The reason orange tree lose their leaves is usually because of low temperatures, drought or a lack of soil fertility. Orange trees are need mild temperatures in Winter and lose their leaves in temperatures lower then 50°F (10°C). Dry soil causes the leaves curl up turn yellow and fall off.
Orange trees often lose their leaves when brought indoors for Winter due to the sudden contrast in humidity, temperature, and sunlight.
If your orange tree is losing leaves in Summer, this is most often due to underwatering, overwatering or a lack of nutrients in the soil.
Keep in mind that whilst orange trees are not deciduous, they often drop some leaves in Winter, even when grown in the perfect conditions.
To save your orange tree that is losing leaves, it is important to replicate the conditions of its preferred Mediterranean environment with full sun, mild temperature, moderate humidity and moist, yet well draining soil. The leaves can often regrow once the conditions are more favorable.
Keep reading to learn why your orange tree is losing leaves and how to implement the solutions to save it…
Orange Trees Drop Their Leaves When Temperatures are Below 50°F (10°C)
Orange trees are native to subtropical climates and have been cultivated to thrive in Mediterranean environments where they are grown outdoors all year due to the mild Winters.
Orange trees are not cold or frost hardy and should be planted in pots and moved indoors when the temperature at night is forecast to be under 50°F (10°C) or lower, otherwise the orange tree is likely to lose its leaves or even die back due to frost.
Citrus trees of all types do become hardier and more resilient to cool temperature as they mature (particularly those with wider trunks), whereas smaller, less mature orange trees can be much more vulnerable to leaf drop from cold temperatures.
There are some varieties of orange trees are cultivated to resistant cold temperatures, but all cultivars require protection from frost over Winter, so it is important to bring them indoor and place them in either a:
- Heated greenhouse
- Sunny South facing window (ideally 6 hours of direct sunlight)
- A porch or conservatory.
Ideally choose a location that has the most sun so that the orange tree can still benefit from as much natural light as possible during Winter.
If the orange tree is losing leaves in Fall/Winter yet the temperature is still above 50°F (10°C) this is usually because of a reaction due to a sudden temperature fluctuation as the nights get cooler and there are fewer hours of sunlight.
The solution is to still bring the tree indoors (or use horticultural fleece if planted outdoors) and ideally find a nice sunny spot.
Typically orange trees that have lost some of their leaves can recover and regrow leaves in the Spring with warmer temperatures and more sunlight.
However, it should be noted that bringing orange trees indoors can also trigger more leaves to drop due to a sudden change in conditions or if you are not following the best practices of care…
Indoor Orange Tree Losing its Leaves
If you have moved your orange tree indoors (or in a greenhouse) for Winter or recently bought one from a garden center, the orange tree often loses some, if not all of its leaves due to the contrast in conditions from outdoors to an indoor environment.
Orange trees are carefully cultivated in commercial greenhouses before sale, which means they have acclimated to growing in very specific, optimal conditions and experience significant transplant stress if they are moved to a different environment.
All citrus plants are sensitive to a sudden variation in their environment and can lose their leaves because:
- Humidity. Houses in Winter have much lower humidity due to indoor heating which dries out the air and saps moisture from the orange tree’s leaves, which causes them to drop off. Orange trees grow best in 30% to 60% humidity.
- Temperature. A sudden difference in temperature can cause enough shock for the orange tree to drop its leaves. It is also worth noting that indoors the temperature is often increased at night due to indoor heating which is the opposite cycle of temperatures that orange trees experience outdoors with cooler evenings and warmer days, which can contribute to the leaves dropping.
- Sunlight. Orange trees prefer full sun and can lose their leaves indoors with less light.
- Air currents from forced air or air conditioning can also dry out the air to the extent that the orange tree drops its leaves to conserve moisture.
- Difference in watering. Orange trees also typically need to be watered less often in Winter as they go dormant. However due to increased heat and dryer air, the soil can dry out and bake hard and cause water to run off the surface and down the side of the pot, without infiltrating the soil properly and reaching the roots where it is required, causing leaf drop due to drought stress.
It is very common for an orange tree to drop its leaves when brought indoors, but this does not necessarily mean the tree is going to die, as it is usually just a reaction to the stress of being moved. There are several ways to mitigate the impact of of this stress to ensure the orange tree survives despite losing its leaves…
How to Revive an Indoor Orange Tree That is Losing Leaves
The way to revive an orange tree after the leaves have started dropping and to reduce any further leaf drop…
- In Winter, houses are particularly low in humidity compared to outdoors due to indoor heating, so to decrease the contrast in humidity, mist the orange tree every day to create a humid micro-climate. You can also buy a plant humidifier at garden centers and online which provide consistent humidity to prevent the orange tree’s losing too much moisture and dropping off.
- Place the orange tree in the sunniest, south facing window, porch or balcony of the house or in a heated greenhouse if possible. The sudden decrease in daylight indoors is one of the main contributors of leaf drop.
- It is important to maintain a consistent room temperature to prevent the orange tree from losing its leaves. Keep the tree away on the other side of the room form any source of indoor heat such as radiators, fires and out of the way of any air currents from forced air. Typically orange trees can grow well with indoor temperatures as long as they are not next to the source of heat and the room does not cooler then 50°F (10°C) at night.
- The orange tree has to contend with a difference temperature, dry air currents and low humidity when indoors, which can all increase water loss from the leaves, causing them to drop. This means you may have to increase the frequency of watering of the orange tree to avoid losing leaves.
- However this can be a balancing act as orange trees grow at a much slower rate in in Winter due to less hours of sun and a lower light intensity which means they require less water. Too much moisture around the roots in Winter can result in root rot which also causes the leaves to turn yellow and drop off.
- The key is too water the soil with a good soak in Winter and then wait until the top 2 inches of the soil feel dry, before watering again. This cycle of watering prevents the orange tree from drying out completely and mitigates the risk of root rot.
Some leaf drop does naturally occur in Winter even on oranges trees that are grown commercially in the optimal conditions, so don’t worry.
Even if all the leaves drop in Winter, as long as your orange tree is being cared for properly and has not died back due to frost then then citrus trees are surprisingly resilient and the leaves can regrow in Spring.
As soon as the weather warms up and the night temperatures are consistently warmer then 50°F (10°C) place the potted orange tree outdoors or in a greenhouse so that they can benefit from more hours of sun which should stimulate new leaf growth.
Orange Trees Losing Their Leaves in Summer
Usually orange trees lose their leaves in Summer due to drought or a lack of nutrients in the soil. Orange trees need consistently moist soil in Spring and Summer during active growth and a citrus fertilizer. If the soil dries out of the soil is nutrient poor, the orange tree leaves droop and drop off.
Orange trees are particularly nutrient hungry in Spring and Summer, when the leaves are growing and fruit is forming. If the orange tree is planted on nutrients poor soil then the leaves tend to curl, turn yellow and drop off.
Orange trees that are planted in pots can exhaust the available nutrients in the pot after a year or two which again can result in falling leaves in Summer.
It is also worth noting that orange trees prefer to grow in full sun, so if any overhanging trees are casting shade on the orange tree, then this can be responsible for poor growth, lack of flowers or fruit as well as fewer leaves in summer.
Overwatering and Drought…
Orange trees require a balance of well draining soil that stays consistently moist during Spring and Summer.
Essentially what this means is that the orange tree does not like to have its roots in boggy saturated soil as this results in root rot and can cause the leaves to drop and die back.
Orange trees can suffer root rot because:
- They are planted in boggy low lying areas of the garden.
- Pots without drainage holes in the base.
- The use of saucers, trays or decorative outer pots that prevent water from draining properly and cause water to pool around the orange trees roots.
- Watering too often.
However if the orange tree is planted in sandy quick draining soil, then the soil may drain too quickly for the orange tree’s root s to draw up the moisture they require which results in curling leaves that drop off.
This problem can be more prevalent in Summer for orange trees planted in pots as pots can dry out too quickly with blazing sunshine and scorching temperatures.
Smaller pots have less capacity for soil and therefore hold less moisture, so even if you are watering regularly the soil can still dry out too quickly and the orange tree’s leaves fall off due to drought.
Too much wind can also dry out the leaves and cause them to drop off so plant the orange tree in a shelter spot in the garden or provide shelter with shrubbery as a wind break.
Revive Orange Trees Losing Leaves in Summer
- Use a citrus fertilizer in the Spring and Summer to prevent falling leaves. A specific citrus fertilizer provides all the nutrients the orange tree needs at the right concentration. This should provide enough nutrients to support the leaves and promote the development of oranges and growth of the orange tree.
- Check to see it your orange tree roots are pot bound. If the roots are pressed up against the sides of the pot it is time to repot the orange tree to another pot one size up. The larger pot provides more soil and greater capacity for retaining moisture which should help the tree retain its leaves. The best time to repot an orange tree is in the Spring but repot in the Summer if the leaves are falling drastically.
- Cut back any overhanging trees or shrubs that may be casting shade on the orange tree. Orange trees need full sun so move the orange tree is necessary to a nice sunny area of the garden, which can help stimulate the growth of new leaves.
- Orange trees need a balance of around 2/3’s compost and 1/3 grit to retain moisture and avoid root rot. This soil mix has the right amount of compost to retain moisture to avoid drought and is also porous and well draining due to the grit which prevents root rot. Mix the compost and the grit thoroughly before repotting your orange tree.
- Plant orange trees in pots with drainage holes in the base and use feet underneath the pots. Using bricks to elevate the orange tree’s pot off the ground helps promote good drainage. Pots that are placed directly onto patio slabs can sometimes prevent good drainage and the potting soil stays damp for too long.
- Water orange trees when the first inch of soil feel dry. There is no universal advice for how to often you water your orange tree as this can depend on the temperature, maturity of the tree, size of the pot etc. So the best way to do it is to feel the soil regularly with your finger to detect how long it takes for the top inch of the soil to feel somewhat dry, at which point give the orange tree a really good soak.
- Sometimes the soil can bake hard due to blazing sunshine and high temperatures. This can cause water to run off the surface of the soil and down the side of the pot without infiltrating the soil properly and reaching the roots and therefore result in falling leaves due to drought. If you scratch back the first layer of the soil, it can be very dry underneath despite watering. In which case, if you the orange tree is planted in a pot, if possible lift the pot into a wheel barrow (or large container of some kind) full of water and submerge the root ball for 10 minutes or so, which allows the water to properly soak into the soil to reach the roots and loosen the soil’s texture.
The best way to revive orange trees that is dropping leaves is to recreate the conditions of the oranges tree’s preferred habitat with full sun, well draining yet moist soil, use a citrus fertilizer and protect the tree from temperature cooler then 50°F (10°C).
The orange tree should regrow new leaves once the conditions are more favorable.
However the orange tree may not produce fruit this year if it has lost a lot of leaves and been under significant stress.
Orange trees that have lost their leaves due to waterlogged soil often do not recover because of root rot.
(If you think your orange tree is dying, read my article, how to revive a dying orange tree for the solution).
- Orange trees lose their leaves because of overwatering, underwatering, poor soil, too much wind or low temperatures. Orange trees do not tolerate temperatures lower then 50°F (10°C) and react to cold temperatures by dropping their leaves. Drought causes the leaves to curl up turn yellow and drop off.
- Indoor orange trees lose their leaves because of a sudden contrast in conditions due to indoor heating, lower humidity or a lack of sunlight. Orange trees need full sun, consistent temperatures and high humidity when indoors to retain their leaves.
- Orange trees lose their leaves in Summer because of drought, or overwatering and slow draining soils. Orange trees need a balance of moist soil that is able to drain effectively. If the soil is waterlogged or too dry the leaves turn yellow and drop off.
- To save a orange tree losing its leaves, recreate the preferred conditions of its Mediterranean with moist yet well draining soil, full sun, shelter it from excess wind, apply a citrus fertilizer and protect the tree from temperatures cooler then 50°F (10°C) and the leaves should regrow in the Spring.