Gardening in the Foothills and Higher Elevations of the Black Hills

 Tips from the Masters



Gardening in Custer County can truly be a challenge for many reasons that include short growing seasons, plant predation by deer, often-limited water supplies, and a wide variability of growing conditions from location to location, and also year to year. 

The Black Hills and surrounding area are part of the Northern Plains, which has an ecological classification of semi-arid, short grass prairie. The average annual precipitation ranges from 13 to 17 inches.   This precipitation can fall as snow during the winter or spring months, and thunderstorms or sometimes hail during the summer and fall.  Spring storms that dump two feet of wet heavy snow in April and summer thunderstorms dropping over three inches of rain per hour are somewhat common occurrences here.  Prolonged dry spells are also common in the local area.  Experienced, local gardeners consider the gardening season to be from early-to-mid June to the end of September, yet are always mindful that a killing frost can occur during any month of the year.   Taking into account the local conditions and selecting hardy plants that fit these conditions must be foremost in a gardener’s mind. 

In order to successfully garden in Custer County, it is essential to have a good, solid plan so you don’t waste time and resources.  There are a number of resources available to help you get started with your gardening adventure in Custer County including SDSU Extension Service, Custer Master Gardeners, Mile High Garden Club, and local nurseries.  Generally, it is best to stick with a USDA hardiness zone rating of 3 or 4 when selecting plants for your garden.  Beware of buying plants at the “big box stores” as they don’t always carry species that are appropriate for the local conditions, thus reading labels and only buying plants that are “drought tolerant” and “cold hardy” is a must.  You will have better luck shopping at the local greenhouses because they should know what grows here. SDSU Extension also has some good publications about locally adapted trees, shrubs, and flowers. 

During the planning process, make sure you have your soil tested by sending it to an accredited soil testing lab.  Materials and information on soil testing are available at the local Extension office.   Black Hills soils are often heavy with clay and require amendment with organic material such as manure, compost, grass clippings, etc. to lighten them up.  Some local gardeners spread the organic material over the soil as mulch and don’t work it in, but instead let the worms and bacteria in the soil do the work of breaking it down.    By doing this, you also improve the water retention by having the absorbent layer of organic material on top of the soil.  Mulching needs to be a yearly task because the soil can only take in so much new organic material per year.  Yearly application is also necessary in order to continue building and replenishing the soil with nutrients that are lost to growing plants.   

Vegetable gardening in the Hills is tricky business.   You can attain success in the outdoor garden by planting the hardier crops such as green beans, peas, lettuce, scallions, parsnips, zucchini, and beets.   However, with many of the more delicate crops such as tomatoes, cucumbers, and peppers, local gardeners have had better luck with container gardening, cold frames, or greenhouses.  The portability of the containers make it easier to protect the plants from frost, hail, and deer.  Again, choose plants for their short number of days to maturity and high elevation qualities.  Some local gardeners who are brave enough to plant their tomatoes in the outdoor garden don’t plan on picking any that are ripe. Instead, prior to the first frost they either pull the whole plant or pick the fruit and let it ripen indoors.   Others use “wall-of-water” mini hothouses or row covers for frost protection with varying amounts of success.

Another challenge of gardening in Custer County is the abundant and hungry deer population.  There are many plant varieties labeled “deer resistant” but none “deer proof.”  Late in the season when herbage in the woods has dried up, the deer around here will eat just about any yard plant including those that are supposed to be somewhat toxic, like foxglove (Digitalis species) and rhubarb.   There are really only two effective ways to deal with this problem, which are spraying deer repellent or fencing.   Deer repellent mixes are available as commercial products or there are quite a few recipes for home concoctions.  The key to both is to start using them early before the deer acquire a taste for your plants.  Commercial mixes tend to be more expensive, more potent, and longer lasting, but there is also a loyal local following of this “home brew” recipe.  The idea is to train the deer that your garden is a repulsive and smelly place.  The odor from this brew dissipates to human senses within 24 to 36 hours.

Liquid Deer Repellent

Mix together:  ½ cup milk, ¼ cup salad oil, 1 egg, and 1 tablespoon liquid detergent.

Keep the mixture in a closed container in a warm place for 2 weeks or until putrefied.  Add to 1 gallon of water and mix well.  Liberally sprinkle with a watering can on and around plants you want to protect.  Allow enough time to dry before rain or other watering.  Repeat the application in 1 week, and repeat every 2 weeks during the growing season.  You might want to mix a double or triple batch at one time.

Even though fencing is visually intrusive, a properly constructed deer fence is a surefire way to protect your garden.  The key is to make it tall enough (at least 6 feet) and to anchor the bottom so the deer can’t get under it. 

Welcome to the challenges of gardening in the Black Hills and may you have success!

This article was written by Helen McGranahan (Custer), with contributions from Doug Hesnard (Hermosa), Tom Thorson and Rob Simon (Hill City) and Linda Markegard, Jane Faulstitch and Ingrid Grimes (Custer).


Miss Gardening? Grow Green Beans Indoors This Winter


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For gardeners who just can’t stand to keep their hands out of the soil for any length of time, growing food indoors in containers can be a great pastime during the winter months.


Green beans are a relatively quick-growing vegetable that can be grown inside your home and also look quite beautiful, as well.


Plants that you are growing indoors can be started any time of the year, but you still need to remember that they have certain environmental requirements. Green beans need plenty of light, so you will need to place them in a part of your home where they can get a minimum of six hours of sunlight each day. Alternatively, grow lights can work if you do not have a window that gets enough sun.