You may have already seen or eaten those mini oranges that taste super sweet and have the thinnest peel. But have you ever wondered what they are? These citrus fruits are called clementines and can easily be grown in your own garden. Clementine trees are ideal for beginner gardeners who want to grow citrus trees as houseplants. This is because clementines are hardier than their relatives and caring for them isn’t as difficult as you may think.
In this post, we’ll delve into all the important care requirements for a clementine tree so you can grow these citrus fruits in your own garden.
Clementine Tree Quick Overview
|Hardiness zone||8 to 11|
|Fertilizer||every other month|
|Max growth||6 feet|
|Water||once a week, more often for young trees|
|Climate||Mediterranean or tropical|
|Soil||sandy and fertile|
|Pests||fruit flies, soft scale, citrus canker|
Quick Facts about Clementine Tree
- Clementine trees are the hybrids of sweet orange and mandarin trees. Although they are closely related to mandarins and tangerines, clementines taste sweeter and are seedless.
- Clementines are also known as Christmas Oranges because their ripening season is from November to February.
- The skin of clementines is very easy to peel. The size of this citrus fruit is 4-6cm and the color is light orange. The rind of these tiny oranges is edible and fragrant. It is often added to cake toppings.
- The trees of clementine are just as attractive as the fruit itself, with slender green leaves that stand out against the orange fruit.
- In the spring, the white, fragrant blossoms of the tree transform into baby clementines (around 3 inches in size). However, the fruit won’t fully ripen until 7-10 months later.
Clementine Tree Care Guide
Light and Temperature
Clementine trees require full sun to grow the best fruit. If growing indoors, place the pot in the brightest location or supplement the tree with a grow light. Clementine trees can tolerate partial shade, but they won’t produce fruit without full sun.
This citrus tree can handle temperatures as low as 20 degrees fahrenheit. Having said that, long exposure to frost can cause damage to the tree’s roots as these trees are accustomed to Mediterranean climate.
Temperatures above 50 degrees F are ideal for producing the best clementines. In extreme heat conditions, protect the tree from sunburn by misting it regularly.
Watering and Humidity
Keep the soil consistently moist but not waterlogged. To do this, water the top inch of the soil and wait until it dries out before watering again. As a rule of thumb, water the tree once a week. If you have just planted the clementine tree outdoors or in a pot, water it up to 3 times a year during its first year.
Clementine trees don’t tolerate soggy soil so keep an eye out on the pot’s drainage and empty the excess water from the container’s tray often.
Clementine trees are grown in Mediterranean and tropical climates so they can tolerate high humidity. If growing indoors, keep them away from radiators and other heating sources as they can dry out the plant. Use a humidifier or fill the tray with pebbles and water to create humidity around the citrus plant.
When grown outdoors, your clementine tree needs slightly acidic, sandy soil to thrive. The soil must be well-draining without any puddling. And if the soil needs improvement, mix in some perlite.
The best way to determine the soil’s nutrient deficiencies is by using a home-testing kit. This way, you’ll find out whether the soil’s acidity is balanced or not. Commercial soil acidifiers will bring your soil’s pH levels back to normal.
While neutral soils are also suitable for growing clementine trees, the fruit will often taste sweeter than if it were grown in a slightly acidic soil.
If grown indoors, use a specially formulated citrus soil that’s well-draining and loamy.
Feed your clementine tree every other month throughout the year. These citrus trees don’t go dormant during the cold season so you will need to fertilize them at least 3 times in spring and again in fall. Apply a slow-release fertilizer that’s specifically designed for citrus fruits.
You may be wondering how to grow a clementine plant from seed if the fruit is seedless? The good news is, clementines can be propagated by grafting. The process involves taking an existing tree’s bud and grafting it onto a rootstock.
Follow these steps to successfully propagate a clementine tree:
Step 1. Begin by using a sterilized shear to cut through the rootstock’s bark in the shape of an upside down T. Take care so as not to cut in a crooked angle. It should be in a straight part of the trunk, around 4-6 inches from the base. Next, make an additional cut in a vertical shape and a horizontal cut about 1 inch in length. The idea is to cut through the tree’s bark without going further into the wood’s surface.
Step 2. Now cut a green stem from the tree you want to propagate measuring about 1 diameter.
Step 3. Slice the bud from the clementine stem using a sterilized budding knife. Make sure the cut is straight and from the back of the bark. The knife’s blade should be placed flat against the stem so you can take a thin slice of the bark from the above and below the bud.
Step 4. Now slice up the bud in a T shape cut. Place the tip of the bud in the up position just like it was on the original tree. The sliced bud should rest inside the bark on the rootstock with its tip pointing out.
Step 5. Wrap the grafted area with budding tape starting from below the incision. Continue wrapping the area around the trunk to cover the entire incision. This helps keep the bud firmly in place.
Step 6. After two weeks, remove the budding tape. If the bud is still green, your graft has been successful.
Step 7. To encourage the bud to grow, bend the top of the rootstock and tie it to the base of its trunk. If it doesn’t bend, cut halfway through the stem several inches above the graft. The new bud will be stimulated to grow on the rootstock while further buds will also begin to sprout.
Step 8. When planting your propagated rootstock in the ground or in a pot, insert a wooden stick loosely in the soil adjacent to the trunk and tie the bud to the stick as it grows. The wooden stick should be about 2 feet taller above the soil.
Step 9. After the new, grafted trunk has grown to the same height as the wooden stick, cut the rootstock’s trunk just above the grafted bud to ensure optimal growth. Within 2-3 years, your propagated plant will mature into a full-size clementine tree that produces fruit.
By following the above propagation tips, and with some patience, you will soon reap into the rewards of your hard work with tasty, sweet clementines!
Planting in the Ground
Dig a hole in the sunniest part of your garden. Make sure the depth is 20-40% more than the current root ball of your tree. Add some organic matter in the hole, including dried leaves and hummus before mixing it with garden soil. Loosely place the tree inside the hole and cover it with more soil. Add a layer of mulch around the tree to keep the soil moist and make sure you water it deeply for the next two weeks.
Tip: if the newly planted clementine tree isn't very stable, it may eventually fall. Add support using a stick or bamboo so that the tree can grow upwards.
Pruning a citrus tree is just as important as a regular haircut in order to keep it healthy and in shape. You can prune your tree any time of the year, but it is generally recommended to trim the overgrown branches during the end of winter or early spring.
You will need a clean shear to prune your tree. Look for overgrown branches that are obstructing walkways, dying twigs or any crossing ones in the center of the tree.
When pruning, don’t cut any more than one third of the plant at any one time. Additionally, don’t remove any flowering or fruiting branches. Otherwise your tree won’t produce fruit the following year.
Clementine trees produce white blossoms in the spring before their fruit starts growing. The clementines will ripen towards mid-November when the skin turns orange. If you notice the skin or the stem is still green, wait a little longer before harvesting.
Yellow leaves: this is a common yet solvable problem that is usually caused by lack of sunlight. To solve, move the tree’s location and thin out the yellowing leaves so the sun can reach the canopy.
Cold temperatures: when clementine trees are exposed to cold temperatures for long periods, they may not produce fruit. This can be prevented by moving them indoors and placing the potted plant in a sunny location.
Leaf drop: overwatering can lead to leaf drop. Check the soil to see if it’s draining water adequately and reduce your watering schedule to once per week only.
Pests and Diseases
Fruit flies: these are the most common pests you’re likely to encounter on your clementines. Fruit flies don’t just sit on the fruit; they will also lay eggs and carry bacteria. The best way to prevent fruit flies from sitting on your tree is by removing the fallen fruit from the ground and keeping the tree’s surroundings free of debris. Make sure you harvest the fruit on time to prevent these pests from attacking the tree. For severe infestation, use horticultural oil to keep them at bay. Sticky traps will also work effectively. Place the traps on the tree’s longest branches.
Soft scale: these pests feed on the tree’s sap and cause considerable damage over time. Soft scale leaves a sticky substance on the branches of the citrus tree that invites ants and sooty mold. As a result, the leaves will wilt or drop. To treat, apply neem oil or insecticidal soap to the affected areas of the tree. If treated early on, you can control this pest problem much easier.
Citrus canker: clusters of raised, brown lesions on the leaves, twigs or even on the fruit itself are signs of citrus canker. This pest problem can be prevented by keeping the tree dry and clean. Copper fungicide should be applied to control the existing outbreak.
Greasy spot: this is a fungal disease that plagues most citrus trees. The obvious signs of greasy spots include brownish-yellow blisters on the leaves, often underneath away from sight. As the disease progresses, the blisters turn oily, hence the name. This disease can cause significant damage to the tree, particularly in winter. It can infest the fruit and cause leaf loss. To treat and control greasy spots, remove any fallen leaves and spray the tree with a liquid copper fungicide in summer. A second spray application will be necessary in early fall to protect the tree’s growth.
Root rot: also referred to as brown rot, this common citrus tree disease is caused by a specific fungus from the phyto-phthora species. The symptoms are brownish patches on the tree’s bark or trunk. You will commonly see dark brown sap oozing from the infected area. If left neglected, the root rot disease can advance through the trunk and kill the tree. This disease can also cause the fruit to decay and the foliage to turn yellow. To prevent the fungus from attacking the fruit, make sure the soil is well-draining and prevent puddling.
Did you find our clementine tree care tips useful? If so, share the article now and let us know how you progress with your citrus plant by leaving your comments below!