The Meyer lemon (Citrus x meyeri) tree rewards you with fragrant flowers and juicy lemons if you provide it with the right care. As an added bonus, it adapts well to life in a pot so you can grow it in even the frostiest of regions by overwintering it indoors. A Meyer lemon tree grows outdoors year-round in U.S. Department of Agriculture plant hardiness zones 9 through 11.
Overwatering a Meyer lemon tree to the point where you kill it isn't hard. To avoid this, allow the top 2 to 3 inches of potting soil to dry out between waterings. Sticking your index finger into the potting soil near the roots is a simple way to test the soil moisture. When you water, soak the potting soil and roots thoroughly until water starts to seep out the drainage holes. If you have the pot in a saucer to catch excess water -- a good way to save surfaces indoors -- empty it after watering.
Feed a potted Meyer lemon tree every other month with citrus fertilizer, for example a 7-3-3 slow-release formula. Use 9 tablespoons for a 24 inch pot, or 3 tablespoons for each 8 inches in container diameter. Sprinkle the fertilizer evenly on the soil -- being careful to avoid the leaves and flowers -- then water. Scheduling the fertilizer to coincide with one regular watering so you don't accidentally overwater. Fertilize from spring through fall and then stop through the winter.
In mild climates where temperatures rarely drop below 40 degrees Fahrenheit, a potted Meyer lemon tree can stay outside year-round. In colder areas, bring the pot indoors in late fall -- before temperatures drop below 40 F -- and return it to a sunny spot outdoors in spring. Keep it in a cool room with bright light through the winter. Pick a spot in a sunny south-facing room away from heater vents and icy drafts.
Pests and Problems
Check the flowers and leaves weekly for aphids, spider mites and other sap-sucking insects. Aphids are tiny insects that may range in color from black to pale green or even white, depending on the species. Spider mites are minuscule and detectible by the fine weblike materials they leave on the leaves and flowers.
Keep an eye out for scale insects, identifiable by the raised lumps on branches that flick off easily. Mealybugs, white insects that look like cotton wool can also present a problem for a container-grown Meyer lemon tree.
Use a neem oil based spray to treat insect problems on a potted Meyer lemon tree. Mix 2 tablespoons of neem oil with 1 gallon of water and spray the lemon tree every seven to 14 days until the pests disappear.
Avoid getting neem oil pesticides on your skin or in your eyes. Once the container is empty, drill a hole in the bottom -- so no one can refill it -- and throw it away.
Every two to four years a Meyer lemon tree outgrows its container. To repot, slide the tree out of the current pot and pot it up in a container that is 1 inch larger in diameter. Make sure it has drain holes or you risk overwatering and killing the tree. Potting soil designed to drain well -- such as a cacti and succulent blend -- works well for moisture-sensitive Meyer lemon tree roots. Leave about 1 inch of space between the lip of the pot and the root ball and set the root ball so the soil comes up to the base of the trunk.
Pruning and Trimming
Keep a Meyer lemon healthy and full with an annual trim in winter. Prune out leggy branches and shape the canopy using a pair of pruning shears. Dip the shears in a solution of equal parts rubbing alcohol and clean water to sterilize after pruning.
As the tree starts to produce fruits, select five to eight lemons to keep and pluck off the rest. Allowing too many lemons develop will stress the tree and reduce the quality of the lemons.