Citrus trees are tropical or sub-tropical trees that are very sensitive to cold. Most citrus trees will not tolerate frost or freezing temperatures. Citrus, like many other trees, require full sun and need a lot of water. With proper care, your citrus trees can produce fruit for generations.
All citrus trees require lots of sun for proper growth. However, if you are growing citrus in containers, you can bring your container-based tree into partial shade in preparation for bringing the tree inside for the winter. In areas where you don't need to bring your trees inside for the winter, however, try to keep your tree in full sun with no shade.
Water your tree several times a week when young, and at least once a week after the first year. Give your tree between three and seven inches per week. Adjust the amount if the top inch of the soil is drying out too fast. Try not to let more than the top inch of soil to dry out between waterings.
Citrus trees require more fertilization as they age. Use a water-soluble fertilizer and be careful not to over-fertilize your citrus trees. Carefully follow manufacturer's label instructions for the variety of tree you have and the planting location. You may need to fertilize potted trees more often than trees planted in the ground.
Prune your citrus in the late winter when it is dormant. By pruning at this time, you will damage the tree less because it will not be expending energy for growth. Prune your tree by making cuts at around a 45-degree angle with very sharp pruning shears or saws, depending on the size of the branch you wish to remove. Prune dead wood from the tree at any time, but be mindful of taking too much live wood outside of the winter pruning season.
If you are growing your citrus in containers and expect a hard freeze, move your pots inside. If you are growing your citrus in the ground, gently drape blankets and quilts over the tops of the trees and seal in their existing warmth. If necessary, use incandescent bulbs or propane heaters to keep trees and groves from freezing.