Orange trees are one of the most recognized types of citrus trees featuring full, leafy canopies and fragrant flower displays. Best of all is the delicious fruit produced during the growing season. A full-size tree can grow to 32 feet tall, with dwarf varieties reaching about 12 feet in height. Orange trees can be kept even smaller when planted in containers, which makes them great for indoor gardening as well.
Orange trees are notable for white blooms that appear in summer followed by their famous fruit. These trees can be planted at any time of year in warm climates, like southern Florida where they represent a major food crop. For cooler climates with significant seasonal variations, they grow better when planted in spring or summer which allows them to acclimate before cooler weather arrives. Although the fruit is delicious, the plant itself is known to be toxic to pets.
|Common Name||Orange tree|
|Botanical Name||Citrus sinensis|
|Plant Type||Tree, Fruit|
|Size||30 ft. tall (full size), 12 ft. tall (dwarf), 30 ft. wide (full size), 12 ft. wide (dwarf)|
|Soil Type||Loamy, Well-drained|
|Soil pH||Acidic, Neutral|
|Hardiness Zones||9-11 (USDA)|
|Toxicity||Toxic to pets|
Orange Tree Care
Orange trees require plenty of sunshine and warmth; key factors for producing sweeter fruit. They are susceptible to wind damage so some protection is needed. Since these trees can grow fairly large, depending on variety, space them about 20 feet apart. For dwarf varieties, 10 feet should be sufficient.
Orange trees are self-fertile and do not require another orange tree to produce fruits. However, including more than one orange tree in your garden will attract more pollinators which can increase fruit production.
Orange trees require plenty of sunshine and warmth to produce the best-tasting fruits, so choose a spot that receives full sun for eight hours a day. For dwarf varieties grown indoors, place them in a sunny window.
Orange trees thrive in loamy, rich, well-draining soil. It is important that excess water drains away, as orange trees cannot tolerate heavy, wet soil. When planting these trees, you can mix in potting soil for additional nutrients. Slightly acidic to neutral soil pH levels from 6.0 to 7.0 work best.
Orange trees need consistent watering but don't tolerate soggy soil. Drainage can be improved by building up a small mound at the bottom of the planting hole. Established orange trees do best with about 1 inch of water a week. How often you water will depend on the amount of rainfall you receive.
Temperature and Humidity
Orange trees thrive in subtropical regions with warm temperatures and moderate humidity levels. They can be grown outdoors in USDA hardiness zones 9 to 11 and begin to go dormant when temperatures dip below 50 degrees Fahrenheit.
The optimal temperature to grow an orange tree hovers between 60 and 90 degrees Fahrenheit. This applies to trees in the ground and in pots. However, it does depend on the cold tolerance of the type of orange tree planted. For example, a naval orange tree is not as cold-hardy as a mandarin orange tree.
When grown in cooler areas, orange trees need fertilizer every month or two during the growing season. In warmer zones, such as 10 and 11, fertilizing year-round encourages continual growth and fruit production.
For young trees, start with a small amount of fertilizer, about half-strength. Once the tree matures, give it full-strength fertilizer and spread it out around the tree all the way to the drip line. It is best to use a well-balanced fertilizer, such as 10-10-10, or one specifically designed for citrus trees.
Types of Orange Trees
- Navel Orange: Navel oranges are common varieties often found in grocery stores. They are easily identifiable for their navel-like marking at the bottom of each fruit. This variety is sweet, seedless, and enjoyed both for its juice and as a snacking fruit.
- Blood Orange: Known for their unique red coloring and sweet flavor, these oranges are a popular ingredient in prepared dishes and good for snacking.
- Valencia Orange: Another common variety, Valencia oranges contain a high juice content ideal for juicing. They do have seeds.
- Satsuma Orange: This small, sweet, and cold-hardy orange has fruits with loose, leathery skin, and is better known as the mandarin orange. The tree can take up to eight years to bear fruit.
Harvesting oranges is easy and fun. It depends on the variety of tree you have to know when to pick an orange tree of its fruit. For example, navel oranges are ready to pick between November to June, Valencia oranges are ready to pick from March through October.
Once you determine when it's the best time to harvest your orange tree, look for fruit that is bright and consistent in color, firm with a slight give, and fragrant. Those are ripe and ready to pick and eat. Gently pull them from the branch, or use snips to cut the fruit from its stem. Just be sure it is ready, as oranges do not ripen after they are picked. Store oranges in the refrigerator. They should last a few weeks.
Pruning following fruit harvest will benefit the following season's crop. In the cooler regions of their growing zones, orange trees are best pruned in the fall after fruiting and before cold temperatures arrive. In warmer regions where temperatures are consistent year-round, pruning can be done almost anytime but is most effective before new growth begins in spring.
Pruning for shape is optional but not necessary. It is important to prune away damaged or dead branches and any branches that cross each other. This keeps the tree healthy and provides good airflow and light. For young trees, remove branches that are less than a foot above the ground.
Propagating Orange Trees
Orange trees can be propagated through cuttings. This is best done in the late spring or early summer while the tree is producing new growth. To do this, you need a sharp pair of snips, a pot with rich, well-draining soil, rooting hormone, and a plastic bag. Then follow these instructions:
- Select a branch tip that is around 6 inches long with healthy leaves. Cut the branch below a leaf node at a 45-degree angle.
- Remove leaves on the lower half of the cutting. Remove any blossoms or developing fruit.
- Score the bark with a clean knife near the cut end of the cutting to encourage root growth.
- Dip the cut end into rooting hormone. Shake away access powder.
- Moisten the soil, then poke a hole in the center to plant the cutting.
- Plant the cutting in the hole and firmly press the soil around it.
- Place the plastic bag over the cutting to keep the humidity levels up. Place the pot in a warm area that receives bright, indirect light.
- Allow the bag to breathe daily and check the soil moisture. Keep it moist, but not wet.
- Remove the bag after a week or so and allow the cutting to acclimate to average humidity levels. Keep the soil moist.
- After roots form, move the cutting outdoors to a partially shaded, protected area. This may take several months. Once outside, slowly expose the cutting to more and more sun until it can be planted in direct sunshine.
How to Grow Orange Trees From Seed
Orange trees can be started from seed, though it is important to note that seeds may not produce trees with the same characteristics as their parent plant. If you wish to start a tree from seed, you will need a bowl of water, a tray or small pot with rich potting soil, and a plastic bag. Then follow these instructions:
- Before planting the seeds, soak them in a bowl of water for at least 24 hours. Dispose of seeds that float (they are not viable), only planting those that stay below the water.
- Plant the soaked seeds in the rich potting soil about 1 inch deep.
- Place the pots in a warm area and keep the soil moist. Place the plastic bag over the pot to keep the humidity levels up. Allow the bag to breathe daily, checking the soil moisture.
- Once the seeds germinate, remove the bag.
- Place the seedlings in an area that receives bright light. Grow lights may be needed.
- Repot each seedling into its own container and keep them in bright light.
Potting and Repotting Orange Trees
Dwarf orange trees are popular fruit trees to keep in pots. This is a great option if you live in climates colder than those recommended for growing citrus. A potted tree can be brought indoors before cold temperatures hit. Choose a deep pot made from wood, clay, or even plastic but make sure it has plenty of good drainage holes to accommodate the root system.
Orange trees need to be repotted about every two to four years, depending on your tree. Check for signs that the tree has outgrown the container, such as stunted growth or roots coming out of the drainage holes. Repotting is best done in the spring before new growth appears.
To repot your tree, tip the container onto its side. Tap the outside of the pot to loosen the roots, then grasp the trunk close to the soil and gently slide it out. Place the tree into a container that is several inches larger than the previous one and fill it in with new, rich soil. Press the soil around the tree and give it water.
When orange trees are grown in their appropriate growing zones, not much is needed to overwinter. Simply remove any leftover fruit and cut back on watering. If there is a threat of frost, you may wish to insulate the tree with frost cloths. For trees grown in areas outside their growing zones, you will need to move the tree indoors before heavy frosts begin.
Common Pests and Plant Diseases
Like many fruit-bearing plants, orange trees are prone to specific pests and diseases. Pests that commonly attack orange trees include aphids, scale, spider mites, Asian citrus psyllids, and leafminers.
Different fungal and bacterial diseases can affect the trunk, leaves, and fruit. These include things like citrus canker, citrus melanose, and root rot.
How to Get Orange Trees to Bloom
An orange tree dotted with oranges and delicate white blossoms is a sight to behold. Orange blossoms, Florida's state flower, first show as tight little white buds that unfurl into sweetly fragrant star-shaped flowers each with five waxy petals with orange-yellow stamens.
The best way to ensure your tree blooms is to make sure you are giving it the right amount and type of fertilizer formulated for citrus trees. Though an orange tree needs nitrogen, too much of it can impede your tree from flowering. Trees damaged by a long spell of extremely cold weather or a lack of sunshine will typically not bloom.
Common Problems With Orange Trees
Orange trees can be easy to grow until they show signs of problems. Frequent examination of your tree is usually necessary to mitigate issues. Learn how to recognize when something is potentially wrong with your orange tree.
If the veins of an orange tree's leaves are yellowing, it could be that the tree is not receiving enough nitrogen. Yellowing leaves may also indicate root rot from overwatering. Yellowing leaves may also mean the tree is affected by citrus greening which is a bacteria transmitted by the citrus psyllid. There's no cure for citrus greening, but you can control psyllids with neem oil or other insecticidal soaps.
Small blistering spots that are brown, brown with yellow halos, or cause holes on leaves mean your tree has citrus canker. Use copper fungicides to combat the problem.
Excessive Fruit Drop
Mature orange trees with excessive fruit drop may mean the ground is saturated with water and the tree is stressed, causing it to produce damaged fruit.
The fruit may split its skin during prolonged hot, humid periods. This may also happen when the tree quickly drinks up water after somewhat of a drought period, which can cause fast swelling of fruit and splitting of the skin.
How long can orange trees live?
The average lifespan of an orange tree is between 50 to 60 years, though some have been known to live over 100 years.
How long does it take for an orange tree to mature?
An orange tree will reach maturity when it is six or seven years old. However, it may not take as long for an orange tree to bear fruit. A young orange tree will begin to produce fruit when it is only three to five years old, but the fruit may be small at first.
Are orange trees hard to maintain?
Orange trees are popular and easy fruit trees to grow and care for when they are provided with the right conditions. You will need to closely monitor developing pest and disease conditions, however.
How many times a year do oranges bloom?
Orange trees bloom once a year in the spring.
Planting Bare-Root Fruit Trees. University of California Master Gardener Program of Sonoma County.