Growing Citrus as Houseplants

Citrus trees can be grown easily indoors! Key elements for success are good light, adequate humidity indoors in the winter, well-drained potting soil, additional nutrients, and consistent watering. Take any one of those away and problems can develop. Supply them as indicated below, and you'll be on your way to a beautiful tree!  (Which varieties are best for indoor growing?)
 
Light
Citrus require 8-12 hours of sunlight each day to be healthy and productive. A South or Southwest facing window with unobstructed light is generally ideal.  Citrus trees do not go dormant in winter and will tolerate slightly lower light conditions during this period of slower growth. 

If your growing space receives at least 5-6 hours of full direct sun per day, supplementing with full spectrum bulbs or fluorescent plant lights can help trees perform well.  IF, however, the space provides less than 5 hours per day of direct, full sun, more sophisticated grow light systems may be necessary. ACF Greenhouses is a good online source for helpful information about grow light systems.

If you live in an area with cold winters and hot summers, you might consider treating your citrus as an indoor/outdoor plant.
 
Temperature
Citrus grow best between 55°F and 85°F.  They can usually tolerate temperatures down to 32 degrees for 2-3 hours or temperatures over 100 degrees as long as they are well watered.   

Soil
We have found that a light, well-drained commercial soil mix, such as Rose Garden Soil (formulated for outdoor use) can work well. Some experts make their own mixes using wood shavings, sand, and compost.

Using dirt (native soil from your yard) in a container is not advisable. We also advise against putting gravel or any other material on the bottom of the pot, as this negatively impacts drainage over time.

Soils that are too heavy can be amended with about 1/3 – ½ volume of 1" redwood shavings or cedar hamster bedding. Pine and spruce shavings tend to break down more quickly, so are not ideal.  Try to select hardwood chips that will last longer. If necessary, moisten the mix to reduce dust and make it easier to handle. 

Be sure to apply a good fertilizer as appropriate.
 
Water
Water as needed to keep soil moist, not soggy. Generally 1/4 - 1/2 gallon of water every 5-7 days indoors is adequate. Be sure the bottom of the pot is elevated above standing drainage water. A moisture tester can be an excellent tool to help determine when roots are in need of a drink.  Because most commercial moisture testers rely on an electrical conductivity method, however it is possible to get miss-readings due to high salinity or other conditions.  An alternative method recently shared by a New England citrus enthusiast simply employs a plain wooden dowel about the diameter of a pencil.  Sharpen it with a whittling method (sharp knife) or pencil sharpener.  Then insert this into the pot at varying depths, shallow to deeper, determining moisture using your direct senses (feel, smell, etc.). 

 
Humidity
In winter months, heated rooms may need additional humidity. Placing the pot on pebbles in a saucer will elevate the tree above the drainage area, and improve air flow and humidity for citrus.  Misting citrus foliage with a simple spray bottle is another way to help citrus cope with insufficient indoor humidity in winter.

Enjoy!
When you provide these essential elements of success for indoor growing, you'll enjoy a fragrant, ornamental, and delicious houseplant unlike any other!

Please see our Growing Citrus in Containers page to review more helpful tips for successful citrus growing.