There are a few things you should know about caring for a citrus tree.
We have more detailed information available (and a one-hour seminar if you're really into citrus), but here are the main things you should be aware of when it comes to caring for your tree.
How to water:
Citrus trees do not like wet feet, so let the soil mix dry out well between waterings. For each watering, fully water your tree and let the excess water run freely down and out. (Drainage holes are important!) If you use a saucer, make sure to discard any excess water.
How to know if the tree needs watered:
Pick the tree up and feel the weight. When the soil looks dry on top, pick it up and feel the weight difference. This is a great way to judge when your tree needs more water.
You may also leave a chopstick in the soil and check it periodically to see how far down the soil is moist. When the top inch is dry, it is ready to be watered.
Soil also plays a big part in how frequently you will need to water. If you use a different soil than what we have recommended (such as potting mix), you will likely need to water much less.
Without sunlight, citrus trees won’t grow! In the summer time, the trees can be placed outside to soak up the light they need. They are a little more demanding than most plants when it comes to light (they are tropical plants), so it will be important to ensure they have high-intensity light. Note: it doesn't matter where the light comes from (sunlight or grow light) - as long as your tree is getting the light it needs, it'll be happy!
Here are some tips for getting light:
- Place the tree in a south window (watch temperatures in the winter).
- Purchase a 1000W white light LED panel (we sell what we use!)
- If your tree is not getting the number of hours of sunlight it needs in a day, a grow light should be used to supplement some hours of light after the sun sets.
If you use a grow light, hang it about 12-18 inches above the tree and leave it on for 16 hours per day if that is the only source of light.
What kind of grow light should I use?
If you need a grow light, you'll want to make sure it has a PPFD (photosynthetic photon flux density) value of at least 500. The sun is at about 1200-2000 PPFD, depending on cloud coverage, and you want to try to replicate the sun to the best of your ability!
If the grow light doesn't boast about its PPFD value, it probably isn't a good one. If you're looking for a specific recommendation, check out the grow light we use.
General light requirements:
Note: as long as your tree has enough water (remember, they don't need much!), there is no such thing as too much light for citrus trees! The numbers below are minimums, not maximums.
Lemon: 4-6 hours (Meyer lemon trees are an exception and need 6-8 hours)
Lime: 4-6 hours
Kumquat: 3-4 hours
Orange: 4-6 hours
Grapefruit: 8-10 hours
If you would like to see flowers blooming on your tree, fertilizer is important! Look for fertilizers with an NPK ratio (macro) of 2:1:1.
It’s also just as important to ensure your fertilizer contains micronutrients! This list contains the micronutrient minerals that are vital for your citrus tree’s growth and production:
It’s very important to follow container instructions and to not over-fertilize as micronutrients are used by the plant in much smaller quantities and can burn plants if there are high concentrations.
Liquid feeds can be more efficient and give better results, though they are more expensive. Slow-release products are also recommended. Liquid feed and slow-release products can be used together with half the amount of slow-release fertilizer and half-strength liquid feed. Ensure that you follow all labels!
Since fertilizer is so important to ensure maximum fruit production, we also sell the fertilizer that we use. It is slow-release and fully degradable, so you don't have any beads left in the dirt! (Purchase our 4-year supply here!)
Note: If you are fertilizing and still seeing signs of nutrient deficiency, you likely have a pH problem. The pH of your water should be around 6.5. If it is too basic (above 7), the tree will not be able to take up the nutrients from the fertilizer. Click here for more information on pH.
Most citrus trees cannot withstand temperatures below freezing (32°F). The ideal temperature is about 75°F with direct sun. The tree may remain outdoors in the warm seasons until the nightly temperatures fall below 40°F consistently, at which point it will need to be brought indoors. If temperatures are above 90°F, you may need to move the tree out of the sun and water more frequently.
If indoor temperatures are cooler or you have a drafty window, a germination mat may help to keep the tree warm (get the heating mat we use here). You will know the tree is too cold if the leaves start to yellow and fall (though this can also be a sign of improper use of fertilizer or over-watering).
If your home is dry or the tree is placed next to a heater, mist the tree daily or place a humidity tray nearby.
A lot of people think that potting mix is universally great for any and all plants, but that is not true for citrus trees. Potting mix is very dense and is very good at holding onto water, which is TERRIBLE for citrus. Almost every instance we have seen of root rot has occurred because the tree was in dense soil.
For this reason, we recommend a soilless mix or a very airy soil. Now, we have a lot of experience with citrus trees and over several years of trying different brands of soil, we decided that none of them worked well enough for us. As a result, we now make our own soilless mix (check it out here!).
We use a 2:1:1 ratio of coconut chips, coconut coir, and perlite. This helps the tree to retain only the water it needs and let the rest drain out. Soilless mix also lasts up to about 10 years, so it very rarely has to be replaced, unlike potting mix.
We do realize that not everyone wants to purchase materials like this in bulk for a tree in a two-gallon container, so if that is a concern of yours, you can also just purchase some perlite to amend your soil. If you choose to do this, you should have about a 2:1 ratio of soil to perlite.
What type of pot should I plant my tree in?
The main two choices on the market are plastic and terracotta. We typically recommend plastic pots for citrus trees for a few reasons. Plastic will help keep the tree warmer, especially during the winter.
Terracotta also tends to hold onto water a little more, especially in colder temperatures. If you like the aesthetic of a terracotta pot better and really want to use one, we recommend putting the tree in a plastic pot and then putting the plastic pot inside the terracotta.
It is extremely important to make sure that whatever container you choose has drainage holes. And again, if you use a tray, make sure you empty it a few minutes after watering so that the tree isn’t sitting in water.
When can I plant up my tree?
A common mistake that we see a lot with citrus trees is planting them up too quickly. Citrus trees are very different from most plants in that they actually like to be root-bound. When citrus trees are rootbound, that signals to them that they have no more room to grow and that they should start focusing on fruit production.
Your focus with planting up your tree should be to slowly and incrementally move up in container size until you get to the desired tree size. We don’t recommend moving up more than one or two gallons at a time. If the tree gets put into too large of a container, there will be way too much soil for the amount of roots the tree has. This will cause the soil to retain water because the tree doesn’t have enough roots to soak it up.
Once you start to see roots poking out of the bottom of the pot, that’s a sign that your tree could use a new home or it will start focusing on production. When your tree is at the size you want it to stay, don’t move it up into any larger of a container. It will become rootbound and focus on producing that fruit you worked so hard for.
The details (in video form)
Want more detailed info about growing a citrus tree indoors? Oh, we got you. We're so obsessed with citrus trees that we literally gave an hour-long presentation. Buckle up!
Check out the video below!