Growing Citrus Indoors

It seems every year we get the shipment of limes and Meyers lemons into the garden center and folks go into a buying frenzy. And you know what? They have every right to do so. There is nothing like a fresh picked lime or lemon to use in food preparation or making your favorite beverage. The taste and amount of juice you get from your homegrown citrus trumps store bought ten-fold. Tip: Limes are not ripe until they are pale yellow. What you’re buying in the grocery store are “unripened” limes.

So….you bought that lime or lemon back in the spring and it’s time to figure out what to do with it while Ol’ Man Winter gets ready to make an appearance. Bring it inside of course. Growing citrus indoors is possible and easy as long as the key elements are adhered to.

First of you should inspect your plant from top to bottom. Top and underside of leaves, branches, main stems and the trunk. Look for those unwanted pests that are not invited to share the warmth of your home. Scale, mealybugs, aphids, spider mites. Spray the plant with insecticidal soap or horticultural oil. I would do it at least twice at 4-5 day intervals and if you do bring the plant in before doing this, keep it in quarantine until you’re sure it’s pest free. I would also get a product called Azamax – which is organic – and do a soil drench on the same schedule to kill off any unwanted pests that may be living in your soil. You can make your own soap mixture if you wish. Get some Murphy’s oil soap and use 2 tbsp. per gallon of water and you are good to go. Do NOT use Dawn or other soaps. They have a tendency of removing the protective coating from leaves leaving them open to all kinds of problems.

So now what? Well let’s make sure the plant’s need are being met:

Light: To be healthy and productive citrus needs 8-12 hours per day of direct sunlight. A south or southwestern facing window would be ideal. Citrus can tolerate some lower light levels but they never go dormant in winter. While florescent lights can be used to give the additional light a plant needs if you really want to keep production going consider a Metal Halide or HPS. I personally use a 400 watt HPS which has Angie and I picking lemons and limes all winter. And to walk down to the family room and get hit with the citrus flower fragrance is pure heaven.

Temps: They prefer to be in the 55 to 80 degree range. They can tolerate being down to around 32 degrees for a few hours and upwards of 11 if kept watered. I did make the mistake last spring of leaving our lime out one night and it went down to 29. The plant survived but don’t think they all will. Be safe and not like Jimmy and bring it inside when temps start to dip below 50.

Soil: A good draining soil is a must. Espoma has a cactus soil which can also be used with citrus. If you wish to do your own, mix some redwood or cedar shavings into the mix to help aerate and provide proper drainage. Pine and spruce have a tendency of breaking down quicker. Do not add gravel or other material to the bottom of the pot as it affects the drainage over time. Japanese bonsai artists have proven this.

Water: On average your plant should be watered every 5-7 days. Take a dowel, chopstick or bamboo skewer and insert it at different levels into the pot. This will help you judge moisture levels and give you an idea when your plant needs a sip of H2O. Fill a container with water and let it sit out for at least 24 hours before watering. This allows the chlorine to dissipate as well as bringing the water up to room temperature reducing shock to the plant.

Humidity: Citrus likes it humid and unfortunately the drier air in the winter home is not sufficient. A tray with pebbles and water will help raise the humidity level as well as grouping your plants together. A spray bottle can be used to mist the plants. Some folks use a humidifier but be careful where you use it because mold/mildew can become a problem especially with older homes.

Fertilization: I love using Espoma Citrus-Tone. It’s specifically designed to meet the nutritional requirements of citrus plants. If you want to use a water based fertilizer Sea-Mate is the way to go. You can find both at your local garden center.

So there you have it. Provide the essential key elements and you’ll have a fragrant houseplant that will provide you with fresh fruit.