For years I’ve had an indoor herb garden in my apartments – useful in a pinch for cooking. Three years ago, I found out there are a variety of miniature fruit-growing citrus trees that can be grown indoors! Excited, I purchased a Moro blood orange tree (from Brighter Blooms, but there are other websites that sell them as well). Not only did my ~3 foot tree double in size over that time, but it successfully produced blood oranges three times. In moving, I unfortunately had to give away my precious tree, but I thought I’d share my personal care instructions with any would-be indoor blood orange tree (or any citrus tree for that matter) gardeners:
- Trees need a lot of sun. Generally >8 hours a day of direct sunlight is necessary for healthy growth. In the Northern hemisphere, the directions that provide the most sun from highest to lowest are South, West, East, and North. A blood orange tree will do well with South and West facing windows (assuming unobstructed view), survive with East facing windows, and die with only North facing windows.
- Daylight bulbs help! Daylight CFL and LED bulbs like you have in your regular lamps/fixtures provide useful light. They don’t replace sunlight, but they contribute a bit.
- Temperature is best between 55° and 85° F. Indoor temperatures averaging 65° are conducive to growth (assuming other conditions are conducive). Colder temperatures for an extended period of time (at least a couple of weeks) are a cue to the tree that it’s fruit-bearing time.
- Blood orange trees like humidity >50%. If humidity is lower, which is common in the winter when the heat is running, spray the leaves with a heavy mist of water once/twice a day. Trees absorb sunlight through their leaves, so make sure they remain dust free/happy. Humans do best when humidity is above 30%, so having a humidifier around for winter is a win/win.
- Avoid putting the tree right in front of a vent, if possible.
- Use citrus soil , which is specifically designed to “breathe” (lightweight, drains well). It also has the right mix of nutrients (every type of plant needs a different combination).
- Water once/week. Overwater, making sure there’s room and properly loose soil (see next bullet) for excess water to drain through (so that the tree does not become “waterlogged”). The hole in the planter, and stilts between the planter and base allow excess water to escape. Blood orange trees do best in very moist soil, but need air to “breathe”. I’ve never measured out the exact amount, but 1.25-1.50 gallons per week should be right for a 5-6′ tall blood orange tree.
- Blood orange trees require plenty of iron, manganese and zinc to produce healthy fruit, so use a liquid cactus or citrus plant food roughly once per season.
- Gently remove yellow/dying/dead leaves. These leaves take the plant’s resources away from healthy limbs/leaves that need it more. Yellow leaves may indicate a lack of fertilization, nutrient imbalance, or overwatering.
- Every 1-2 years, replant. The tree will become root bound, and will need to be removed, have its roots loosened/pruned, and then replanted with fresh/additional soil every 1-2 years.
- Produce fruit February-April, but indoor trees may produce fruit and at different times or not at all. Plants take cues from the amount of sun, temperature, and nutrients to know when to change growth phases. If the temperature gets colder, and/or there’s less light for the tree, it will think it’s time to produce fruit.
- What fruit production looks like: First white flowers bloom, with little green balls growing in the middle, which will eventually become the blood oranges. If the tree starts to bend under the weight of the fruit, cut a few off. Likely only 3-4 full sized blood oranges can be supported by the strength of the trunk.