How to Grow an Indoor Orange Tree

An indoor orange tree is a great way to add greenery and fragrance to your home. As well as helping to improve air quality houseplants are also good for our mental health. Even the smallest houseplant can help to reduce your stress levels and improve your state of mind.

An indoor orange tree is a great way to introduce some life and color to your home during the darkest, winter months. They are also pleasingly easy to care for.

1 Easy to care for
Easy to care for, an indoor orange tree will fill your home with color and fragrance throughout the winter months. 

If you are new to caring for plants there are few easier places to start than with an indoor orange tree. For gardeners in cool or cold climates, an indoor orange tree, is also the easiest way to grow your own oranges. Growing plants undercover means that USDA zones do not apply. This guide will show you everything that you need to know.

Selecting a Suitable Variety

Gardeners have been growing indoor orange and citrus plants since the 17th century. Then estates would construct greenhouses or conservatories specifically for the purpose. Luckily, today, we don’t need to do anything that extreme. There are a number of different varieties of orange tree that are suitable for indoor cultivation.

Calamondin Orange is one of the most popular indoor varieties. Easy to cultivate it is a great place to start. However, its fruit is small and sour, meaning that it is best grown as an ornamental plant.

If you want an indoor orange tree that produces edible fruit, Tahitian Orange is a popular, reliable variety. A thornless plant it produces small, sweet fruit that is a combination of tangerine and lemon.

2 The reliable and easy to care for Calamondin
The reliable and easy to care for Calamondin is one of the most popular varieties of indoor orange tree. 

Satsuma is another reliable, easy to care for option. While technically a tangerine not an orange, this variety is popular for its clusters of fragrant flowers.

How to Grow an Indoor Orange Tree

Indoor cultivation is largely the same as any other form of container gardening. Soon after you purchase your chosen plant you should transplant it into a slightly larger container. Store purchased plants can be allowed to stay in containers that are only just big enough to hold them for far too long. Transplanting soon after purchasing ensures that the plant’s root system doesn’t become deformed or pot bound.

The most obvious sign that a plant is becoming pot bound, and in need of re-potting, is that the soil dries out more quickly between waterings. Another clear indication that your plant is pot bound is that its roots will emerge from the drainage holes in the bottom of the container. The foliage of a pot bound plant can also look unhealthy.

As well as soon after purchasing, you will also need to repot your plant every two or three years.

The best time to plant or re-pot your orange tree is in the spring, just as new growth begins to emerge.

What Container Should I Use?

The indoor orange tree does best in containers that encourage drainage. A terracotta pot is more porous than plastic containers. Not only does a porous container promote drainage it also helps to keep the roots and soil well aerated. However, you will need to water the plants in terracotta containers more often than plants growing in plastic containers.

If you don’t have a terracotta container, don’t worry. Indoor orange trees will be just as happy growing in a plastic container. Many growers prefer plastic containers because they are easier to move and are better at retaining some moisture.

Ultimately it makes little difference what material your chosen container is made from. Just make sure that it is clean and has drainage holes in the bottom.

When you re-pot a plant, the new container should be no more than 2 inches wider and deeper than the old container. Gradually moving plants into slightly larger containers each time is preferred over potting straight into a large pot. Placing plants in containers that are far too large for their current size can cause shock and stunt growth.

When it comes to growing an indoor orange tree a deep container is useful. As the plants grow and flower they can become top heavy. A top heavy plant in a shallow container is in danger of over balancing and toppling. This can damage not only the fruit and flowers but also the tree itself.

3 Terracotta containers help to keep plants in aerated well draining soil

Terracotta containers help to keep plants in aerated, well draining soil. However they can be more difficult to move than plastic containers. 

What Sort of Soil Should I Plant in?

The soil should be lightweight and well-draining. A general purpose soil mix is fine, just avoid mixes that are too heavy or designed to retain moisture. While cacti soil mixes are well draining, they may be too loose for an indoor orange tree.

Working vermiculite or perlite into a fresh soil mix will further help to improve drainage. Alternatively work in wood chips, pebbles or coarse sand. All of these improve drainage and aeration.

How to Plant an Indoor Orange Tree

Before planting allow the plant to dry out so that the soil is no more than slightly wet. This may take a few days if you have recently watered the plant.

Use a blunt knife to loosen the soil around the edges of the container. Loosening the soil helps you to easily remove the plant without causing it any unnecessary damage or stress. To pull the plant from its container, hold the main stem and gently lift it up.

Fill the new container about a quarter full with your fresh potting mix. Place the orange tree in the center of the new container. Add more fresh potting mix in around the plant, filling the container. Firm down the potting mix.

Once the tree is planted, water well. For the next few weeks, as the plant establishes itself you will need to water the plant regularly to prevent the soil from drying out. During this period you will also need to closely monitor the health of the plant. Indoor orange trees can be particularly fragile in the period shortly after repotting.

How to Care for an Orange Tree Indoors

Once planted indoor orange tree care is relatively straightforward. The main requirement is light. While you don’t need a conservatory or greenhouse you will need to place the plant near a window that gets enough daylight.

The indoor orange tree likes lots of bright, indirect sunlight, preferably 6 to 8 hours every day. Place the plant near a window that gets lots of indirect light. This ensures that the plant receives lots of light. Usually this position will be either a south or west facing window. During the summer months you may need to move the plant further away from the window to prevent it from becoming sunburnt by the intense summer heat.

If you are unable to provide enough natural light, boost the plant’s light levels with a grow lamp. Artificial light can be just as beneficial as natural light.

In the summer months when temperatures are no more than 86 ℉. you can take your plant outside. Place it in a sunny, sheltered area of your garden or balcony. The plants thrive when allowed to enjoy some direct sunlight and fresh air. Remember to bring the tree back inside when temperatures threaten to fall. This should be long before temperatures reach a low of 46 ℉.

4 Grow lights are a great solution if you cant provide enough natural light

Grow lights are a great solution if you can’t provide enough natural light. Both young plants and more established trees will benefit from exposure to artificial light sources. 

Temperature and Humidity

The indoor orange tree does best if the daytime temperature averages around 68 ℉. Keep the temperature as consistent as possible. These plants struggle in drafty positions.

At night the temperature should be no lower than 58℉. A gap of 5 to 10 degrees between daytime and nighttime temperatures is recommended. Without this change in temperature the indoor orange tree will struggle, or fail, to flower.

Ideally humidity levels will be between 50% and 70%. This humidity range is similar to the natural, tropical environment of the indoor orange tree.

A humidifier is an easy way to replicate these conditions. You can also place the plant pot on a humidity tray or, simply, a tray filled with water and pebbles. The water level should be just below the top of the pebbles and the container should sit on the pebbles, not contacting the water. As the water evaporates you will need to regularly re-fill the tray to maintain humidity levels.

Avoid placing the plant near air vents or sources of artificial heat. Particularly in the winter months the air in these areas can be particularly dry. This not only lowers humidity levels but can cause the soil and plant’s root system to quickly dry out.

If you are having difficulty maintaining humidity levels use a digital thermometer or hygrometer to accurately monitor temperature and humidity levels.

Water

The indoor orange tree can have specific watering needs. How often you water will depend on the size of the plant, the soil it is sitting in and the time of year.

Regularly checking the soil will tell you when the plant requires water. The easiest way to check moisture levels is to stick your finger in the soil. If the top inch feels dry it is time to water the plant. For a more accurate measure try using a soil moisture meter such as the Ruolan Soil pH Meter.

Never allow the soil to dry out. Once the roots of the indoor orange tree become dry they will begin to die.

5 Mulching around your plant will help to keep the soil moist for longer

Mulching around your plant will help to keep the soil moist for longer. An organic mulch will slowly break down over time, giving your plants an extra nutritional boost. 

When you water the plant make sure that you thoroughly soak the soil. Continue watering until water begins to flow through the drainage holes in the bottom of the container. After watering ensure that all the water has drained away. Never allow the plants to sit in water or waterlogged soil. This can cause root rot, which in severe cases can kill plants.

Don’t be surprised if you need to water more often during the warmer spring and summer months. The warm weather encourages plants to grow, meaning that they will use more water. Usually you will need to water once or twice a week during these months.

During the winter, when the plant is dormant, you can reduce watering to once a week or once every two weeks. Again, check the soil to accurately gauge when to water your plant.

Harvesting your own rainwater to re-use on plants is a great way to cut your water usage. It is also easy and good for the environment. Whether you are harvesting rainwater or using water from the tap always allow the water to warm up to room temperature before applying. Cold, or hot, water can shock plants, causing them to wilt or drop their leaves.  

Fertilizing

A tropical plant, the indoor orange tree needs lots of nutrients to thrive and flower. During the growing season apply a citrus fertilizer once a week. Liquid plant feeds are easily incorporated into your watering routine.

Growth will slow during the fall and winter months. However, the plants will still require fertilizing. From October to March apply a winter citrus plant fertilizer once every two weeks.

A citrus plant feed is recommended because it contains extra micronutrients such as manganese, iron, zinc and magnesium as well as nitrogen. These ingredients help citrus plants to thrive. The fertilizer should also include phosphorus and potassium. If you don’t want to purchase a commercial plant feed, there are plenty of reliable recipes allowing you to make your own plant feed at home.

Pruning

The indoor orange tree is a slow growing plant. As a result it is pleasingly low maintenance, requiring little regular pruning.

During the spring and summer months, when the plant is actively growing, pinch out any fresh growth on stems that are beginning to get too long. Pinching out stunts the growth of the stems and encourages side shoots to emerge. As well as preventing the plant from becoming too leggy, pinching out also helps to create a bushier plant.

New growth can also be pruned away when it reaches 6 inches in length. Be careful not to prune away too much new growth. Pruning too much can deter the plant from producing further new growth.

6 Always use sharp tools when pruning

Always use sharp tools when pruning. This helps you to make precise cuts without damaging the plant. Cleaning your tools after pruning reduces the risk of transferring disease between plants. 

During the fall and winter months prune away any branches and shoots that appear diseased or broken. Just before the plant begins to grow again clear up dense patches by pruning away some of the stems. This is best done in February or early March. Dense and entangled branches may look interesting but they can prevent air from circulating around the plant. This can lead to the plant becoming diseased.

Common Pests and Problems

If your plant is in a favorable position and well cared for you are unlikely to encounter any major issues.

During the winter months not only are temperatures below the ideal for an indoor orange tree but there is also less daylight than at other times of year. This can cause some plants to drop their leaves.

One or two dropped leaves is natural and nothing to worry about. However, if the plant continues to drop leaves you may need to make some changes. Grow lights will provide the plant with more light. Relocating the indoor orange tree to a warmer room will also help.

If you do need to relocate your indoor orange tree don’t place it near any artificial sources of heat. These areas are notorious for creating dry air and lowering humidity levels. These are the conditions that the indoor orange tree dislikes the most.

Yellowing foliage is often a sign of a nutrient deficiency. Applications of citrus fertilizer will correct this. If you are already feeding the plant, check your watering routine. Yellowing leaves can also be a sign of overwatering.

How to Deal With Infestations

Pests such as aphids, whitefly and fruit fly can target the plant, particularly if it is placed outside during the summer. An application of soapy water or insecticidal soap, easily made at home, will cure most infestations.

Spider mite infestations can be controlled by wiping the leaves with a damp cloth. This deters the pests from settling on the plant. Wiping the foliage is best done in the morning. This gives the foliage time to dry before the cool evening temperatures arrive.

Scale is an insect that feeds on the sap of the indoor orange tree. These pests can often be found on the plant’s stem or on the underside of the foliage. Scale can be difficult to get rid of.

Adult scale bugs are best removed by wiping alcohol on a swab on the insect. If you need to apply alcohol try to get as little as possible on the foliage of the plant. Newly hatched scale pests can be removed by an application of insecticidal soap. Scale can be difficult to get rid of. Solutions may need to be repeated a couple of times before the plant is fully clear.

Flowering and Pollination

Indoor orange trees tend to flower during the winter months, brightening up dark days and filling your house with a fragrant aroma. Many people are content to just enjoy the flowers of their indoor orange tree. Others decide to go one step further and help the tree to produce fruit.

If you want the flowers to turn into fruit you will need to pollinate the plant yourself.  Ensure that nighttime temperatures are 5 to 10 ℉ lower than daytime temperatures. Remember also that younger plants, under two years, produce fewer flowers than more mature plants.

7 Outside visiting pollinators such as bees will help your plant to produce fruit
Outside visiting pollinators such as bees will help your plant to produce fruit. If you are cultivating indoors your plant will require some help from you. 

A pollination tool helps you to easily move pollen between flowers, replicating the actions of bees and other pollinators. Kits such as this Indoor Garden Kit are easy to use and readily available. Alternatively you can use a small, soft paintbrush or a cotton swab.

To transfer the pollen inspect the flowers on the plant. You should see small collections of pollen, a powdery grain, on the ends of the stamen (stalks) that encircle the pistil (the large stalk in the center of the stamen ring). Brush your chosen implement along the flower’s stamen, if you look carefully you will see the pollen moving onto your brush.

Brush the pollen covered tool onto the stamen of another flower. This transfers the pollen from one flower to another. Repeat this process with each flower on the tree. To maximize your potential yield you will need to repeat this process once a week.

You won’t know if your attempts at pollination have been successful until the flowers begin to fade. Pollinated flowers will give way to small fruit. Continue to water and fertilize your indoor orange tree as the fruit grows. When the oranges are large and ripe they can be harvested simply by picking them off the plant.

8 Fragrant and colorful an orange tree is a great addition to any home

Fragrant and colorful, an orange tree is a great addition to any home. It is also pleasingly easy to care for. 

An indoor orange tree is a great way to add color to your home during the winter months. The plants delicate flowers and fragrant aroma will fill your home and improve your state of mind. An easy to care for plant, this is a great choice if you are new to container gardening. With a little consideration and attention an indoor orange tree is a welcome addition to any home.

How to Grow an Indoor Orange Tree cover image