How to grow an orange tree in the ground or in a pot?

Which variety of orange tree to choose?

There are three types of oranges, each suited for a specific use:

• Navel oranges with large, seedless, juicy, and fragrant fruits. The variety ‘Washington’ is certainly the most well-known.
• Juice oranges.
• Blood oranges with a more or less pronounced red core depending on the cultivar.

If the orange tree is appreciated for its glossy foliage and highly fragrant flowering, there are also ornamental orange trees. For instance, the ‘Corrugata’ orange tree, a fruit of hybridization between sweet orange and bitter orange, is decorative with its undulating-skinned oranges.

The amazing ‘Corrugata’ orange tree

Commercial orange trees are most often grafted onto rootstocks such as the bitter orange (Citrus aurantium) or the trifoliate orange (Poncirus trifoliata). These rootstocks provide it with superior hardiness, better disease resistance, and adaptability to different types of soil.

Planting Orange Trees in the Ground: Where, When, and How?

Very little hardy, the orange tree is relatively resistant down to -5 to -7 °C. This is why it is grown in open ground across a wide area of the Mediterranean coast with mild and gentle winters, but it adapts perfectly well to container cultivation.

Where to plant?

It is essential to choose a sunny location, without being scorching, sheltered from the wind and cold drafts. As it does not tolerate sea spray, seaside gardens are not suitable for it.

It will also thrive in a light, well-drained and cool soil, rich in humus. It particularly fears clayey or poorly drained soils that retain moisture in winter. Likewise, it is wary of soils that are too calcareous or too acidic.

In open ground, the orange tree accommodates a good garden soil, enriched with compost, to which sand or pumice will be added to ensure drainage.

The orange tree loves rich, well-drained and cool soils

When to plant?

Planting in spring, between April and May, is preferred. Avoid any period of frost or drought.

How to plant?

• Dig a hole two to three times wider than the root ball.
• Ensure good drainage by adding gravel or clay balls to the bottom of the hole.
• Soak the root ball in a bucket of water to rehydrate it.
• Amend with compost or well-rotted manure, mixed with the extracted soil.
• Place the root ball level with the soil, without burying the graft point.
• Backfill, lightly compact to avoid air pockets, then water generously to ensure root contact.
• Mulch with organic mulch.

Pot planting: where, when, and how?

In regions where winters are colder, the orange tree is planted in a pot or container. It can thus find its place on a balcony or terrace, in a courtyard or patio, sunny in the morning and partially shaded during the hottest hours. Windy locations should be avoided. In winter, it will move to a conservatory, a cold greenhouse, or a winter garden.

What pot and substrate to choose?

A pot with drainage holes should be chosen, neither too large nor too small, just slightly larger than the root ball. To facilitate drainage, a layer of clay balls or coarse gravel should be placed at the bottom of the pot.

The substrate will consist of 1/3 garden soil, 1/3 special citrus substrate, 1/3 coarse sand, to which well-decomposed compost is added.

When to plant in a pot?

Ideally, planting should be done from March to May to avoid frost, as the orange tree can be placed directly outside.

Growing an orange tree in a pot is demanding, but largely possible

How to plant or repot an orange tree?

• Once you have chosen your pot with drainage, place your drainage layer (coarse gravel, clay balls).
• Soak the root ball in a bucket to rehydrate it.
• Fill half of the pot with your substrate.
• Gently untangle the roots of the root ball.
• Position the root ball about 2 cm from the edge, ensuring not to bury the grafting point.
• Fill the pot with the remaining substrate and gently compact it.
• Water abundantly to thoroughly moisten the root ball.
• Apply organic mulch at the base of your orange tree.

What care does an orange tree need?

Comme le citronnier et le pamplemoussier, l’oranger est un citrus trees that are thirsty for water and fertiliser. C’est pourquoi il doit bénéficier d’un entretien suivi pour espérer obtenir une fructification correcte.

Watering the orange tree

En pleine terre, un oranger doit être arrosé régulièrement au printemps et en été, mais sans excès. Il faut toujours laisser la surface sécher un peu entre deux arrosages. En hiver, les intempéries devraient lui suffire.

When grown in a pot, an orange tree is more demanding. Entre mars et octobre, waterings occur 3 to 7 times a week depending on the heat. En plein été, un arrosage quotidien est recommandé, surtout par fortes chaleurs. En hiver, un arrosage une fois par semaine suffit amplement. Il faut toujours laisser s’écouler l’eau et vider la soucoupe ou le cache-pot. 

Les arrosages se font à l’eau non calcaire à température ambiante. L’eau de pluie est la meilleure.

Fertilising the orange tree

Pour les orangers cultivés en pleine terre, un apport de compost peut être fait au printemps et en automne.

En pot, la fertilisation est essentielle, car le substrat s’épuise vite. From March to October, a liquid fertiliser specially for citrus trees should be applied every three weeks or a slow-release fertiliser specially for citrus trees every six months.

Pruning the orange tree

Au printemps, you can carry out light pruning with scissors or pruning shears on the new shoots to maintain its lovely rounded habit and stimulate flowering and fruit production. Profitez-en pour éliminer le bois mort, les branches mal placées ou abîmées, et les gourmands.

Repotting the orange tree

This repotting is done every 2 to 3 years or so, between April and June, or at the end of summer for older trees. Lorsque l’oranger ne peut plus être rempoté à cause de sa taille, un surfaçage suffit. Il faut remplacer les 10 cm de substrat supérieurs.

Winter protection

En pleine terre, les orangers se montrent tolérants jusqu’à – 7 °C sur de courtes périodes. Mais ils restent très sensibles aux gelées. C’est pourquoi, dans les zones en limite de rusticité, it is preferable to install a winter cover and mulch the base with a good layer of dead leaves.

Les sujets en pot doivent être hivernés dans un local lumineux non chauffé (5 à 10 °C) comme une véranda, un jardin d’hiver ou une serre.

Managing diseases and pests

Scale insects and aphids are relatively common on orange trees, whether in the ground or in pots. A solution of black soap (5 tablespoons in a litre of water) is an effective and natural treatment. Repeat weekly if necessary. Red spider mites can also settle on the foliage of the orange tree. Mist or giving the foliage a shower can reduce their presence.

On the disease front, sooty mould can develop due to the presence of scale insects or aphids. It is essential to treat these pests to prevent the appearance of this black powder that blocks photosynthesis. Other fungal diseases may occur, often when cultural conditions are not optimal.

To learn more: Orange tree: how to identify and treat its diseases and pests?