With sweetly scented flowers and sweet-tart flavor, Meyer lemons are a no-brainer for container gardening in the Northwest.
Even though they are not cold-hardy in any but the warmest climates (USDA Zones 9-10), Meyer lemons have many fans. A cross between a traditional lemon and mandarin orange, Meyers are sweeter than regular lemons and prized by cooks and bakers.
Other citruses that come in dwarf varieties can also be grown in containers, but Meyer lemons are by far the most popular. They’re also the easiest to find at nurseries and through mail order.
When choosing a pot for your plant, lean toward larger over smaller, but keep in mind you will have to haul it in and out of the house or greenhouse. Start with a 5-gallon container and repot up to first a 15-gallon pot and then one that’s 25 gallons as your tree grows.
The most important factor to growing Meyer lemons—or any citrus—is to bring them inside when danger of frost looms, usually around Halloween. Return them outdoors in mid-April. You don’t want big temperature variations for your tree, so spend a few days hardening it by taking it out during the day and returning it to its indoor spot at night. Keep the tree in shade for the first week, but remember citrus needs full sun to bloom and fruit.
Inside, place the plant near a bright window with six to eight hours of sunlight. A south-facing window usually provides that. A temperature of 65 F at night is best. Don’t keep the tree near a vent; it doesn’t like hot air blowing on it. Always give your tree a bath before bringing it inside for winter to help prevent pests.
Meyer lemon trees, which grow in the 3- to 4-foot range in containers, are self-fertile, so they don’t need another tree for pollination. However, they do need insects or wind to move that pollen around, so if you keep your tree inside too long, you likely will get fewer fruits. Hand pollination is an option. Just use a small paintbrush to transfer pollen from flower to flower.
The tree won’t need much pruning, but dead or crossing branches must be cut. If the foliage inhibits air circulation, thin out the center of the tree.
In summer, when your tree is outside, water it once a day. Let the water drain through so the roots don’t sit in it. Water less often in winter. Stick your finger in the dirt up to the second knuckle. If your finger is dry, water the tree.
Fertilize in summer with a citrus fertilizer or one labeled for rhododendrons and blueberries. All three like acidic soil. Cut back or discontinue feeding in winter.
People are distraught when they see flower, fruit or leaf drop, which can result from not enough water, cool night temperatures or fluctuating temperatures. Meyers are usually disease-free, but there are three pests that plague them: scale insects, aphids and spider mites.
Aphids are the easiest to control. Wash them off with soapy water, and rinse with a hose. Treat spider mites with a houseplant insecticide labeled safe for food crops.
Scale insects are more problematic. If you catch them early, crush them with your fingers, then wash the plant with soapy water, rinse it and take off the topsoil. Once scale get established, it’s a more difficult proposition. At that point, many people discard their plant and start over.
Information courtesy of Oregon State University Extension Service.