Most gardeners will have a lemon tree in their garden. Citrus trees can even be grown in large pots, so there’s really no reason why you can’t grow at least one lemon tree at home. But, how do you select the best fertilizer for lemon trees?
In fact, if you treat your tree well and give it the right type of nutrients, one healthy and thriving lemon tree can provide you with more lemons than you need. The most important thing you have to know is that lemon trees require a regular dose of potassium to produce an abundance of citrus fruits.
After we look at some of the best lemon tree fertilizer choices that you have, I’m going to share with you my own experience of inheriting a non-producing lemon tree and how I turned this around.
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What Types Of Nutrients Do Lemon Trees Need?
Lemon trees need a good balance of the three main nutrients – nitrogen, phosphorus and potassium.
- Nitrogen is responsible for healthy green growth
- Phosphorus is mainly responsible for a nice healthy root system
- Potassium is a necessary ingredient if you want high fruit production
Apart from these major nutrients which are commonly referred to as the NPK ratio, lemon trees also require trace amounts of copper, iron, zinc, boron and manganese. You’ll find that these are normally found in high-quality balanced fertilizers available for citrus trees.
Types Of Fertilizers
When it comes to the best lemon tree fertilizers, you have many different choices. You can select from several different commercial fertilizers or you might prefer to use natural fertilizers.
Sometimes, a combination of both is the best solution to grow healthy citrus plants that produce plenty of fruit. Let’s take a look at some of the different options available.
Liquid fertilizers are also commonly referred to as water-soluble fertilizers because you mix them with water before applying them to your lemon tree.
These are excellent for lemon trees grown in pots or for when you want to give your tree an extra boost. The disadvantage to using this type of fertilizer on a regular basis is that you’re going to have to reapply it every couple of weeks.
This is because the essential nutrients in the fertilizer are available to the plant roots immediately but will get washed away the next time you water.
Here are some liquid citrus tree fertilizers that you might like:
This is a concentrated liquid fertilizer that is specially formulated for fruiting trees like lemons. It has a major nutrient breakdown of:
- Nitrogen 20%
- Phosphorus 3%
- Potassium 19%
What I particularly like about this formulation is that the potassium is almost equal in volume to the nitrogen. This will provide a good balance of healthy green new growth and an abundance of fruit. Applying this fertilizer regularly is great of you want your tree to grow fast and produce new leaves and branches.
It’s recommended that you apply this every 7 to 10 days during the optimum growing season.
This liquid fertilizer has an excellent nutrient makeup of:
- Nitrogen 20%
- Phosphorus 10%
- Potassium 20%
It also contains trace amounts of magnesium, sulphur, boron, copper, iron, manganese, molybdenum and zinc.
When feeding your lemon tree, all that’s required is mixing one tablespoon of the feed with 1 gallon (3.8 litres) of water and applying it to your tree. This fertilizer can be used on both the trees in your garden as well as any potted trees that you may have.
Granular fertilizer is best used on trees that are growing in the ground as you just scatter the fertilizer granules on the soil around the tree and then water them in.
Many granular fertilizers are either synthetic fertilizers or chemical fertilizers. But, you can also get these with more organic ingredients and these are generally labelled as slow-release fertilizer pellets.
Here are some granular citrus fertilizers you might like to try.
This granular fertilizer is a continuous-release fertilizer. Each application will feed your trees for around 3 months.
The nutrient breakdown of this product is:
- Nitrogen 8%
- Phosphorus 2%
- Potassium 10%
All you have to do is shake the granules around the dripline of your tree. Make sure that you follow the recommended application rates on the pack.
This product is just as easy to use on potted citrus trees as those growing in your garden.
This is a granular fertilizer which is also organic, so it’s definitely one I would consider using.
The nutrient breakdown is:
- Nitrogen 5%
- Phosphorus 2%
- Potassium 6%
The product also contains trace amounts of calcium, magnesium, and sulphur. It’s made from natural materials such as feather meal, poultry manure, bone meal, Alfalfa meal, greensand (natural sandstone), and sulfate of potash.
Citrus Fertilizer Spikes
Citrus fertilizer spikes are quite a clever solution for busy gardeners. Each spike is specially formulated to contain the right amount of nutrients to keep your lemon tree healthy. This makes them a great option if you often forget to apply fertilizer to your citrus trees.
All you have to do is push the spike into the ground near the base of your tree and the nutrients will be released over time. These fertilizer spikes are also ideal for lemon trees grown in pots.
Here are some of the better citrus fertilizer spikes available on the market.
These spikes are specially formulated for citrus trees but they are also ideal for other types of fruit trees. Here’s their nutrient breakdown:
- Nitrogen 9%
- Phosphorus 12%
- Potassium 12%
That is pretty much an ideal breakdown for fruiting trees such as citrus.
The spikes are also very easy to apply. All you have to do is measure a distance of 30 inches (76 cm) from the trunk and then use a hammer and the included plastic cap to hammer the spike into the soil.
In other words, according to the directions on the pack, you want to place the spikes just outside the dripline of the tree’s canopy. For this reason, I wouldn’t recommend using these particular spikes to fertilize potted trees as you might end up burning the roots.
You’ll probably need to replace these spikes once every couple of months. So, if you use two spikes at one time, you’ll probably use around 10 to 12 spikes per year.
But, don’t despair if you have a potted lemon tree and you really like the idea of these fertilizer spikes. There’s also a range available for container-grown trees.
After looking at the formulation of these spikes, I prefer them over Jobe’s regular spikes. Mainly because they’re organic and made from feather meal, bone meal and sulfate of potash.
Their nutrient breakdown is:
- Nitrogen 3%
- Phosphorus 5%
- Potassium 5%
To use these, you just insert the required number of spikes, as per the pack instructions, around the edge of the pot.
Another thing I appreciate about this product is that the spikes are pushed down below the surface of the soil so that they’re not within reach of the inquisitive nose of your dog. Plus, they’re totally organic making them safe to use around children and pets.
A natural fertilizer can either be something that you make yourself or it could be an organic fertilizer that you purchase from your local garden centre or nursery. Most organic fertilizers contain some type of animal manure as well as the addition of macro-nutrients.
Some organic fertilizers are also made from fish meal with added seaweed extract. While seaweed extract is not a fertilizer on its own, it is very helpful in maintaining the health of your citrus trees.
Those of you who read my articles regularly would be aware that I favour organic options and the use of natural products wherever possible in the garden.
Here are some organic fertilizers that I would recommend using.
I really like this fertilizer as it’s made from feather meal, fish bone meal, Alfalfa meal, and kelp meal. Other ingredients include langbeinite (a natural mineral containing magnesium and sulfate), basalt, potassium sulfate and zinc sulfate.
The major nutrient breakdown of this product is:
- Nitrogen 6%
- Phosphorus 3%
- Potassium 3%
The product also contains trace amounts of calcium, sulfur, iron and zinc.
To apply this fertilizer, all you have to do is measure the correct amount, according to the instructions on the pack, and sprinkle on the soil around the drip line. Always moisten the soil before applying fertilizer and again after.
This product can also be used on potted citrus trees by following the directions on the pack.
This organic fertilizer is a little different to the rest in that it comes in convenient little capsules. It’s only designed for potted lemon trees and dwarf varieties of other types of fruit trees.
This company has sustainability front of mind as even the canister that the capsules come in is recyclable. While you get 100 capsules in every pack, it’s recommended that you replenish these every 2 to 3 weeks.
Therefore, I would only recommend using these on potted lemon trees. However, application is simple and mess-free and there are no odours to contend with.
When Should You Apply Fertilizer To Your Lemon Tree?
Essentially, you want to fertilize your Meyer lemon tree (or any other variety) during its main growing season from spring right through to autumn (fall). The only time that you don’t need to feed your citrus is in the middle of winter. This is because your tree will be dormant during the main winter months and there will be very minimal nutrient uptake.
However, you do want to give your lemon tree a recommended amount of fertilizer in late winter or at least early spring, just before the blossoms start to appear.
Lemon trees are heavy feeders and how often you need to apply your chosen fertilizer will depend on which type you’re using.
How much fertilizer you need to apply will again, depend on the type that you’re using. Always refer to the instructions on the pack for the recommended dosages.
Granular or slow-release fertilizers can last from 3 to 6 months. So, I would suggest reapplying these every 4 to 5 months. Just make sure that the soil is moist and also water well afterwards.
On the other hand, liquid fertilizers need to be applied much more often. Ideally, you want to apply these every two weeks during the growing season from spring through to the end of autumn (fall).
Fertilizer spikes release their nutrients gradually and need to be replaced every couple of months. Once again, from late winter right through to the end of autumn (fall).
If you follow this general guide, your lemon trees should be healthy and thriving and provide you with plenty of fruit.
My Secret Formula That Turned A Non-Producing Tree Into A Bumper Crop
As I mentioned in the beginning, I want to share with you how I turned an old lemon tree with no fruit into a tree with an absolute abundance of lemons.
Unfortunately, I didn’t take a photo of the tree before I set about the task of rejuvenating it and getting it to actually fruit. However, here’s a photo of my tree right now.
As you can see, the tree is growing in a less-than-ideal spot (I didn’t plant it), but look at all those lemons.
So, when I first moved into this house, I started by giving the tree a decent prune. The growth was really crowded, so I opened up the centre of the tree and also reduced the height a little.
Then, I gave the tree a good feed with some organic slow-release fertilizer called Dynamic Lifter which is only available here in Australia.
Here’s My Secret Ingredient
Next, I decided to try my secret trick which I’m happy to share with you. I have an enclosed wood-burning heater in my house which I use over winter. Thanks to my horticultural training, I knew that wood ash was high in potassium.
As you might remember, I mentioned earlier that lemon trees need plenty of potassium to fruit well. So, every time I had some ash to empty, I would just scatter it around the base of the tree.
Nothing happened in the first year although the tree looked relatively healthy. But, the second year I got two lemons. Move forward to last and this year, and I have more lemons than I know what to do with.
My takeaway from this is that lemon trees really do like wood ash but it takes a couple of years to make an impact on the fruiting. So, if you have a non-fruiting citrus tree, give this a try and I’m sure you’ll be pleasantly surprised.
Frequently Asked Questions
This will depend on the type of fertilizer you’re using but generally, you want to feed your lemon tree from late winter right through until the end of autumn.
The only time you want to add Epsom salts is if your lemon tree has a magnesium deficiency. This can be seen by the leaves turning yellow even though the tree has been given plenty of nitrogen. If you use a good citrus fertilizer, you shouldn’t need to supplement with Epsom salts.
Yes, banana skins are high in potassium which will encourage your tree to produce lots of fruit. Try burying a few banana skins in the soil around the base of your tree. It might take a while before you see the results though.
Lemon trees are heavy feeders and need plenty of the right fertilizer throughout their growing season from late winter through to the end of autumn (fall). Remember that the best citrus tree fertilizers are high in potassium.
I’ve given you plenty of choices of suitable fertilizers that you can select. Which one will work best for you will depend on your preference as all the ones I’ve mentioned will make your lemon tree nice and healthy. You can also use these recommendations for other types of citrus such as lime trees.
If you happen to have a non-fruiting tree, why not try my simple trick of applying wood ash to the soil around the base of the tree for the best results? It might take a couple of years but I’m sure you’ll be delighted with the result.