no. 7.406

Flowers for Mountain Communities

Quick Facts...

• Consider the length of the growing season, soil characteristics and exposure before selecting flowers for mountain gardens.
• Be cautious with late-blooming flowers, as they may not have a chance to bloom in short-season climates.
• Choose plants that are hardy to USDA zones 2 to 4. The lower the zone, the hardier the plant.
• Amend your soil for best results.

This fact sheet discusses biennial and perennial non-native flowers for mountain areas above 7,500 feet as well as highlighting some native plants not covered in fact sheet 7.242, Native Herbaceous Perennials for Colorado Landscapes. Ground Covers and Rock Garden Plants for Mountain Communities are covered in fact sheet 7.413.

For more information on gardening in the mountains, refer to fact sheet 7.244, Colorado Mountain Gardening Basics.

Selection

The flowers listed in Table 1 have been selected to thrive in mountain gardens. When selecting plants from this list, match the cultural needs of the plants to the garden site in which you intend to plant. Cultural factors to consider include soil texture and organic matter content, moisture and drainage, light exposure, and microclimate. ‘Warm’ or ‘hot’ microclimates are usually found on the protected south sides of buildings, against stone walls, or on south-facing slopes. Plants listed as easy to grow are most suitable for new gardeners. Plants listed as ‘aggressive’ can spread widely in the landscape, especially under conditions of higher soil fertility and moisture. Where information was available, we included whether the plant is resistant to deer and rabbits. Please be aware that no plant is entirely resistant if an animal is very hungry; also be aware that there may be geographical differences in what animals will eat.

When purchasing plants from a nursery, garden center, or greenhouse find out where the stock was grown. Stock originating from southern and Pacific Coast sources may be less hardy. Where possible, select nursery stock originating from northern areas especially for marginally hardy plants. Look for healthy plants with a strong but not root-bound root system.

Establishment

In mountain areas, the best time to plant flowers is either immediately after the last frost (particularly for borderline hardy plants) or during the rainy season. Avoid the temptation to buy plants too early because most nursery stock is grown below 6000’ and the new growth may not be hardened enough to withstand the conditions at higher elevations. You may have to maintain plants for several weeks if you buy too early, which can cause the plant to decline. Before planting, acclimate plants by gradually exposing them to longer times outdoors in mountain conditions over a period of several days or weeks. This process is also known as ‘hardening off.’ If plants are grown outside and are from local nurseries, this is not necessary.

Soil preparation is often the key to growing healthy plants in the mountains, particularly for non-native plants. Native plants are often adapted to leaner soils (lower in organic matter), and may ‘flop’ or have a shorter life span in well-amended soils.

For optimum growth, most mountain soils benefit by amending with organic material such as compost, alfalfa pellets, aged manure, or a combination. If the original soil is decomposed granite, extensive amending will be necessary to achieve an organic soil, or even a moderately organic soil as is required by some plants. If the original soil is clay, amending with organic matter or creating and planting on a berm can help to create the well-drained soils required by many garden plants (although in poorly drained soils it is best to add some organic matter each year, rather than all at once, in order to avoid salt buildup). For more information on amending soils, see fact sheet 7.325, Choosing a Soil Amendment, or 7.244, Colorado Mountain Gardening Basics.

Snow cover is an excellent mulch, allowing root growth to occur even during some periods of the winter. Encourage snow to drift over the root zone of plants by using temporary snow fences a few feet from more tender plants on the upwind side of the plant.

¹ L. Potts, Colorado State University Extension agent Eagle County; I. Shonle, Colorado State University Extension agent Gilpin County. Special acknowledgement to Sharon Balius, Colorado Master Gardener in Eagle County. 4/08.

Colorado State University, U.S. Department of Agriculture, and Colorado counties cooperating. CSU Extension programs are available to all without discrimination. No endorsement of products mentioned is intended nor is criticism implied of products not mentioned.

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