Many types of citrus trees can be grown indoors in the North. The best way to grow citrus in the North is to keep the pot outside in the summer and bring it in when the temperature goes below 50° F. It can winter in a heated greenhouse or in a sunny window. In pots, trees can be maintained at under 6 feet tall and make productive evergreen edible ornamentals.
Origin: China. Brought to India and then the Middle East and Europe before the time of Christ. Brought by Columbus to the Americas.
Pollination: Our varieties are self-fertile. If you have them inside when they flower, so bees and insects can’t pollinate them, use a water color brush or cotton swab to rub pollen within the flower. Often they produce fruit without doing this.
Hardiness: Most survive brief exposure from 10° to 28° depending on variety. Though plants are evergreen they do go into dormancy and stop growing below 54° F. Growing indoors, at least 70° during the day and 55° at night is best. While they may survive to below freezing, they need the warm temperatures described to do well.
Sun or shade: Full sun or a sunny window. The trees need a lot of light. They benefit from supplementary lighting. Using a fluorescent or a spotlight of incandescent light to extend their light period to 12 hours a day in the winter will help. A grow light will work too.
Size at maturity: Grown in a pot, all can be easily maintained at 4-6' tall.
Method of propagation: Seeds or grafting.
Yield: Grown in a pot, several dozen fruit a year.
How to Grow
Soil requirements: Grows best in a pot with a sandy, well drained potting mix. Trees don’t do well in clay or heavy soils. Fertilization is important and should include trace minerals found in the Organic Citrus Food listed on this page.
Cultural requirements: Most trees will arrive in a long narrow container where they can remain for several months. Water it deeply when the soil is getting dry rather than giving too frequent surface waterings. When you repot the tree, be sure to spread out entangled roots and clip off the last inch of the roots. Place the tree about as deep as it was in the container and keep the graft above the ground. Repot into a 10 to 15 gallon pot. The tree will need root pruning and repotting every four years or so. Plants benefit indoors from higher humidity so mist the tree occasionally. Place a pan of rocks under the pot. Pour water in the pan. This provides extra humidity for your plant.
How to Use
In the kitchen: The sweet citrus is wonderful eaten from the tree and is nice in fruit salad. Both sweet and sour citrus make great juice or marmalade. One or two potted lemon or lime trees can provide for a family’s yearly needs.
In the landscape: Makes a beautiful, fragrant small evergreen house plant. A great plant for the deck or courtyard.