While you could buy a fully grown lemon tree from your local garden centre, growing your own is a far more rewarding process. It’s also a lot easier than you might think. This guide will take you through everything that you need to know about how to grow a lemon tree from seed.
Interested in Growing a Lemon Tree?
You can be forgiven for thinking that lemon trees can only grow in hot climates. Actually, with the right care, lemon trees can thrive in most homes anywhere in the world.
Lemons are one of the most widely used citrus fruits in the world. They’re also packed full of nutrients such as Vitamin C and B-complex. These fruits are used in everything from indulgent cakes to drinks and cold remedies.
Not only will your own lemon tree provide you with a good source of lemons throughout the year, it’s also a fragrant and attractive plant. Its white flowers, glossy green leaves, and yellow-orange fruit will add interest to any window area.
How to Grow a Lemon Tree from Seed
Lemons are perennial plants when grown in USDA zones 9-11, but they can also be grown indoors. By growing the plants indoors you can guarantee that they will have the right level of warmth. These trees need to be in 55- 77°F, with plenty of light. You can also protect them from drafts and ensure that they have enough water.
A quick note before we look at how to grow a lemon tree from seed: while the seed may germinate quickly—usually within 3 weeks—it’ll take between three and five years before the tree is able to produce lemons. Also, bear in mind that lemons grown indoors can take a couple of months to ripen.
Choosing Your Lemon
You will, of course, need a lemon seed. They’re easily obtained: simply cut open the nearest lemon. If you don’t have a favorite lemon variety that you really want to grow, your choice doesn’t really matter. Lemon trees don’t tend to grow overly large, regardless of the variety. This means that they can all be grown in pots.
If you’re concerned about size, you may want to consider smaller or dwarf varieties. Eureka, or its variation the Pink Eureka, are both popular and long-established indoor varieties. Alternatively, the Meyer lemon is an increasingly popular variety. This compact, almost ornamental lemon is famed for its sweet flavor, and is often the top choice for chefs and TV cooks.
Ultimately, the only real requirement is that the lemon that you take seeds from should be juicy and flavorful. Selecting a good parent gives your plant a good chance of successfully replicating these qualities.
Select the Best Seeds
You’ll also improve your chances of success if you choose organic lemon seeds. Some non-organic lemon seeds are dormant, meaning that they’re incapable of germinating.
The seeds that you select should be plump and healthy looking. Discard any seeds that seem small, or are shrivelled up like a raisin. These seeds either won’t sprout, or will struggle to grow into healthy seedlings.
Some people like to plant as many as five lemon seeds at the same time. This is because not every seed that you plant will grow, so it’s good to have some backup options. If more than one seed does sprout, you can keep the young seedlings for a while and eventually select the healthiest. Alternatively you can allow all the seedlings to grow and give away your surplus trees as gifts to friends and family.
Remember as well that not all seeds will produce fruit that’s identical to their parent plant. The fruit from your saplings may prove to be inedible, or just not as nice as the parent’s. Some may not even produce any edible fruit at all. This is another good reason to plant more than one seed, just in case.
Even if your tree doesn’t fruit, it’s still an attractive tree to have in your home or garden.
Prepare the Seeds
Remove the seeds from the lemon pulp and select the best ones.
Wash your chosen seeds thoroughly under running water, making sure that all lemony traces have been removed. This is important because the flesh or gel-like substance that covers the seed contains sugars. If this is allowed to remain on the seed it can foster fungal disease, which will kill the seedlings.
You may notice that the seed is covered with a thin, brown film. Some people like to peel this off, believing that removing it encourages germination. This isn’t necessary. Germination will occur whether the brown film is removed or not.
Once clean, the seeds should be planted as quickly as possible. Allowing the seeds to dry out may prevent them from germinating.
Prepare the Plant Pot
Start your seeds off either in a small plant pot or in a seed tray. By doing this, you’ll be able to provide a controlled environment, thus giving your seedlings the best chance of thriving.
Whether you choose to use a seed tray or a plant pot, make sure that it’s clean. This reduces the chances of any unseen diseases or pests attacking your plants.
Your chosen pot or seed tray should also have drainage holes at the bottom of it, so moisture doesn’t get trapped in the soil. After all, wet soil can rot your seeds. If there are no holes, you’ll need to drill some into the bottom of the pot or tray.
Terracotta or Not?
Many people find that their lemon trees struggle when placed in terracotta pots. This is likely because the clay that the terracotta pot is made from can alter the pH levels and nutrient quantities in the soil. Plants also tend to dry out more quickly in terracotta pots.
While many people avoid terracotta for this reason, you can use a terracotta pot if you apply a non-toxic sealant to it and allow it to dry before planting up. This should help to avoid many of the associated problems.
You don’t need a large pot initially. Choose one that’s 3 to 4 inches wide and no more than 6 inches deep, as that’s more than big enough for one seed.
Some people like to sow more than one seed at once.If you intend on going this route, this you can sow up to 5 seeds in a larger pot. Just allow them all a bit of space so that they can spread their roots without becoming tangled.
When the seedlings grow large enough, they can be separated and placed in individual pots.
A good, general purpose potting compost is fine. Continue to use this multipurpose soil or compost as the seeds mature from seedlings right through to adult trees. Lemon trees will grow in most soil types as long as they are well draining. While most fruit trees love water, they don’t like to sit in it for long periods of time.
More competent or adventurous gardeners like to mix their own compost. If you want to try, aim for a blend of 50% peat moss and 50% perlite. You can then introduce a handful of vermiculite to the mix, which will prevent the soil from drying out quickly. Add some organic fertilizer to give your seeds an extra boost.
Some gardeners like to start their seedlings off in pasteurized soil, while this help to prevent disease attacking the seed or seedling it is not something that is necessary unless you have a particularly persistent pest problem. I have always used a good, fresh general purpose compost and have had no problems.
Remember that lemon trees prefer acidic soil, so be sure to test the pH levels regularly.
A Note Aboute Preparation:
You need to prepare the compost before adding it to the pot or seed tray. Place the compost into a bucket or container and add some water. Mix the compost and water together with either your hand or a trowel. Continue to do this until the compost is evenly damp.
Evenly damp compost is difficult to describe—it shouldn’t be soggy, but it also shouldn’t be overly dry. A good way to test its dampness is to insert a screwdriver or stick into the mix. This should be long enough that it can reach halfway into the container. If inserting the stick is a smooth process, the soil is probably evenly damp. In contrast, if it’s too dry, it’ll feel like the object is scraping through the soil.
When you’re happy with your compost mix, fill up your pot. Leave a gap of about 1 inch at the top.
Sowing the Lemon Seed(s)
Make a half-inch deep hole in the soil with either your finger or a pencil.
Place the seed in the hole, with the pointy tip facing down into the soil and the rounded end facing up to the light. Cover with soil.
Gently sprinkle with water, but don’t use a watering can. A spray misting bottle is ideal instead. Don’t soak the soil too much as this can rot the seeds.
The Germination Process
If desired, place your pots into a small propagation chamber to help speed up the germination process. These are easily available from your local garden centre. Alternatively, I like to place the pots in clear plastic bags. Use a rubber band to secure the end, and poke a few holes to allow air circulation.
Either method will prevent too much moisture from escaping and the soil from drying out. Don’t worry if you notice condensation forming: this will rain down onto the soil, keeping it moist. If you do see the soil drying out, remove the plant and water gently. Once watered, return the plant to your propagation chamber.
Place the seed tray or pots in a warm location, somewhere between 68- 82.4°F. Try to avoid placing the tray or pots anywhere that’s too sunny. While light is vital for growing healthy plants, seedlings are too delicate to handle direct light. In fact, too much sunlight can “cook” the young plants.
The same applies to warmth: too much heat can also bake seedlings to death. Place your hand gently on the soil to test the temperature. If it feels too warm, remove the plastic covering.
Mist or spray the seeds every 5 or 6 days, and never allow the soil to completely dry out. If conditions are perfect, seedlings will start to appear in two to three weeks.
Once you notice sprouts, remove the plants from the propagation chamber. Keep them in a warm, light location, away from direct sunlight. Continue to mist or spray the plants regularly.
An Alternative Germination Method:
If done correctly, this method is just as effective as the conventional germination method.
Dampen a paper tower and place it on a flat surface, smoothing out any creases. The paper towel should be able to fit inside a clear plastic resealable or zippered bag. If it’s too large, fold it in half.
Select between 5 and 10 lemon seeds. Even if you only want to grow a single lemon tree, it’s wise to start with several seeds. Remember, not all of them will sprout.
After cleaning the seeds, place them on the paper towel. Don’t bunch them seeds together: make sure there’s a gap of a few inches around each seed. This will allow their roots room to germinate.
Place the paper towel in the plastic bag and seal it tightly. Next, put the plastic bag in a dark, warm location that’s between 68 and 72°F.
Germination will take around 2 weeks to occur. Some seeds may take slightly longer, so don’t be disheartened if they don’t sprout immediately. Remove the seedlings when their tails are about 3.15 inches long. Follow the sowing instructions as mentioned earlier.
These seedlings can now be placed in a warm, sunny location. Make sure to water or spray them regularly, so they don’t dry out.
Caring for Lemon Trees
Now that you have some seedlings, you can watch them grow into healthy lemon trees.
There are occasions where a single seed will produce more than one seedling. If this happens to you, don’t worry—simply let the seedlings continue to grow. Once each seedling has produced four or five leaves, you’ll be able to separate them.
To separate the seedlings, carefully remove them from the soil and gently pull them apart. Each seedling can now be planted into its own pot. In cases like this, it’s common for one of the seedlings to develop into a plant that’s identical to its parent: the “true” plant. The other seedling(s) will probably grow into a special cross variety, meaning that you’ll have your own unique lemon.
Make sure your seedlings get around 10 to14 hours of light each day. Older lemon trees will be more than happy with just 8 hours. If you’re struggling to provide enough natural light for your plant, a grow light (or even a standard lamp), can provide ample amounts of artificial light instead.
Placing your lemon trees in an east- or west-facing window will allow them to bask in plenty of indirect light. If you want to keep your tree in a south-facing window, hang a net or sheer curtain over it to protect the seedlings from too much direct light.
It’s vital to ensure that you water your lemon trees on a regular basis.
These trees love water. Don’t worry if you find that you have to water them as frequently as two or three times a week: this is perfectly normal. Just be careful not to let the plants sit in water, as this can prevent oxygen absorption and may lead to root rot.
If you’re unsure when to water, just wait until the soil’s surface feels dry. Don’t let the soil dry out too much: it should be moist when you stick your finger into it. For a more scientific method, use a soil moisture gauge. These are easily acquired online or in garden centres.
If you’re growing your tree in a pot, the easiest way to know when the plant has had enough to drink is to water it over a sink. When water starts to drip through the drainage holes in the bottom, you’ll know that the soil is sufficiently moist and unable to take on more liquid.
Alternatively, if your pot is sitting on a tray or a saucer, you can water from the bottom up. Simply pour some water into the tray and allow the plant time to absorb it. Continue adding water in small doses like this until the absorption rate slows significantly or stop completely. This is a reliable sign that the soil has taken on enough moisture.
Finally, don’t use water straight from the tap. This can be too cold and can send plants—particularly delicate seedlings—into shock, causing leaf drop or wilting. I like to draw the water into a container and allow it to stand for a few hours before watering.
Allowing the water to stand for a while also means that any chemicals present in the water have the opportunity to dissipate. As such, there’s little danger of them harming your plant. If you’re very concerned about the chemicals in your water supply, use a water purifier to guarantee that your plants are safe.
Once the seedlings are slightly larger, you can start to give them an occasional small dose of fertilizer. Feeding your plants on a regular basis will encourage them to grow into strong, healthy trees.
Incorporate a water-soluble fertilizer high in potassium and magnesium into your watering routine. Apply the solution once a fortnight in the growing seasons (spring and summer). Reduce this to monthly during the autumn and winter when the plant’s growth naturally slows.
While many good organic fertilizers are available, one alternative is to apply Epsom Salts. These are a good source of both magnesium and sulfur. Stir 1 tablespoon of Epsom Salts into half a gallon of water. This solution can then be applied to plants once a month.
Composting for Indoor vs. Outdoor Trees
Alternatively, if you intend on keeping your lemon tree in your home or a greenhouse, you can apply a general indoor plant fertilizer that contains micronutrients on a monthly basis.
Twice a year, apply an organic fertilizer such as compost or vermicompost. Application of either will add nutrients to the soil. If your lemon tree is outside, the easiest way to add compost is to dig a trench around the tree. Then fill the trench with the aforementioned compost. Nutrients will then work their way through the soil to the tree’s roots.
If you’re growing the tree in a pot, there are two ways to add the fresh compost. Either remove the top level of soil from the plant pot and replace with fresh compost, or you wait until you’re repotting your plant. Once you’ve positioned the plant in the new pot, use some of the compost to finish planting it up.
Fertilizing your lemon trees on a regular basis is vital if you want them to produce lots of flowers and fruit. If you’re unsure how often to apply the fertilizer, or how much to give, remember: less is best. You can always add more if need be.
You’ll need to trim the tree’s branches as it grows. Do this during the winter, or at the start of spring when the lemon tree has fewer leaves. Sharp scissors or garden shears will allow you to make clean, precise incisions, thus reducing the chances of harming the plant.
Try not to prune the leaves during the spring and summer months. However careful you are, there’s always a chance that you may accidentally remove blossom or discourage the plant from growing and flowering.
While you should confine your pruning to the winter or early spring, don’t be afraid to remove any dead or brown leaves as soon as you notice them. Swift removal can help to prevent plant mould and other diseases from developing.
Regular pruning helps to encourage the plant to put its energy into flowering and producing fruit. Remember, a thin tall tree is one that’s in need of pruning.
Repotting Lemon Trees
Eventually the lemon tree plant will become too big for its pot. Plant growth that either slows or stops completely is a sign that the plant has become pot bound: too big for its container. You may also notice that the soil is drying out more quickly than usual. Another sure sign is when its roots start to poke out of the drainage holes.
Repotting is a relatively simple process that’s pretty much the same for every plant. The best time to repot your lemon tree is in the spring, just as it begins to wake from winter dormancy, and before the new year’s growth begins in earnest.
Select a clean pot that’s slightly larger than the current one—no more than 1 or 2 inches bigger. As the pot size increases, the depth of the pot should increase as well. Lemon trees have deep roots, so a deep pot is vital for a healthy root system. When your plant is fully grown, it should be in a pot that’s between 12 and 18 inches wide, and 10 to 16 inches deep.
Remember this increase in pot size should be gradual. A dramatic increase can traumatize a plant. This may, potentially, lead to leaf loss or even death.
Remember to make sure that the pot you select has drainage holes in the bottom to allow excess water out. If your chosen pot has no holes, it’s an easy enough task to drill a few in.
Once you have the clean pot ready, remove the lemon tree from the old pot. If the roots are tightly bound together in a “root ball”, gently tease them free. Also gently brush off as much of the old compost as possible. Try not to damage the root system as you do this.
Next, put some fresh potting mix or all-purpose compost into the new pot. You should aim to put enough in there so that the top of the root system sits just below the lip of the new pot when placed inside.
Position your tree in the centre of the pot and add more compost or potting mix. While you want to fill the pot, try not to pack in so much that it becomes compacted. Also remember that lemon trees dislike having their roots completely buried: the top of the root system should be left uncovered.
You should also try to leave some space between the compost and the top of the pot to allow for watering and growth. After you’ve planted your lemon tree, water in well and return it to its usual spot.
Pests, Diseases and Other Problems
Check your young plants regularly for any signs of disease. Prudency here can prevent a small infection becoming a major problem.
Don’t be fooled into thinking that just because your lemon tree is growing in your home it won’t attract pests.
Aphids or whiteflies can be easily removed by spraying a solution of warm water and dishwashing liquid or onto the leaves. Make sure to apply the solution to both sides. Apply a few times to ensure that the pests are fully gone. Another option is to apply neem oil to the leaves. An organic solution like this is not only effective but means that the fruit will still be edible.
If the lemon tree’s leaves begin to curl, or if you notice little passageways carved into the foliage, then it’s probably an indication that your tree is under attack from the citrus leafminer.
As the name suggests, this little pest regularly attacks citrus plants by burrowing through a leaf’s outer layers to feed on the soft tissue beneath. Organic insecticides or neem oil can save your plant from this persistent little pest.
Note that even when the lemon trees are young, it’s safe to use small doses of these pesticides.
Wilting or growth dieback can be a sign of over watering. Another indication of this is a wispy film of mold on the surface around the plant’s base. If this is the case, allow the soil to dry out before watering again. Alter your routine so that you give the tree less water, on a more regular basis. If the mold persists or worsens, repot the plant in a slightly larger container.
Harvesting your Lemons
After the fruit appears it may take a month to fully ripen. This is especially true of lemon trees grown indoors.
Don’t worry that you have to use ripe fruit immediately. It holds on the lemon tree in good condition for many months after ripening, providing long-term self-storage.
To remove your ripe lemon, carefully twist it so that it separates from the plant.
Don’t be disheartened if your lemon tree doesn’t produce fruit straight away. Some trees won’t produce fruit for 5 years. Others take as long as 15 years before they’re ready to start fruiting. Just know that it’s always worth the wait.
A healthy lemon tree is an attractive and fragrant addition to any space. Enjoy growing your own!