Hardy citrus

USDA climate zones are defined by the minimum temperatures reached during the year (usually in January or February).

However, in a given region, minimum temperatures can vary significantly, sometimes over a few kilometres or even just a few hundred metres.

Factors that positively influence minimum temperatures include, for example:

• Site orientation

A southern exposure greatly reduces minima and their duration

• Wind protection

A sheltered area will gain warmth, and extreme cold will be shorter there

• Presence of a lake

A sufficiently large water body will buffer and shorten cold periods.

• Urban environment

In cities and suburbs, the urban heat island effect reduces nightly minima by several degrees in winter.

These factors can combine to create micro‑climates 8a/8b (-12.2 C à – 6.7 C) in the heart of a 7a/7b region (-17.8 C à -12.2 C).

To guarantee an optimal growth to a citrus tree it is necessary to install it in a place sheltered from the wind, well exposed to the sun especially in the morning.

You can plant near a house without fear, the main root of a citrus tree will plunge vertically into the ground. No risk for the foundations. The horizontal surface roots are not penetrating. The heat radiated by the walls will make you gain several degrees.

A dense hedge or a perimeter wall will also have a moderating effect on the extremes.

If you're planting in an orchard, don't space the trees too far apart.
Check the recommended planting distance in the description of the citrus fruit of your choice.

A citrus tree will only express its full potential if it is planted in the ground.

If the minimum temperatures in your region do not allow it for the varieties you have chosen, you will have to keep them in pots.

Trees will lose some of their hardiness by staying in a pot. In a classic pot, with rigid walls, the roots are concentrated against these walls and will be very exposed to frost.
In an Air-Pot, the roots are distributed throughout the volume and will be more protected. In this case, the loss of resistance to the cold can be estimated at 5 to 6 degrees.
The best solution is to shelter them over winter in a greenhouse maintained between a minimum of -5 degrees (at night) and a maximum of +10 to +15 degrees (during the day), then take them out in spring.
Alternatively, surround the pot with a double layer of thick jute. Add thick mulch to the soil around the pot. If the size of the tree allows it, apply a TNT veil of 19gr/m2 (minimum) without sticking it on the leaves. Use 4 sticks to build a box around the plant, keep the veil on the ground with large rocks or bricks.

All the trees sold on this site are raised in Air-Pots (see the manufacturer's website), specially shaped pots that guarantee the integrity of the roots in the long term.

As the tree grows, it should be transplanted to a larger Air-Pot. In theory there is no limit to the size of the Air-Pots, the system being designed to be expandable. In practice, it will become difficult to move the trees quickly because of their weight. A reduction pruning each year will therefore be unavoidable, unless you can plant directly in the greenhouse.

Note:
Don't throw the Air-Pots away. You can reuse them or return them to us.