by Erin Marissa Russell
Want to grow your own orange trees, either from seeds or from saplings? Mature orange trees can stretch to heights between 16 and 32 feet. There’s also a smaller dwarf variety of orange tree that stays between eight and 12 feet tall. Glossy evergreen foliage becomes dotted with white dogwood-like blossoms not on a yearly schedule but whenever the weather has been warm or plenty of rain has fallen.
Orange trees can bear fruit prolifically even when just one tree is planted, because they are self-fertile. Trees usually begin to produce fruit after three to six years of growth. The result is a crop of the familiar orange, with its bright, leathery rind and sweet, juicy sectioned interior. Unlike some fruit trees, orange trees may display flowers and fruits simultaneously. The fruit may need up to six to eight months to ripen.
Growing Conditions for Orange Trees
Orange trees are best suited to tropical or subtropical climates, so they can only be kept outdoors year-round in USDA hardiness zones 9 through 11. To grow orange trees outdoors, the growing season should have temperatures between 55 and 100 degrees Fahrenheit, while winter temperatures should stay between 35 and 50 degrees Fahrenheit. In an unexpected cold snap during their dormancy, orange trees can stand temperatures as low as 25 degrees Fahrenheit for up to 10 hours.
However, in less-than-tropical areas, it’s possible to overwinter dwarf orange tree varieties indoors when they’re grown in containers. A young dwarf orange tree of two or three years needs a five-gallon container (about 12 inches wide), while more mature dwarf trees can step up to pots 24 inches wide and 18 to 24 inches deep.
Choosing Locations for Orange Trees
Orange trees need to be planted in a location that gets full sun (from eight to 12 hours of bright sun each day). In places that experience high winds at any point in the year, care must be taken to protect orange trees, especially when they are young. Wind protection can come from bracing a tree with staking, choosing a location that blocks the wind from the tree, or covering trees when winds are high. Regular maintenance, such as proper pruning and access to the water their size requires, can help make orange trees more resistant to wind.
You’ll also need to consider what might be beneath the ground before you dig. Damaging utility pipes or power lines when you garden can come along with hefty fines. Before you break ground, call 811 to make sure the location you’ve chosen is safe. To find out more and get contact instructions for your area, visit the Common Ground Alliance damage prevention website and choose your state from the map.
Meeting Soil Needs of Orange Trees
To really thrive, an orange tree depends on loamy soil. If you aren’t sure what type of soil your garden has, you can try this simple soil test that uses a regular Mason jar. Additionally, orange trees need soil with a pH level in the slightly acidic to neutral range (between 6.0 and 7.5). There are several ways to test the pH level of the soil in your garden or have it tested by others. Soil can be made more acidic with sulphur or less acidic with lime.
The soil where an orange tree is planted should be well-draining, though building up a mound to plant the tree in can relieve some level of bogginess in wetter areas. Some gardeners also recommend mixing in a sandy soil, such as potting mixes for succulents and cacti,, palms, or especially for citrus, to help trees get plenty of drainage.
Citrus trees are known for their fussiness about wet feet. You can check a potential planting location for adequate drainage by digging a sizable hole and filling it with water. If the water is still standing half an hour later, more drainage is needed, and another spot should be selected or soil should be mounded to bulk up drainage.
Citrus trees do not need mulch around them, so if you plan to put your orange tree in a bed that’s covered in mulch, give the tree at least 12 inches of mulch-free space in which to grow. Also adjust to give orange trees planted in mulched areas less water than they would otherwise require, as mulch keeps evaporation levels down.
How to Plant Orange Trees from Seeds
Save the seeds from orange fruits and soak them in clean water overnight. Plant the next day in moist potting soil at a depth of half an inch. Cover the seedling with plastic wrap or a plastic bag to create a miniature greenhouse effect, then grow in a sunny location (ideally a southern-facing window) for a few weeks. When the seedlings begin to sprout, remove the plastic covering and replace the plant on the sunny windowsill.
Orange trees planted in groups should be spaced at a distance of 12 to 25 feet, or set dwarf orange trees at least six to 10 feet apart. Plants may be established outdoors in the springtime or, in warmer zones, in the fall. They may benefit from a gradual introduction to the outdoors, also known as hardening off. Simply carry their containers outdoors, or follow the instructions below for planting saplings if your location is warm enough for orange trees to stay outside during the winter.
How to Plant Orange Trees from Saplings
If you want to start seeing fruit from your young tree immediately, choose a sapling that’s two or three years old. After you’ve chosen the perfect location, dig a hole that’s at least twice as wide as your tree’s root ball. Position the tree in the hole you’ve dug, making sure the root crown (where roots and trunk meet) sits higher than ground level to allow for some soil settling. Around the tree, fill the hole with soil, then water well. Ideally, the fill soil will already be amended with conditioner or organic material, but amendment can be completed gradually as long as plenty of sun and drainage are available from the very beginning.
Care of Orange Trees
Once your orange trees are planted, your job as gardener has just begun. To perform their best, orange trees need regular fertilization, consistent watering, and pruning. They may also need to be moved inside during the winter if it gets too cold for them in your area.
Nourishing Orange Trees with Fertilizer
Provide orange trees with a balanced fertilizer like 6-6-6 or cottonseed meal a few weeks after planting and during the years they do not bear fruit. Better yet, fertilizer blends created especially for citrus trees are available that will have ingredients tailored to what orange trees need to grow productive and healthy. Supplements to maximize health of an orange tree include calcium, magnesium, phosphorus, potassium, and nitrogen. Depending on your soil’s makeup, orange trees may also benefit from micronutrients like zinc, iron, or manganese.
Orange trees growing in containers need to be fertilized more frequently—about every two weeks during the growth phase. Follow the directions on the products you choose for the most exact guidelines on when to apply fertilizer. Less nutrition will be needed in fall as growth slows down and winter when the tree is dormant. Apply these amendments by scratching them into the first few inches of soil around trees.
Watering Requirements of Orange Trees
The University of Arizona Cooperative Extension provides a table of water requirements, listed by month, for orange trees with canopies that measure between two and 30 feet on page two of the linked PDF. Watering is needed every seven to 28 days, depending on tree size and time of year.
Dwarf orange trees should be watered weekly to a depth of three feet when planted in the ground. When grown in containers, dwarf orange trees should be watered twice a week down to the first six inches. Let standard trees dry to six inches and dwarf orange trees dry to two or three inches before their next watering to prevent soil-borne diseases that thrive in overly wet conditions.
Do become familiar with the orange tree’s preferences, as their distaste for overhydration calls for a light touch in watering. Infrequent, deep irrigation will suit orange trees best. Avoid evaporation of this moisture as much as possible by watering in the evening when the sun has dipped past the horizon to make the most of the water you provide.
Falling Fruit: The June Drop
Some trees depend on the gardener to thin out their fruits to avoid overspoilage, but not oranges. Orange trees do not need to be thinned out, as the tree will cull its fruit in the June drop during the postflowering stage, when fruits are still immature. Gardeners should not be alarmed or crestfallen at the sudden avalanche of young fruit falling to the ground during the June drop, which can actually occur in either May or June.
Harvesting Oranges From Trees
After the fruit has become ripe (which can be up to six to eight months), it is ready to be picked. This normally happens between November and March, with ripening happening earliest in the warmest zones. Gardeners should avoid the temptation to pick underripe fruits, instead exercising patience to enjoy every fruit at its tastiest. Fruit will not continue to ripen once it has been plucked from the branch. Oranges are ripe when they taste good and fruit detaches easily from the tree. Ripe fruit can be trimmed off the tree with clean shears or simply pulled by hand.
Pruning Orange Trees
Prune orange trees planted in the ground (again, with clean shears) at the end of winter, between February and March. Remove branches that tangle the canopy’s interior too thickly so sunlight can reach into the tree and make the most of its space. Trim to avoid having branches that cross over one another as well. Pruning is required for orange trees to bear plentiful fruit, as the oranges will only appear on areas of new growth. Very large trees may need tools more vigorous than pruning shears, such as a saw or chainsaw.
Trees housed in containers will require more frequent pruning—several times a year. When pruning a potted orange tree, clip each new shoot at about half its length. Always make cuts on the branch in a place that’s just above a leaf. Be sure to remove any dead areas, and thin out the interior to allow plenty of sunlight to reach in.
Repotting Orange Trees in Containers
If your orange tree is grown in a container, repotting every two or three years is a must as the plant increases in size and uses up the nutrition available in the soil. It’s best to transplant orange trees in the springtime after harvesting fruit or at the end of summer before flowers appear.
When repotting an orange tree, trim around the root ball with a bread knife or other cutting tool to remove five centimeters of roots on all sides. Use a soil blend of one part sandy soil, such as a cacti/succulent blend, and one part plant-based soil without chalk or a prepared blend tailored to the needs of citrus trees. The pot must have drainage holes to ensure the tree doesn’t stay too wet.
Overwintering Orange Trees
Orange trees must be brought indoors for the winter before the first frost in areas where temperatures get too cold. It’s easiest to care for orange trees in these areas when they’re grown in containers, as the plants can simply be moved indoors. Keep orange trees indoors for the winter in a room that gets lots of bright sunlight and plenty of circulation. A grow light can fill in for the sun if a bright enough location isn’t available.
Ensure the temperature doesn’t drop below 41 to 43 degrees Fahrenheit. It’s best to avoid areas that are too warm, so a bright mudroom, patio, shed, or nonheated greenhouse may be just the right spot. It’s important not to allow the trees to freeze over the winter, or you stand to lose the fruit that will be ripening during this time. The orange trees can be moved back outside in the spring in their containers once nighttime temperatures stay above 55 degrees Fahrenheit.
Gradually re-introducing orange trees to their outdoor spots in a process similar to hardening off new seedlings can make the transition easier. Basically, gardeners can stretch out the process of moving back outside by stepping up the time plants spend outdoors each day while at the same time decreasing the protection trees get from the elements, whether that protection comes from shaded areas, blockades that bear the brunt of wind gusts, or simply the isolated time the trees spent in their overwinter indoor home. This process may be employed when trees are coming inside for the winter as well to avoid shocks that can stress the plants or scorch leaves with sunscald.
Garden Pests and Diseases of Orange Trees
The plants will send you signals if they encounter some of the most common problems gardeners of orange trees face. Trees with curled leaves are signaling they’d like more hydration. Yellowed leaves on an orange tree can mean a chelated iron supplement is needed, or they can indicate another nutritional need or a too-extreme drop in temperatures. To address all potential deficiencies, treat orange trees that have yellow leaves with blood and bone, citrus food, iron chelates, and sulphur.
The tiny but formidable aphid comes in several varieties that vary in shade, but all are tiny. A proliferation of tiny insects and leaves that are curling, distorted, or dried up indicate aphids feeding. Treat with a spray made of half a teaspoon of dish soap mixed into a gallon of water.
Citrus Gall Wasps
Signs of citrus gall wasps on your orange trees mean an infestation nearby has spread to you. Overfertilizing plants in winter or spring can result in a proliferation of new growth, which attracts the citrus gall wasp. When citrus gall wasps are a threat, you’ll begin to see the distinctive woody gall that surrounds their larvae on the young, green twigs of your trees. These begin to appear in April and are easily visible in June. Adult wasps emerge from the galls to lay their eggs between September and November.
Remove galls whenever you see them regardless of the time of year. Leave them in a double layer of sealed plastic bags in a sunny spot for at least a month to kill the insects before you dispose of them. June is the best time of year to perform a scheduled check of new growth for citrus gall wasps and treat for them if they’re discovered. Prune to remove branches infested with citrus gall wasps by June 30 each year. If you see more galls after June, repeat removal and solarization, or simply burn the debris and bury it deep.
You’ll know citrus leafminers have moved in and are chomping away at your orange trees when you see the telltale wavy tunnels they carve in the leaves. Only the larva damage plants. Citrus leafminers are most common when temperatures fall between 70 and 85 degrees Fahrenheit and relative humidity is at least 60 percent, making them a struggle coastal gardeners face from summer to fall.
The small moths measure a quarter of an inch long and have white bodies and silver-white wings with brown and black markings. The adults lay eggs within leaves, and those waving tunnels mark the path of hatched larva eating and leaving a trail of frass behind them. When larva mature, they emerge from the mines and wrap themselves in the leaves to pupate for one to three weeeks, resulting in rolled, distorted leaves on the tree.
Gardeners are advised to let the citrus leafminer’s natural enemies control the population instead of using any proactive treatment methods. Commercial traps can aid in detection but do not trap enough specimens to be effective, and they impact the population of beneficial insects as well. Understand that though citrus leafminer larva can reduce growth in young plants, it’s rare for citrus leafminer to kill a tree. Damage may be noticeable for a year or two when trees are young while biological controls kick in.
Crown, Collar, and Root Rot
These rots can be devastating to orange trees, causing discoloration or dropping of leaves and destruction of feeder roots year round. Impacted plants are unable to take in enough water and nutrients, resulting in poor growth and fruiting. Prevent crown, collar, and root rot by being careful not to overwater orange trees and by ensuring adequate drainage.
European Brown Rot
The fungus behind European brown rot causes fruit to soften, turn gray, and decay. The wrinkled, rotten fruits must be removed from trees to treat this disease. Prevent by avoiding wounds to orange trees and applying wound-treating paste if they occur as well as burning trimmed leaves and fruit in the fall and again in winter when the disease strikes Prune affected trees extra well, as fruits that touch can help spread European brown rot.
Fruit flies lay their eggs in rotting fruit, so being careful to remove any fallen oranges that are going bad is your first line of defense. Fallen fruit should be removed for composting daily in summertime. You can also add flowering groundcovers between fruit trees to encourage fruit fly predators to move in. If traps are needed, apple cider vinegar or another sweet liquid in a container the flies can enter but not escape can be hung from tree branches.
White, cottony spots can indicate an infestation of mealy bugs. Yellowed or curling foliage signals a serious problem. Avoid excessive watering or too much fertilization, and consider isolating affected trees to prevent spread. Natural predators such as the lacewing, ladybug,or mealybug destroyer can help you fight back. Alternatively, blast trees several times with a high-pressure jet of water. Use a Q-Tip soaked in rubbing alcohol to wipe off any remaining insects, or you can treat with a neem oil mixture.
Scale insects don’t really look like insects, so they can be easy to miss. They look like brown, green, gray, or black bumps between an eight and half an inch long. Early spring is the best time to apply treatments to prevent them or control an existing population. This is the time to wrap branches in double-sided tape, changing the wrappings until the scale population has dropped. You can also remove the scale insects by hand or use a scrub brush to knock them from the branches. Light infestations can be treated with neem oil. Lacewings or lady beetles can be deployed to prey on the invaders. Pruning to remove impacted areas will not only be a quick fix, the light and heat it lets in will discourage further infestation. Severe cases may require application of horticultural oil.
Sooty mold is easily recognized by its powdery black residue that spreads across flowers, leaves, and fruit. Whiteflies, mealy bugs, Asian citrus psyllid nymphs, scale insects, or aphids may be at fault. The sticky gel left behind where they suck sap from trees, called honeydew, attracts the spores of the Capnodium citri fungus known as sooty mold as they pass through the air. While the fungus doesn’t feed on plants, it does block sunlight, which can weaken trees. Though this disease is called a mold, it’s actually the result of the invading insects, so treating the insect pests is the way to fight back. The fungus will peel off the tree on its own once the insects have left.
Ants often prey on the natural enemies of the insects that cause sooty mold as they defend their right to eat the honeydew. You can try placing boric acid baits around your trees to eliminate the ants, allowing beneficial predatory insects to return. You can also manually remove the insects that cause sooty mold with several rounds of high-pressure water, a toothbrush, or by pruning affected areas. In particularly stubborn cases, a horticultural or neem oil treatment applied in a 24-hour dry period may be required.
These tiny arachnids most often take hold in hot, dry areas, inside greenhouses, or in gardens where chemical insecticides have been applied liberally. That’s because harsh insecticides reduce the populations of beneficial insects that prey on pests like spider mites along with the bugs they target. You’ll be able to see the teeny red or white bugs, about the size of a period ending a sentence, on the undersides of leaves, along with their cottony webbing. White and brown spots may also appear on leaves, or foliage may shrink, become discolored, or fall from the tree.
Quarantine an orange tree with spider mites right away to reduce the potential for spread. First, remove the webbing the mites use to travel. You can blast affected plants with water from a high-pressure garden hose several times to knock the insects off. Examine leaves carefully to ensure the spider mites have all been removed before returning to the garden, or follow with another treatments. Natural enemies, such as predatory mites or ladybugs, may also be deployed.
Gardeners can also create their own gentle insecticides right at home. Mixtures effective on spider mites include sprays made with neem oil, miticide, or insecticidal oil. For example, one home remedy uses one teaspoon of neem oil diluted in one liter of warm water, combiined with four or five drops of dish soap. Use this treatment every 10 days, stopping use three weeks before harvest to prevent the neem oil’s taste from transferring to fruit.
There are three strains of the citrus tristeza virus, each causing a different symptom: quick decline, stem pitting, and seedling yellows. Infected plants may also produce a scanty harvest, grow small or misshapen fruit, or bloom at the wrong time. The citrus tristeza virus is spread via aphids, so treating for aphids (just scroll up to their section) is best. However, infected nursery stock and other human methods of spread are possible. Sour orange trees are especially vulnerable.
Videos About How to Grow Orange Trees
We’ve given you all the information you need to plant and care for orange trees successfully and enjoy a bumper crop of oranges. Just in case you’re looking for more orange tree tips, though, you can check out the videos below.
How to: Grow Orange Trees from Seed (A Complete Step by Step Guide)
7 Tips to Grow Lots of Oranges
Orange Tree Advice
How to Grow Orange Trees from Seed – The Easy Way
Getting 300 Oranges Off a 4-Foot Tall Tree
Want to learn more about how to grow orange trees?
Department of Primary Industries and Regional Development’s Agriculture and Food Division covers Citrus Gall Wasp Control
The Old Farmer’s Almanac covers Growing Lemons and Oranges
Gardener’s Supply Company covers Fruit Fly
Garden Guides covers How to Grow Orange Trees
Gardening Channel covers Stem and Root Rot
Martha Stewart covers How to Grow Citrus Indoors
Modern Farmer covers How to Grow Citrus Indoors