Updated: Oct 29, 2019
Citrus plants may grow outdoors year round in warm climates but in our Northern climate you can grow citrus plants indoors successfully.
Citrus plants make attractive houseplants, with their glossy dark green leaves and when in bloom they add a beautiful scent to the room as well. If pollinated the flowers will produce edible fruit, which is an added bonus.
First step is choosing smaller sized varieties that are more suitable for growing indoors. Lemon, lime, and calamondin oranges are smaller sized plants that grow 1-1.5 meters high. The care for growing citrus plants indoors is the same as looking after a tropical houseplant. Citrus plants require lots of light. They do best when placed in a south-facing window, where they will receive at least 6 hours of daily, direct sunlight. If light is an issue, a full spectrum light placed over the plant can be helpful.
They enjoy warm even temperatures of around 20 Celsius. They can handle cooler evening temperatures, but avoid placing them anywhere near an outside door, draft or heating vent where there is a sudden temperature change, which can cause the foliage and fruit to drop. Over the summer months when all risk of frost has passed, citrus plants can be placed outdoors on a deck or patio. If you plan on putting the plant outdoors throughout the summer, acclimatize it first by placing it outdoors in a shaded spot for a few hours and then bring it in at night. Do this for a couple of weeks, allowing the plant to stay out longer each day, so that the plant slowly get used to the outdoor temperatures. At the end of summer, bring it indoors before the first frost.
Humidity plays an important role in a citrus plants health.
This can be challenging in our area, as we tend to have low humidity. If you don’t have a humidifier, placing the plant on top of a water filled pebble tray, keeping the plant above the drainage area will help, as the moisture evaporates around the plant, raising the humidity. Another option is misting the plant daily. Low humidity can result in dropped leaves
Water the plant as needed, and not on a schedule. When the top 5 cm of soil feels dry to the touch, it is time to give the plant a thorough water, using room temperature water. Allow the water to soak through to the bottom of the plant and drain away any excess water from the the drainage saucer. Keep the soil moist, but avoid keeping it soggy. Soggy soil can lead to root rot which will eventually kill the plant.
Citrus plants are heavy feeders and need a fertilizer that is higher in nitrogen and lower phosphorous and potassium. Some people like to use rose food. Fertilize regularly, more so during the spring and summer when the plant is actively growing.
When the plant has become root bound it can be re-planted into a container one size bigger than the container it is currently in. Ceramic or clay containers with drainage are ideal. Use a high quality, all-purpose potting soil. Don’t transplant when it is in bloom or bearing fruit.