Citrus, oranges, lemon trees… all there is to know

Citrus are magnificent fruit trees native to Asia and introduced to Europe by the Arabic civilization. From there, they spread to America.

Like the orange tree, lemon tree and kumquat, most of the time citrus have evergreen leafage and only grow directly in the ground in regions where the winter climate is mild.

Grown for example in the Mediterranean area, they are more and more commonly found on our terraces, decks and patios, which makes them very trendy nowadays.

In cooler regions, they’re grown in pots, so that they can be brought out of the freezing cold over winter.

Main citrus to grow at home

There is of course the lemon tree, the orange tree, the clementine and the pomelo tree which produces grapefruit.

Additionally, you can find kumquat, also called Fortunella margarita, which produces cute tiny fruits to savor.

Lastly, the only citrus suitable for indoor growing inside a heated house or apartment in winter is the calamondin.

Which climate is best for growing citrus?

Areas that border the sea in Mediterranean type climates like the American South-East and South-West coasts are very well suited for cultivating citrus plants.
There, they can be planted outdoors without much risk.

Full sun exposure is important for best fruit-bearing.

Further North, if you inhabit a region where it doesn’t freeze, you can plant them in the ground on the condition that they be well protected from wind and in a space well endowed with sunlight.

If it does freezes in your area, favor potted growing or growing in garden boxes and bring your citrus inside an unheated lean-in for instance, which will be quite cool in winter but won’t freeze and endanger them.

Growing potted citrus as indoor plants

The variety best suited to growing indoors is calamondin, which is an indoor orange tree that can stay in the same room year-round.

Potted growing as an indoor plant for the other citrus plants isn’t problematic either, except that they must spend winter in a cooler room.

• During repotting, feel free to add about an inch (3 cm) of clay pebbles or gravel at the bottom of the pots in order to increase drainage.
  This helps avoid having the roots stagnate in dampness.
• Set your citrus plant as far as possible from any radiator or heat source. This would tend to dry it off.
• Position your citrus with as much light as you can, but again avoid direct sunlight which would tend to dry the plant off.
• Bring the pots out after the last frost spells, during the month of May most often.

Planting citrus in pots

Refer to our guidance on how to best care for your potted citrus lemon tree and orange tree. In fact, for other citrus plants, the guidelines are almost exactly the same.

• Potted orange tree, everything you need to know
• Potted lemon tree, all the growing tips

Watering citrus

• Avoid saucers or garden boxes with water reserves, again to avoid having roots wallow in water, and remember to add a bed of clay pebbles or gravel as mentioned above.
• Water regularly as soon as the soil is dry, but not too much. It is often said that watering every two days in summer and once a week in winter is fine.
• As for fertilizer, you can add special citrus-specific organic fertilizer once or twice a month.

Fruits and fruit formation period for citrus

Citrus bear fruits from November to May, except for lemon trees which can bear fruit all year round.

Indoors, fruit formation is much more difficult. As your experience grows in caring for your citrus, you’ll end up getting better at obtaining fruits from your plants.

What is the best way to propagate citrus?

You can prepare cuttings and layering (August is best for this).

When to prune citrus

More or less every 2 years, in the month of March.
Prune lightly to renew the vigor of your citrus plants.

• Clear the center to let light seep through to the whole plant.
• Reduce the length of branches by 1 or 2 buds.

As an example, look at what it takes to prune finger lime, a particularly thorny variety.

Diseases and parasites that often attack citrus

• Scale insects – techniques and organic treatments to avoid them (more general information on scale)
• Rust – a common citrus disease
• Thrips – responsible for silvery streaks on fruits
• Gall wasp – triggers swelling on branches and disrupts growth

Read also:

• Growing orange trees
• Mandarin tree care
• Growing kumquat