How to Garden Successfully at High Altitudes

Gardening at altitude: it’s a challenge, but still quite doable. Photo: alikskr@gmail.com, depositphotoss

By Laurie Fourniaudou

Between 2,000 and 5,000 feet (600 and 1500 m) above sea level, gardening isn’t as easy as at lower elevations. Everything becomes just a bit more complicated. However, that doesn’t mean you can’t grow copious quantities of delicious vegetables. Nor beautiful flowers. Nor even trees. The key to gardening success at high elevations? Adapt to what the local environment allows you to do.

So, how do you grow a high-elevation garden? Read on and you’ll find out!

Specific Factors About Altitude That Affect Gardening

Climate

The first particularity of high-altitude gardening is. . . the climate. That’s not a huge surprise, I’m sure. Most people know that the higher you climb, the colder it gets.

How cold actually varies depends on where you live. It can be more pronounced in some regions and much less in others. In Europe, where I live, the climate is actually rather uniform, varying fairly little. . . except in the mountains. In the US and Canada, the climate varies much more drastically. Then even more in the mountains. You’d do best to consult a hardiness zone map to find out to learn your local hardiness zone.

Be that as it may, in the mountains or at altitude, gardeners encounter three main problems:

• Winters are harsh and treacherous, with plenty of snow, frost, cold wind and damp fog.
• Frosts come late in spring and early in fall.
• Temperature differences between day and night can be significant.

Personally, I live in a small perched village (Montaillou) high up in the French Pyrenees at an altitude of 4,265 ft (1300 m). The winter of 2021–2022 wasn’t actually all that cold—the lowest it got was 21°F (-6°C)—, but some years it’s much colder. However, we still had nights below freezing from early November (some years, even as early as October) until the first days of spring, with several bouts of heavy snow. It’s like a climatic yo-yo here: freeze, thaw, freeze, thaw. (If you read French, you can follow my battles with the local climate on my weblog at Le Potager d’Aillou ?.)

Even in summer, night temperatures can drop precipitously; yet days can certainly be hot enough! Such is the way in mountains!

As you can imagine, that subjects plants to difficult climatic conditions.

In almost all high-elevation areas in the Northern Hemisphere, the main gardening period is from May to September/October.

Lay of the Land

In most lower altitudes, the land is fairly flat. Growing plants and gardening there are much easier.

But when you climb more than 2,000 ft (600 m) above sea level, you have to take into account the irregularity of the terrain into account. And most often, the terrain is naturally steep. . . and difficult to work with.

Slope is everywhere where I live. Valleys, hills, even fields: they all have a distinct slope. Growing a vegetable garden or flower bed can seem complex in these conditions. Plus very physically demanding! However, there are simple solutions you can use to make your hobby easier.

How to Overcome the Peculiarities of Altitude?

Landscape for Success

The first solution is to try to turn the disadvantages in your favor.

For example, to compensate somewhat for the difficult climate, I recommend that you orient your garden so it faces south or southwest. That way, more of the plants will receive a maximum of sun and warm up a bit earlier on a cold morning. Your plants will appreciate the gentle rays of the sun beaming down on them.

To adapt to an irregular terrain, there’s nothing better than installing terraces. Yes, it’s back-breaking work, but you only have to do it once. And with terraces, you can hold on to your soil (there’ll be much less erosion) and your water (most rainfall and snowmelt will percolate into the soil rather than quickly flowing away). And terracing also leaves a flat surface that’s easy to garden in.

Look at the photo of the rice paddies above. It’s visually the same principle. Make your garden into a sort of gardening staircase made up of a series of flat garden beds and you’ll find gardening just got a lot simpler.

You can create terraces by using retaining walls of stone or brick, interwoven branches, boards, etc. All three structures hold the soil in place and allow you to garden on a flattened surface.

Of course, nothing prevents you from gardening on a slope. But your efforts will be less easy to carry out. Watering, for example, is more complicated, as the steeper the slope, the more water runs off without helping the garden. And do be forewarned, too, that gardening on much more than a slight slope can be very hard on the leg muscles! But then, just getting around a garden on a mountain is hard on the leg muscles!

Grow Appropriate Plants

In a mountainous region where temperatures are colder, you will have to adapt your choice of crops. Some trees, flowers or vegetables simply won’t take frost. So, crops you see friends growing in the valley right down below, really not that far away, often won’t do at all. It’s like an entirely different world down there!

By exploring your environment (general nature, type of soil, etc.) and learning to understand it, you’ll come to know what to plant and what not to plant. By talking to gardeners growing under similar conditions to yours, you’ll learn even more. Therefore, start by planting locally popular plants. These will vary in different regions and countries. You have to adapt to nature, not try to force nature to adapt to you!

I suggest you start with species known for their ability to succeed at high altitudes. You’ll find it much more complicated to grow tender vegetables—tomatoes, eggplants, cucumbers or melons—at high elevations. The same goes for trees and shrubs: favor varieties that have proven themselves adaptable to mountainous terrain.

In altitude, you also need to look into fast-maturing varieties rather than ones that are slow to mature. The vegetative cycle of these quick-maturing varieties is simply speedier. As the gardening season in altitude is often limited (often only from May or June to September or October in the Northern Hemisphere), working with fast-growing plants is certainly an advantage. You won’t have to wait several extra weeks to harvest, either.

Many seed packs include a helpful note: “days to maturity.” In mountainous terrain, 70 days is acceptable, but 55 days is even better! 150 days? That’s very, very bad!

So remember, the lower the number, the better!

Protect Your Plants

One final thing: you need to think of supplying frost protection to your plants; that is, a barrier against cold and frost. As mentioned, at high altitudes frosts come often late in the spring (well into May or even June) and early in the fall (October or, worse yet, September).

In addition, the temperature difference between night and day also fluctuates widely. Yet, almost all plants prefer relatively stable temperatures. A drop of only a few degrees at night is fine, but when you need short sleeves and shorts to survive the day and a long pants and a thick coat, plus a wool hat and gloves at night, a lot of plants will be having trouble.

Gardeners at high altitudes should seriously consider installing a greenhouse or a hoop house (tunnel) for extra protection. Or a cold frame. For many tender vegetables, like tomatoes and melons, this is really the only way to proceed. It’s amazing how much warmth even a thin fabric can hold overnight, especially if the spot isn’t too windy.

And you can get a bit of a head start on the season simply by covering your earlier sowings and plantings with floating row cover shortly after you put them in the ground, leaving it on until there really is no more risk of frost.

Yet another way to counter the effects of cold winds and heat loss is to install hedges or windbreaks.

Finally, in the middle of winter, if a generous layer of snow covers your vegetable garden, don’t try to remove it thinking it will help the few vegetables that still remain in the ground. Snow actually protects them from frost. . . and is, furthermore, rich in nitrogen, releasing this precious mineral slowly to the crops as it melts.

What should I Plant in My High-Altitude Garden?

Best Vegetables for High Elevation Gardening

Here is a list of some vegetables and fruits that you’ll find suitable for a high elevation kitchen garden:

• Bean (wax, green, etc.);
• Beet;
• Broad bean;
• Broccoli;
• Cabbage;
• Carrot;
• Leek;
• Lettuce;
• Mâche (corn salad, lamb’s lettuce);
• Onion;
• Pea;
• Potato;
• Radish;
• Squash;
• Swiss chard;
• Turnip;
• Gooseberry;
• Strawberry.

Where I live in the Pyrenees, broad beans grow incredibly well. (Maybe you should try them!) We also have a bountiful crop of strawberries, green beans and snow peas every year. My partner and I were even self-sufficient in beets during the winter of 2021–2022.

However, to enjoy the delights of tomatoes, eggplants, peppers and other warm-climate vegetables, we don’t even try growing them outdoors. They go straight into one of our hoop houses! It’s either that or buy them from market gardeners growing at lower altitudes!

Helpful Hint: If you can’t grow something well, you shouldn’t grow it at all!

As for fruit trees, which ones grow well can vary according to specific local conditions, but the following generally acclimatize well to the cold temperatures encountered at high elevation:

• Apple;
• Cherry;
• Hazel;
• Pear;
• Plum.

Even with these “tougher than usual” fruit trees, do make sure you look for extra hardy varieties, ones known to be adapted to your region.

What About Flowers?

Just because you garden on a mountain doesn’t mean you can’t have beautiful flowers! Here are some suggestions of plants that ought to do wonderfully!

• Bellflower;
• Bergenia;
• Colchicum;
• Crocus;
• Iris;
• Lily;
• Narcissus;
• Primrose;
• Tulip.

And there are many, many more. Check your neighbors’ gardens and visit your local botanical garden. You’ll come away with dozens of ideas!

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Thank you for taking time to read my words today. And enjoy gardening way, way up in the mountains!

Translation and adaptation from French by Larry Hodgson