High-Altitude Gardening in the Rocky Mountains

A guide to high altitude gardening, vegetable planting, cultivating and harvesting in the Rocky Mountains.

Bundled onions vegetable gardening

Land that tilts like a roller coaster, a growing season of indeterminate length that may well include frost or snow, the absence of suitable directions on seed packets.


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Land that tilts like a roller coaster, a growing season of indeterminate length that may well include frost or snow, the absence of suitable directions on seed packets . . . those are some of the challenges that confront you when you plant a garden at an altitude of 8,000 or 9,000 feet. Even the back issues of that reliable old friend Organic Gardening seem to forsake you up where the air is thin and often chilly, and the prospects for high-altitude gardening success at first seem slim.

Still, if your green thumb really itches, bumper crops of splendid turnips, potatoes, cabbages, onions, garlic, and herbs can be yours without any real difficulty as high up as the timberline if you know how to grow them. And when you succeed, you get superb food along with the satisfaction of mastering the fine-tuning of one of the world's more exotic natural environments.

High-Altitude Gardening in the Rocky Mountains

I live in a small cabin on a mining claim in a national forest in Colorado, high on the eastern slope of the Rocky Mountains. And I find that my greatest pleasure in living here is learning the glories and subtleties of nature . . . and the ways of plants. I am surrounded by a wildness still intact enough to be an overwhelming force in my life, a wildness that makes me, as a gardener, want to learn what vegetables grow here best and most naturally, with the least amount of care and manipulation of the environment. The following approach to gardening has brought me a wealth of food and has helped me preserve the wildness a little longer. And it may tell other high-country gardeners how to do the same.

First, if you garden in that fascinating zone between 3,000 feet above sea level and the Alpine tundra where even trees don't grow, you must realize that the sunshine, moisture, temperatures, and soils all vary greatly over relatively small areas and short periods of time. This is because the land rises and dips steeply except for broad, high meadows that taper off into narrow gulches choked with willow and alder. Thus, every slope and its plants has its own relationship to the sun. Slopes facing north receive the least sunlight, and are cool and refreshing in late summer, when land tilted south is parched and dry. And slopes facing east get the morning sun, while those directed west are warmed even more by late afternoon rays.

A good example of this variability, and the adaptability it brings, can be seen in a healthy fruit tree that may grow in a sunny, protected crease of a hillside . . . but wouldn't have a chance of survival if it were planted ten to twenty feet away from that warm pocket.

My mountain garden is on a strip of meadow in a gulch, and is protected from high winds. It is wetter, and its soil richer, than surrounding hillsides, yet it is cooler at night and more subject to frosts . . . the cold air of evening rolls downhill like a river and into such gulches. So I have learned to plant only frost-resistant vegetables. And most of these vegetables outlast the neighboring meadow grasses in the fall to glow startlingly green in the midst of a dull gray and tan mountain landscape.

Another special factor for mountain gardeners to consider is the thinness of the atmosphere at high altitudes. This causes water to evaporate faster from the ground. You could say that the air itself provides less insulation for conserving water, so it is important to provide your own insulation for a garden in the form of a thick but lightweight mulch of dry grasses or straw. This mulch will keep the garden soil soft. Otherwise, unnaturally exposed by the digging up of mountain grasses as you spade the dirt, it would quickly become dry and hard. Old bedding from horse corrals is a good mulch for some purposes, and both nourishes and insulates. And such is the protectiveness of this covering, that in the bleakness of spring, the earliest green things you find will be safely hidden under the natural mulch of last year's grasses and wildflowers.

Next you must realize that Rocky Mountain soils lack the range of nutrients needed for many garden vegetables, so you have to dig in plenty of aged manure when you first clear a garden plot. For this purpose I recycle weeds, kitchen waste, and the refuse from the spring cleaning of my chicken coop . . . sometimes digging the manure and wastes directly into the garden soil, or composting it for a year. For additional nutrients I use the weeds I have pulled as mulch at the end of each summer.

Mountain soils, by the way, are often acidic at higher elevations, because they were created from granite rather than the alkaline sandstones and limestones of lower elevations, and because of the acid content of decomposing pine needles. Very acidic soils can be moderated by the addition of wood ashes. But if you heat with wood, these are easy to come by. The soils of meadows and aspen groves are richer, however, and less likely to be acidic than those near coniferous forests.

The first year I lived high in the Rockies I gardened without irrigation. The next year I used a 300-foot hose to take additional water from the spring to the garden when it was needed. But there is more rain at higher elevations in the Rockies than at lower elevations, so with careful observation and practice you will learn to plant a garden which is wholly sympathetic to natural conditions and that may not need irrigation. Hopi Indians, in fact, have farmed with great success for centuries without irrigation . . . in what at first glance appears to be barren desert.

At the start of the season you must anticipate the green of summer, which is a little hard to do after six or seven months of snow. That is when you learn that to garden successfully in the Rockies what you perhaps need most is optimism. Winter holds tight in March . . . while spring is only vaguely hinted at by the wetness of the month's snowfalls. Then in April the softening of the ground and the appearance of the purple Easter-egg-like pasque flower in the pine forests become more obvious signals of spring. Still, the landscape seems desolate compared with the brilliant green fuzz beginning to show at lower altitudes.

The actual length of winter, alas, is as variable as other conditions in the Rockies, so it is good to buy seeds, sets, and roots early. Then you'll have them when the first opportunities for planting come, and not find nurseries sold out.

Then come days in late April when the warmth of the air and soil surprise you like a miracle. Looking under the natural mulch of the meadow, or that of last year's garden, you find the soil has thawed and tiny green leaves are sprouting. That's when the gardener's heart within you begins to quicken. One native you may want to start with is the Umbelliferae family, which appears early and vigorously. Late April is the time to plant the domestic relatives in this family: parsley, carrots, and parsnips. Domestic varieties take all summer to mature, though carrots can be thinned and enjoyed the latter half of the summer. Fennel, similar in appearance to the wild whisk broom parsley, also takes all summer to mature and should be planted as early as possible. It is a licorice–like herb which flowers in June, and its leaves are great for salad and vegetable seasoning. You might say that its stalks and bases are a sort of Rocky Mountain celery.

Next there are leaf lettuce, spinach, turnips, and radishes, all of which will grow vigorously under a mulch through the snows and frosts of May and early June. Everything but the turnips will be going to seed by mid-July, so plan to make a second planting.

Leaf lettuce and endive are related to many edible wild species of thistles and dandelions that flourish in high, gassy meadows and along roadsides of the Rockies. Lamb's-quarters, a wild herb, is similar to spinach and springs up in disturbed soil at high altitudes. I weed it sparingly from my garden since it is delicious steamed or in salads.

Onion and garlic sets are also best started very early, while onion plants, like cabbage and broccoli (which must be started indoors and set out as plants to mature in the short growing season), are better set out when the possible wintry days of May have passed. That is also when you plant beet seeds . . . after the soil has warmed up a bit.

Sweet peas and edible pod peas have natural equivalents in many wild species (none too edible, some poisonous). Planted with the other early starters, they come up quickly and are rapidly climbing trellises by June. They need to be watered in middle and late summer to keep bearing after the first pods have formed, since they would provide an unpredictable harvest without irrigation.

In mid-May spring still seems far away to the casual observer from lower altitudes. The willow-like catkins of still-leafless aspen trees mature, hang loose on the trees, and fill the air with a white fuzz like gentle snow. But an old, lifelong gardener in our neighborhood assures me that this is the best time to plant potatoes.

Potatoes are not frost resistant, but they are an almost carefree crop with abundant yields even when frost touches down on a mid-August night, leaving behind wilted, dying plants.

A few tips on growing this crop: Buy genuine seed potatoes for stock . . . regular store potatoes have been treated to retard sprouting and will never mature properly. The larger the portion cut for starting, the more potatoes will be produced per plant. Plant the pieces about five inches deep and cover your rows with six inches of straw. In two or three weeks fat shoots of fuzzy leaves push up through the sod, but they must be protected from early June frosts.

Another valuable tuber for high-altitude gardens is the Jerusalem artichoke . . . like a potato, it can be boiled, baked, or fried, and it stores well. It is a close relative of the tall, ragged sunflower that comes up in abundance along mountain roads and ditches, forming thick, yellow borders when it flowers in August. And the Jerusalem artichoke grows almost as naturally, once it is introduced.

You may want to plant a corner of your garden with beds of perennial strawberries, chives, and garlic. Domestic straw berry plants adapt easily to mountain conditions, and wilt; strawberries can also be transplanted, and bear more heavily it cultivated. Rhubarb has been introduced by settlers and miners in moist gulches in our neighborhood, and it thrives untended like a weed. I have also established some spearmint plants along the damp runoff from the spring.

Keep your eye on what grows naturally around you. The native flora of the Rocky Mountains is also a good food source, and gives you clues as to what domestic vegetables will adapt best to high-altitude conditions. It also, incidentally, provides natural insect repellents. Once you learn the appearance of these plants in early spring, you can have them in your garden simply by weeding judiciously. Two common herbs that I allow to grow to repel garden insects are chamomile and sage. These can also be useful for tea as well as seasoning.

I have even experimented with a "greenhouse" for growing, vegetables that need more warmth than high altitudes and a gulch location provide. The greenhouse is an A-frame built with used 2 x 4's and covered with plastic. I have grown tomatoes, cucumbers, and zucchini in it as well as tremendous heads of lettuce and two–week crops of radishes.

Except for vegetables which thrive well outside, such as lettuce, the others have not done well . . . zucchini will not bear heavily inside the greenhouse because of the high humidity and the lack of pollinating insects. Perhaps a more favorable location than mine, one that is on a high, protected west-facing slope, may be better for growing these warm-weather vegetables at unusually high altitudes.

I am also satisfied with crops that grow here like weeds and in abundance. I have sweet lettuce and spinach to share with from the lowlands when it has grown too hot down there for these leafy greens. And the cool nights of the Rock Mountains give the same sweetness found in greens to the peas beets, turnips, cabbage, and other vegetables grown here . . . which, like fresh spring water, refreshes more than the most exotic produce brought in from elsewhere.

The final satisfaction of Rocky Mountain gardening comes in the tawny days of fall, when you dig potatoes, harvest the last of the root crops, and store what remains in cardboard boxes of sawdust or straw, to be stowed under the beds it unheated backrooms. Then you dry the herbs, and put chives and parsley in pots for your neighbors' kitchen windowsills. Finally, you cover the garden with dry grasses and dead weeds to rest protected till next spring.

As winter then approaches, you may linger outside to observe individual plants and their growth patterns . . . there is always more to be learned about the workings of nature that will be useful to your gardening efforts next year.

The real challenge of Rocky Mountain gardening, you will find, is not so much that of outfoxing nature and the difficult conditions she imposes. Mostly, it lies in harmonizing your efforts with hers for a healthy, abundant, deeply satisfying harvest.