemon back outside so it can be pollinated by bees and other insects. Alternatively, you may be able to find a cold hardy citrus variety, depending on your location. We all have questions now and then, whether long-time gardeners or those just starting out. So if you have a gardening question, get a gardening answer. We're always here to help.

Amy Grant
Writer

Amy Grant has been gardening for 30 years and writing for 15. A professional chef and caterer, Amy's area of expertise is culinary gardening.