Global warming is forcing us to adapt our gardens to new climatic conditions. Here is a non-exhaustive list of Mediterranean-type trees and shrubs that we can start trying to acclimatize north of the Loire. The weakness of these plants may be frost resistance. For while it’s much warmer in summer and no longer rains, in winter it’s always freezing.
Apart from the Grenadier and the Amandier, I’ve seen all these trees thrive in Brittany. The normal climate here is mild in winter, but not Mediterranean either, and we often have heavy frosts from February to April.
I wanted to write this article because I myself am looking for new plants that are better adapted to the new climate. My garden is typically a heather garden, but year after year I see plants dying of thirst and heat. For example, I’ve lost most of my heathers, which usually grow on granite with little soil. But last summer (2022), they simply roasted in the sun. The same goes for hydrangeas, which burn in the sun and suffer from thirst in the shade.
So here’s my list of 20 trees to test north of the Loire.
1 – Judas tree
You may have seen this beautiful tree in Spain. It’s a medium-sized tree. There’s one in my parents’ garden that has remained quite small. Perhaps because of the quality of the soil or the depth.
It grows well by seed.
2 – The olive tree
Olive trees are now to be found in almost every garden in Brittany, where they thrive. We started seeing them 20 years ago and they’re still there!
3 – Oleander
Oleander is sensitive to the cold and will appreciate a small spot sheltered from cold draughts.
4 – The mimosa
To be tested at home. In Brittany, it has always grown well. There was a huge one in my grandmother’s mini garden. It froze in the 80s. But since then, all the mimosas have grown back!
It can become invasive because it trails. There are now many varieties of mimosa. Be sure to ask about frost resistance before choosing a tree.
It is sometimes considered an invasive plant, but perhaps it is simply better adapted to the new climate?
5 – The holm oak
The holm oak is now planted for timber production in Brittany. Here, it grows very large. So don’t be fooled by the small trees you may have seen on the Mediterranean coast.
It has the disadvantage of reseeding itself everywhere and looking a bit like a holly when young, with prickly leaves.
As with the mimosa, the question arises: invasive or simply better adapted?
6 – Cistus
Its lifespan is fairly short (10 to 15 years) and it tends to freeze. But it grows fast, so you can replace it when it gets ugly. Very easy to cut.
7 – Cytise (Laburnum)
A classic that grows really well around here. You can grow it on a single trunk or leave it free to form a large clump of several trunks around 3m high.
Take a shoot with a few roots at the foot of a clump of laburnum.
8 – The almond tree
I’ve never seen one around here. This tree likes heat and sun. But even if it doesn’t produce fruit north of the Loire, maybe it will produce flowers?
9 – Bougainvillea
Superb, but even more fragile than oleander. To be tested in full sun and sheltered from the wind!
10 – Cypress
For a Mediterranean touch in the garden.
11 – Le Figuier
Fig trees are very sensitive to frost. Try to find a grower in your area who will suggest a variety suited to your region.
12 – The Grenadier
Not yet tested!
13 – Albizia or silk tree
You can see this beautiful tree all over France now. It looks pretty hardy. According to Promesse de Fleur, it can withstand temperatures down to -12C°.
14 – Callistemon
Under ideal growing conditions, callistemon can reach 8 to 10 meters. But if it’s cold in winter, it may stay smaller? They can be seen in Brittany, but in bush form.
15 – Le Cordyline
Red cordyline is less resistant than green. All my reds froze this winter.
Green cordyline is easy to propagate from seed.
16 – Le Lilas des Indes
It’s everywhere in municipal flowerbeds in Brittany. I think it grows too slowly.
17 – Les Genêts
That’s easy. Yellow, red, yellow and red. Lasts 3 or 4 years.
18 – Shrubby Veronica (Hebe)
Speedwell, a large flowering bush that’s a bit old-fashioned. We used to see a lot of them in the 70s, but as they tend to spread, people have removed them from gardens. They can spread over 3 or 4m2 after 15 years. So you need to leave a bit of room.
19 – Leptospermum
I love this shrub. I had one in a former garden but not here yet. I don’t know how big it’s going to get but I love the way it blooms.
20 – Le Tamaris
A typical seaside shrub. Here, it grows along the beach. It tolerates sea spray well. It also looks great in gardens. It’s difficult to grow other plants at its foot. I think it consumes all the water available. It has to store it. That’s probably why it stands drought so well.
21 – Citrus fruits
Some citrus fruits, such as those grown in Spain or the south of France, can be tested. Tropical citrus such as Kumquats are more difficult to acclimatize, as they like heat and light all year round.
Read more: Growing Kumquat in Brittany
Here are two more articles on adapting your garden to global warming: 22 waterless perennials in summer and 18 summer waterless flowering shrubs.
