As a gardener, I’m always tempted to try something new to challenge my skill set. You might say I’m always reaching for the fruit hanging just out of reach. For most parts of the United States, growing lemons, limes, and oranges is very far out of reach. Cold climate, poor soil conditions, lack of sunlight, and limited yard space can keep you from trying to grow citrus. But raising a dwarf citrus tree inside a pot will make the dream of homegrown citrus more attainable.
Adding your own lemons to a beverage or salad is a thrill. It’s very rewarding to see your own citrus in a jar of marmalade or floating in a glass of lemonade. Fresh lime leaves for your Thai stir-fry can be just a few steps away from the kitchen.
Dwarf citrus trees are well adapted to container growing conditions. In some parts of the country, folks can grow potted citrus outdoors most of the year, while others will need to grow them in a sunny window for all but a few summer months. Citrus is self-fruitful, meaning you don’t need a second tree for pollination. All will bear after a few years, giving you the scent and taste of a warmer climate. The blossoms will fill a room with an alluring sweet scent, and the fruit is bursting with flavor.
Get Serious About Citrus
You can buy dwarf citrus at your local nursery or online (see “Citrus Sources,” at the end of this article). Be sure the tree you’re buying is well-adapted to container growing, such as ‘Improved Meyer’ lemon (Citrus x meyeri) , Thai lime (C. hystrix), ‘Bearss’ lime (C. x latifolia) , Key lime (C. x aurantiifolia), Satsuma mandarin (C. unshiu) , Calamondin orange (x Citrofortunella microcarpa), and ‘Trovita’ orange (C. sinensis). One-year-old trees come in a small pot or may be sold bare-root. Two- to three-year-old trees are usually offered in a larger pot as well.
After you’ve obtained your tree, it’ll need to be potted up. A 10- to 14-inch pot is ample for a one- to three-year-old tree. As the tree grows, you’ll need to increase the pot size to 16 to 20 inches. Don’t put a small tree in a large pot because it’ll be too difficult to regulate soil moisture levels. Plastic pots are the lightest options and it’s easy to maintain proper soil moisture inside them. Clay and wood are heavy and less ideal for managing moisture levels. Choose a pot with lots of drainage holes, or add more holes yourself. Avoid black nursery pots because they may overheat in direct sunlight and cause the roots to die. A smaller pot can be nested inside a larger decorative pot for appearance and to provide some insulation from excess heat.
Citrus Soil Requirements
Citrus require good drainage, so choose a light but rich outdoor potting mix that drains well. Avoid indoor potting mixes because they often contain water-retentive chemical wetting agents and fertilizers. An outdoor rose garden soil mix is ideal. To ensure proper drainage, add 1/4 to 1/3 of the soil’s volume in cedar or redwood shavings or 1-inch hardwood bark chips. Mix it all together thoroughly.
Planting Your Citrus Tree
To plant your tree, first prepare the roots. If the tree is in soil, loosen the root ball. If bare-root, spread the roots, and trim any dead or broken roots. Mix the packing shavings into your soil mix. Put a few inches of soil in the bottom of the pot. Don’t add stones or any material to the bottom of the pot for drainage purposes. Set the tree into the pot, leaving the trunk and the graft line above the top of the soil. The graft line is a slanted scar on the trunk of the tree, usually 4 to 8 inches above the roots.
Add soil to the pot, making sure not to leave air pockets. Watering halfway through the fill will help settle the soil around the roots. Leave a few inches at the top of the pot to make watering easier. Mulch the top of the soil with more hardwood chips or shavings.
A southwest-facing window or sunroom away from frequently opened doors is ideal. Citrus thrives on eight hours of sunlight per day. Some people use grow lights in the shorter winter days, but this is unnecessary if your tree gets a lot of window light.
Watering and Feeding Citrus
Consistent watering is the most critical part of citrus care — too much or too little can kill your tree. Infrequent deep watering is better than regular shallow watering. Wait until the soil is dry 4 to 6 inches below the surface. A soil moisture tester (available at garden centers) is excellent for determining when to water. You can also use a dowel or chopstick to read moisture. Simply insert the wooden rod into the soil, extract it, and feel for the depth at which the wood is moist.
Water the tree 1/4 to 1/2 gallon per week. Never allow the soil in the container to become bone-dry. Citrus also hates wet feet, so place a drainage pan underneath the container that will lift the pot above any standing water.
If the tree leaves are wilted but perk up after watering, you waited too long to water. If the leaves yellow and cup, you’re watering too frequently. Adjust watering for time of year and temperature.
Citrus trees feed heavily on nitrogen. Every few months, they’ll need a small dose of a slow release fertilizer or compost. Choose an organic fertilizer that has NPK (nitrogen – phosphorus – potassium) rates of 2-1-1 or 3-1-1 and contains trace minerals such as iron, magnesium, zinc, and manganese. Follow the rates listed on the package. A fish emulsion with kelp or compost tea is another option. A light application of compost can also be scratched into the soil surface inside the container.
Pruning for Health
A dwarf citrus tree can grow to a height of 6 to 12 feet, but can be pruned to a manageable size. You’ll want to prune branches for shape and balance as your tree grows. Trim off any leggy branches. Any suckers that sprout below the graft should also be removed.
When temperatures permit, your indoor citrus plant can live outdoors. Temperatures must be over 50 degrees Fahrenheit, with the ideal range falling between 65 and 85 degrees. To transition your tree to outdoor living, move it outside for 2 to 4 hours each day for one week before leaving it outside during the warm season. Cloudy weather is ideal for growing dwarf citrus outdoors. Place your pot in a sheltered sunny area that’s protected from wind. Pay close attention to soil moisture and adjust your watering schedule accordingly for this new climate.
Citrus Pest Control
Citrus can get aphids, mites, and scale insects. Watch for sticky spots or signs of insects on the leaves. A household spray bottle filled with water and 1 tablespoon of mild dish soap will rid your tree of most pests. Scale can be removed with a cotton ball or swab soaked with rubbing alcohol. Orange TKO, an organic citrus-based cleaner, is especially effective against mites. Neem oil also works against citrus pests.
The rewards come readily. Citrus trees bear early. A light fruit set can be expected in the second year of growth, and significant yields by years four to six.
Ripe fruit doesn’t drop quickly from the tree, which allows you to spread out your harvest over several months. Many trees will set fruit in spring and again in fall. The winter blooms will fill your house with their delicious scent.
Use your fresh lemon juice in this creamy Meyer Lemon Ricotta Recipe.
Roberta Bailey is a long-time organic gardener who raises and tests seed crops for Fedco Seeds, a worker/consumer-owned cooperative in Maine.