By Ginny Gelbach, Colorado Master GardenerSM and Carl Wilson, Cooperative Extension Agent, Colorado State University Cooperative Extension, Denver County
Adapting to life in a new place can be challenging for newcomers, but the plants in your new garden face even greater challenges.
Welcome to the state with an altitude! Colorado is what geographers call a high, semiarid steppe.
As with similar places in the Andes and Himalayas, humidity in the Rocky Mountains is low and rainfall is infrequent. Winds are drying and temperatures can fluctuate as much as 90 degrees in a 24-hour period. Along the Front Range, it can snow in May or September.
Unlike people, plants don't have the advantage of finding shelter to protect them from climate extremes. Plants must be tough to survive here, and gardeners must be astute enough to help them along. Your choice of plants, locations for planting and techniques for manipulating their growing environment will make the difference between gardening success and failure.
So what's a transplant like you to do if you want to grow a garden? To begin, plant new transplants and seeds in a prepared soil. Dig in a one-to-two inch layer of compost, sphagnum peat or aged manure. These amendments will loosen tight clay soils and hold moisture in sandy ones. The improved soil promotes abundant root growth and healthier plants.
New seeds and transplants are much like newborn humans; they need protection from Colorado's intense sun and winds. Just like throwing a blanket over the baby stroller, cover new seeds with garden row-cover fabric. By preventing the top of the soil from drying out, fragile seedlings will not die between the time you water in the morning and evening.
Row covers also shade new transplants. When you first bring the transplants home, shuttle them in and out of the house or other shelter for the first few days. During the day, place them in an outdoors protected area, such as a porch. This gets them accustomed to the dry air and wind. Then transplant, throw the row cover over them and anchor the corners with U-shaped wire pins inserted into the soil. You also can use rock weights.
The beauty of row cover fabric is that you can water seeds or transplants through it. After seeds are germinated and transplants acclimated, remove the fabric and your garden is off and growing.
To choose permanent shrubs and trees, plow through localized information and heed the advice of native gardeners. Broadleaf evergreens, such as mountain laurel and rhododendron, tend not to grow well here. The alkaline soil, low humidity, dry winds and intense sunlight hinder their growth. Better shrub choices include Oregon grape holly, juniper, potentilla, viburnum, lilac, ninebark and others.
Tree choices also must be made carefully. Snow is great for skiers but disastrous to tree limbs. Because of Colorado's tendency for early or late wet snows, tree limbs often break from snow loading. Plant trees that are less brittle, but be patient, as these types take longer to mature. Recommended trees include Norway maple, linden, swamp white oak, honeylocust and green ash. For small trees, try Russian hawthorn, Amur maple, Shubert cherry, Callery pear, Japanese tree lilac and serviceberry.
When relocating, newcomers are sensitized to the real estate axiom of "location, location, location." The same is true of plants. Carefully consider exposures for planting. North and east exposures are cooler than those to the south and west. Some plants will tolerate the hot afternoon sun of west exposures and others are best located in east facing locations that receive gentler morning sun.
You have moved to a beautiful and unique place. Colorado's low humidity makes cold days seem less cold and hot days less hot. It also discourages many landscape plant diseases. In spite of some unique gardening challenges, you can grow a beautiful healthy lawn, abundant veggies, eye-catching flowers and trees to shade you from summer's heat.
Dig in, adapt to a new gardening environment and be flexible. Enjoy your Colorado garden!
Further help is available. Visit local nurseries. Talk to neighbors about their garden successes. Read Colorado garden books and local newspaper garden stories. Make use of your local Colorado State University Cooperative Extension office. Ask for CSU Fact Sheet 7.220.
Photo: Judy Sedbrook
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010