The Best Indoor Lemon Tree Care Guide

Lemons are one of the most popular of the citrus families. They can be used in desserts, beverages, dinners, and appetizers. Growing them indoors can be tricky, but if you know what they need and can supply it, you will do fine. So, if you want to learn more about lemon tree care, I’m at your disposal!

Natural Light

Lemon trees need, what is called, full sun. Full sun is 8 or more hours a day. Just because the sun is shining on it when you leave in the morning, it does not mean that it is in full sun. The bare minimum would be 6 hours. Though, with that few hours, your fruit production will be much lower than is possible, if at all, for that plant. Your tree will also not be able to make as much food for itself at that light level. Some people will use the lemon tree as indoor plant, so it yields lesser fruit than the ones outside.

Is it possible to bear fruit though? Yes. It will be just sparse or sporadic. Indoors, you will need to supplement the lighting. Therefore, you’re going to need artificial lighting.

Artificial Light for Lemon Trees

For many years, indoor plant growers have used different types of artificial lights like Incandescent and Compact Fluorescent bulbs. These have all been an attempt to mimic the rays of the sun indoors, as they are hung or placed over the plants or pots to expose all the sides and leaves of the plant to the artificial light, all of these have a varying degree of effectiveness.

Grow light system for indoor lemon trees in action:

There are all kinds of materials that can be used as a container for your lemon tree.

Everything from ornamental, fancy-type containers made of ceramic to the common nursery type black pot and numerous things in between. I have seen people using plastic pickle buckets, Rubbermaid containers, and even garbage cans. You need to consider these conditions especially when you are still in the process of growing them from seeds.

The basic concept should always be the same:

• holes for drainage;
• ability to stand up to the moisture of the soil;
• and a large enough capacity to hold the needed amount of soil.

It will truly depend on what you want it to look like and how it will fit into your decor. As for the size that is needed, I try to go for the biggest that I can get, or at least twice the size of whatever pot it is in currently.

This is one of those topics that, if you ask five different people, what type of soil they prefer, you might get six answers!

There are those that like coconut husks and sand. Some like the peat and pine bark mix. Others use sand, perlite, peat, and pine. No, this is not a cop-out. Use what works for you, as long as it covers these three things:

• Well-draining– you do not want the water to sit in the pot for a long time. Sand offers the best drainage performance but it is not suitable for growing plants. It dries out too quickly and it lacks important nutrients.

• Able to retain some moisture – lemon trees do require a vast amount of water, they just do not want to sit in it all the time. (See #1 above) Straight peat moss would hold water forever and would not be suitable because of that.

• Sturdy enough to support the tree – for instance, perlite by itself would not work due to the lack of stability.

The same process and basis are used to grow a rubber plant and snake plant because these species are not that hard or strict to propagate.

If you do not want to play around with mixing your own potting mix, there are already-made concoctions out there. There are even companies that sell a Citrus/Cactus mix that works very well, such as Miracle-Gro.

Watering your tree is a little more complicated. Citrus love moisture, yet do not like to sit in water all the time. How much water is enough, or too much?!

What is the answer to this dilemma? Well, I am glad you asked.

There are two methods I use, sometimes in combination of each other.

• The first method – I give the plant a finger. I use my index finger and stick it in the soil, and if it is dry to the second knuckle, I water the plant. If it still feels damp, I wait a couple of days and then test it again.

• The second method – I use this one on a more regular basis. It involves a little more work. However, I like this method because it will also let you know if the soil has pulled away from the sides of the container or has become ”hydrophobic”. This happens when there is a lot of peat moss in your mix and it is allowed to dry out entirely. It is very hard to get the water to soak into it again.

To check, first, water the plant until you are absolutely sure the rootball is at maximum capacity. You might have to let it soak in a bucket or barrel for an hour or two. Then, either lift the pot or tip it to one side. Whichever way you do this, try and get the feel of the weight of the pot with the saturated rootball. After a couple of days, when you think the tree needs some water, lift it or tilt it again. Does it still feel pretty heavy? Then you should wait a few more days.

After that few days’ time has expired, do the lift/tip again. Do this until it feels approximately half as heavy as it did the first time you tested it with the saturated rootball. I use this method and it works for me.  This method works well if you have numerous size pots next to each other. As you can imagine, a very small pot will need water long before a large pot.

This is also where the well-draining potting soil works out well. If you do tend to overwater plants, as long as the drainage is working, it is actually very hard to give your citrus tree too much water. The optimum soil consistency is that of a wrung-out dish sponge.

Fertilizing and feeding your citrus trees can be a very diverse subject. Therefore, if you ask 5 people what they like to use, you will get 6 answers! Lemon trees are heavy nitrogen feeders. Nitrogen is the first number of the three on a fertilizer bag, such as 5-2-6. The five being nitrogen, in this example.

The best fertilizer that I have found is called Citrus-Tone. After using it, I saw very good results almost immediately. That is not to say that it is the end all or be all in fertilizers. I have had discussions with people that hate the stuff and use things that I do not like.

When it comes to indoor lemon trees, I prefer to feed them every 6-8 weeks all year long. As to how much, it will depend on the size of the container. Sprinkle it around the entire top of the soil, lightly, then water it in well. On average, ½ tablespoon per gallon of pot size should be enough.

It is okay to use a slow-release fertilizer also, I think of it more as a drip IV type of feeding. Lemon trees like nitrogen and slow release do not feed them fast enough for my taste. However, I do use it as a backup in case I can’t feed them regularly.

When your lemon starts to flower, this is the time that you will have to really get involved with your tree. Ideally, if the tree was outside the bees would pollinate the flowers to produce fruit. You will have to imitate this process by using a small paintbrush, similar to what they use in grade school and dab pollen from one flower to the other. Just swirl the brush in one flower then move on to another. Lemon trees do not require cross-pollination. Therefore, you only need one lemon tree to pollinate and produce fruit.

If you can get a lemon tree on a dwarfing rootstock, great! Chances are, you will never be sure if you got one or not, especially if you are growing your lemon tree from seed. The containing of your lemon tree will dwarf the plant somewhat, but it can and will eventually get to the ceiling. Check out our handy guide on tools used for gardening to pick your favorite cutting equipment.

Once the tree gets to the size you want it to be, just give it a haircut to maintain that size. Usually, just before the spring growth comes out is the time to do it, but, if your plant is indoors, it won’t have a seasonal cycle. So, prune it when it has gotten to the point of it being an issue, or right after you have harvested fruit.

Occasionally, you will have a pest or two, usually mealy bugs, aphids, or spider mites. Insecticidal soap or Neem Oil will be your best friends. Both are safe, organic, and will not harm you, your tree, or your pets. Follow the directions on the label and do periodic inspections of your plants to stop a full-blown invasion.

A few varieties to search out would be:

• Eureka or Lisbon Lemon – this is what you find in the grocery store.

• Variegated Eureka Lemon – this is the original pink lemonade, the flesh inside of ripe fruit is pink.
• Meyer Lemon – Not a true lemon, this is a cross between a sweet orange and a lemon, hence it being a “sweeter” lemon.
• Ponderosa Lemon – this football-sized fruit will be the envy of all your friends and neighbors.

In Conclusion

Your lemon tree will really want to be outdoors, and during the non-freezing temperatures, it will be very happy if it is. If you just do not have the room outside and must grow it indoors, follow these simple rules and it will produce just fine. Lots of supplemental light, moisture, and care, and you will have the most wonderful lemons you have ever experienced. Click to learn about the stages of growth for lemon trees.