In a full-sun site and well-drained soil, a Meyer lemon tree (Citrus × meyeri) should bear plenty of thin-skinned, golden yellow fruit. In warm climates and in containers indoors, Meyer lemon bears fruit year-round, and in cooler climates new fruit usually appears in late winter or early spring. Meyer lemon is hardy in U.S. Department of Agriculture plant hardiness zones 9 through 11, and grows 6 to 10 feet tall and 4 to 8 feet wide, though containers restrict the tree's size. A young tree might take two to three years to produce fruit. After that, fruits appear for 30 years or longer.
A Meyer lemon tree that isn't producing fruit may be not be receiving enough light. This tree needs eight to 12 hours of sunlight every day to flower and fruit well. If your Meyer lemon is growing in a container, place it in a sunny, sheltered position outdoors year-round if you live in USDA zones 9 through 11. In colder zones, place a Meyer lemon in a container outdoors in a sunny, sheltered spot when frosts no longer threaten.
If your Meyer lemon is growing outdoors in partially shaded or full-shade conditions, remove overhanging foliage that shades the tree, or consider transplanting the tree to a full-sun site.
Protecting From Cold Temperatures
The Meyer lemon tree is among the hardiest of the citrus family, but it stops growing at low temperatures, and frost damages its developing flowers and fruit. Temperatures below 55 degrees Fahrenheit cause a Meyer lemon to become dormant, and the tree doesn't flower or produce fruit until temperatures rise again. Temperatures below 32 degrees Fahrenheit damage the tree.
To protect a Meyer lemon tree from cold temperatures, move a tree in a container to a bright, cool room when nighttime temperatures fall below 55 degrees Fahrenheit. Don't place a Meyer lemon tree in a heated room. If the environment for an indoor tree is too warm, it can lose its leaves. Protect an outdoor tree by covering it with three or four layers of horticultural fleece in frosty weather. Stringing holiday lights through the branches of the tree also offers some protection from frosts.
Watering a Meyer Lemon
Watering a Meyer lemon tree correctly encourages healthy fruits. Sandy, neutral soil or loam provide the best growing conditions for this tree, or a free-draining, soil-based potting mix if the tree is in a container. A container for a Meyer lemon tree must have drainage holes.
Water the tree when the soil surface is dry. Water an in-ground tree until water begins to puddle on the soil surface, then stop. Don't grow a Meyer lemon tree in wet, poorly drained soil.
Water a tree in a container until water flows through the drainage holes. Misting an indoor Meyer lemon tree with a handheld spray mister every other day during winter helps the tree retain its leaves and develop fruit.
Nutrient deficiency can prevent a Meyer lemon tree from producing fruit. Rich garden compost or well-rotted manure fertilizes an outdoor Meyer lemon tree. Spread a 4-inch layer of compost or manure around the base of the tree, but don't allow the mulch to touch the trunk. Top up the mulch when it thins out.
If an in-ground Meyer lemon tree is growing poorly and has small pale leaves, it might be suffering from nutrient deficiency and benefit from a high-nitrogen fertilizer. A cup of ammonium sulfate, split into three applications and applied when the tree is actively growing in spring, summer and fall, supplies the nutrient needs of a 1-year-old tree. Increase the number of cups according to the age of the tree up to a maximum of six cups. Sprinkle the ammonium sulfate over the root zone and water it in. A Meyer lemon that has plenty of lush, green growth isn't suffering nutrient deficiency, and lack of fruit may be due to overfertilization.
A Meyer lemon tree in a container needs applications of a specialized fertilizer three times every year. Apply a granular 6-4-6 citrus fertilizer with added micronutrients when new growth appears in spring. Apply the fertilizer again after 90 days, and again after another 90 days. Sprinkle the granules evenly over the potting soil surface at a rate of 2 1/2 teaspoons per 10-inch container, 5 teaspoons per 14-inch container and 2 1/2 tablespoons per 18-inch container. Manufacturers' instructions vary from product to product, so read the product label and follow the directions.