By Deborah J. Benoit
Extension Master Gardener
University of Vermont
When the long wait for spring gets you down, would the scent of lemon blossoms lift your mood?
Well, you don't need to hop a plane to Florida. You can grow citrus right in your home, no matter where you live. The trick is choosing a dwarf variety suitable for growing in a container.
Meyer lemon (Citrus x meyeri) is a popular, easy-to-grow choice, but a variety of citrus plants are available by mail order or through a nursery. If you shop locally, you often can find a plant in bud or bloom. Whether you choose a Meyer lemon, a Persian lime (Citrus x latifolia) or some other dwarf citrus, with little more effort than required for other houseplants, you can enjoy the sweet fragrance and, ultimately, fruit.
Citrus enjoys temperatures between 50 and 85 degrees Fahrenheit, with temperatures around 65 being ideal. During warm weather your citrus will do best outdoors. Avoid windy locations or anywhere your plant might be subject to standing water.
When the weather turns colder, bring your citrus plant inside. First, move it to a shaded area outdoors, then onto a porch, and then indoors. By gradually acclimating it to less sun, you reduce the chance of adverse effects from the change in conditions from outdoors to in. This same process should be followed in reverse when moving your plant from inside to out in summer to avoid sunburn damage to the foliage.
Your citrus plant needs plenty of bright light, around 8 to 12 hours daily of sunlight or sunlight supplemented with grow lights.
Thoroughly water your citrus plant once or twice a week when the first inch or so below the soil's surface feels dry. Citrus prefers moist, but not wet, soil. Never allow the pot to sit in water or dry out completely.
During spring and summer feed your plant about once a month with a fertilizer that's high in nitrogen. Fertilizers specifically formulated for citrus trees are commercially available. Be sure to follow directions on the package.
Indoors, dry air can be a problem. To increase humidity, group other houseplants nearby. You also can fill a tray of small stones with water and place the pot on top of it, being careful the water doesn't reach the bottom of the pot. Ideally, you might consider investing in an ultrasonic humidifier that will help humidify the entire room.
Repot every few years. Choose a pot deeper than it is wide and that has several drainage holes. You'll want to use a light potting mix that will drain well. Avoid additives that retain moisture.
Although you can buy citrus potting mixes, any well-drained commercial potting pot mix can be satisfactory. Be sure the graft union (where the citrus plant is joined to the dwarfing rootstock) is above the soil line when repotting. Water the potting mix thoroughly after repotting.
Container-grown citrus is likely to bloom in spring, though buds can appear year-round, even when fruit is already ripening on the plant. You won't need another citrus plant to cross pollinate to produce fruit, but you will need to give the flowers a little assistance. You can gently shake the plant to encourage pollination. Using a cotton swab to pollinate the flowers also works well.
Soon after, tiny, green fruit should appear. Don't be discouraged if some drop. There may have been more flowers pollinated than the plant can support, or it may be stressed due to moving from one location to another or too much or too little water.
Fruit typically matures in 6 to 9 months although some, such as oranges, take up to a year. Once the fruit has ripened, it can remain on the citrus plant for some time before picking.
Deborah J. Benoit is a UVM Extension Master Gardener from North Adams, Massachusetts, who is part of the Bennington County Chapter.