Tricks of the Trade: High Altitude Gardening
June 24, 2011 § Leave a Comment
AN EDIBLE INTERVIEW WITH JOHN WICKMAN
If you want the skinny on edible gardening in the southwest, spend a few minutes with John Wickman. He’s been gardening for over 30 years in Colorado and is the owner/operator of Native Roots Gardening Center in Durango. Our plot of paradise here in the Southwest is a far cry from the throw-a-seed-in- the-ground-and-it-will-grow-like-crazy climate of other regions. But those with a bright green thumb like Wickman manage to grow vegetables and beyond in this harsher climate. His skills have even rubbed off on family members. His daughter grew hundreds of pounds of produce last year for a school project—then donated it all to the Manna Soup Kitchen. Here John shares some insight on gardening at high altitude.
What actually constitutes “high altitude”?
JW: Anything above 6,500 feet. Even the difference between Durango and Denver is huge. High-altitude gardeners have to contend with a much shorter growing season; we have three months here whereas Farmington has five months, Denver has five months.
What do you think is the biggest challenge of high altitude gardening, and how can we overcome it?
JW: The nighttime temperatures. They are in the 40s, and even though daytime temps are high, the soil still cools down a lot at night. Soil temperature drives a lot of plant metabolism; when soil temps drops below 55 degrees, plants stops growing. I suggest frost guard, which is a white fabric that helps a lot with maintaining nighttime temps. Basically you put it over the top of soil and plants grow underneath. It’s really lightweight, and as plants grow they push it up, then you can pull it off mid-July. The other option is to build a cold frame, or some type of greenhouse, which would obviously extend the season.
Is the soil here problematic and how can a new gardener work with it?
JW: The soil above us is high in minerals, like in Silverton and Telluride. Down here (in Durango) we have fairly fine clays because of the sediments coming out of the mountains, so the pH is going to be different depending on where you are. Because plants are sensitive to the pH, it’s good to get your levels tested. You can pick up soil sample kits at the extension office in Durango (2500 Main Avenue) or at most gardening centers. Once you know what your pH is, we give recommendations on how to amend the land for growing certain crops with organic matter based on those results.
* According to the Colorado State University Extenstion Office: “ pH can be described as the measure of acidity or alkalinity of soil. pH is measured on a scale of 1 to 14 where 7, which is neutral, is the optimal level for most plants. Numbers lower than 7 are considered acidic and numbers higher than 7 are considered alkaline or calcareous (high in calcium carbonate). Garden soils in Colorado that have never had amendments added may have a pH value of up to 8.5, which is higher than most plants can tolerate.”
Are there certain pests gardeners in the area need to contend with?
JW: By far the most complaints we get are deer and elk. Build a fence. Or you can get repellants that are organic and made out of eggs, or some made from blood, which instills fear in the animal rather than stinks them out. By far the biggest pest is aphids. But the good news with climate change is the predatory insects that never used to be here like praying mantis, lacewings, parasitic wasps, now over-winter here. These beneficial insects help keep the insect pest population down.
Are there certain seeds or plant breeds to look for that are specific to the growing season in high-altitude areas?
Yes. There are all different vegetable gardening plants that have varying days to harvest. Some tomatoes you can get to mature in 60 to 120 days, while most heirlooms take 100 to 120 days, which is unfortunate because heirlooms are better. Fast-maturing tomato breeds include Siberian, Early Girl or Celebrity—there are quite a few that have been bred to ripen in a shorter amount of time. There are also some beans, squash varieties, and even cabbage (that mature quickly).
What are some specific edible plants that might be considered “no-fail” and easy to grow for someone who is looking to get into gardening in our area?
The easiest would be some of the lettuces, beets, broccoli, Swiss chard, zucchini. Hard ones would be watermelon and cantaloupe because nights are too cool, so they produce fruit but the fruit is too small. They grow terrific cantaloupe out in La Junta, so I say buy those at the store and save garden space for what is productive. My advice is always to be patient, experiment and don’t get discouraged because it’s difficult.