By: Danielle Frohn, Assistant Horticulturist
Are you new to gardening? Or maybe just new to the area? There are a few quirks about gardening in Salt Lake City and the Wasatch Front that you should be aware of before getting started. The climate, soil, and relative lack of precipitation can lead to minor setbacks or distress to your garden if you are unprepared.
Life in Utah can be dramatic, especially along the Wasatch Front with its incredibly dynamic landscape. Utah is the second driest state in the nation, receiving on average 18 inches of precipitation each year—most of which comes as snow. Only a small percentage of that precipitation falls during the summer months when the plants need it most. Intense sunlight in summer means that some plants, even full-sun plants, will benefit from a bit of afternoon shade. On top of that, we get the opposite during winter, with freezing temperatures and gray, overcast days.
The Wasatch Front stretches along the Wasatch Range of the Rocky Mountains from Brigham City in the north to Nephi in the south, and includes the metropolitan areas of Ogden, Salt Lake City, and Provo. USDA hardiness zones in the region vary between 6a and 7b, with minimum temperatures ranging from 10° to -10° F. Hardiness zones are based on the average annual lowest winter temperatures, divided into 10° F increments. To find out your specific hardiness zone, go to the interactive map created by the USDA Agricultural Research Service and enter your zip code. You can access this map at: http://planthardiness.ars.usda.gov/phzmweb/.
In addition to weather, you should also consider the soil. Soils in the Wasatch Front range from sandy to clay and are typically alkaline (pH higher than 7). Alkaline soil can impact the health of some landscape plants due to the reduced availability of some nutrients, especially for plants not adapted to high pH soils. The most common example of impacted nutrient availability seen locally is iron chlorosis, or yellowing of the leaves due to iron deficiency. While iron chlorosis is the most common, other nutrients may be deficient, such as manganese or zinc. Nutrient deficiency happens because a particular nutrient becomes immobile (thus unavailable to the plant) in high pH soils. Iron chlorosis can be temporarily alleviated by use of iron chelates and other soil amendments, but a better long-term solution is to take advantage of the many amazing plants that are already well-adapted to our soil conditions.
When you step into your garden and begin to make a plan, keep these climatic and soil traits in mind. There are many wonderful plants that thrive in this environment, as well as strategies to help them survive challenging conditions. To best deal with our dry climate, designing and installing water-efficient gardens is extremely important. You should also water in the early mornings or evenings after the sun has gone down. Because of the cooler temperatures, the water is able to soak into the soil better and not evaporate before hitting the ground. Grouping plants according to their water needs (hydro-zoning) will help maximize your water efficiency by delivering the right amount of water to each plant.
Keep an eye on how moist your soil stays. The best test is to feel the soil; it can be a little dry on the surface but may still be damp underneath. Most plants can tolerate the soil drying out a bit between watering. Also, be mindful of the watering needs of your plants when checking your garden’s moisture as some plants like to be dry (cacti, succulents, many native plants) while others like to have consistently moist soil (bamboo, impatiens). For more information, check out the Waterwise Gardening fact sheet on our website.
Before you head to the nursery to begin picking out plants, there are a few things to consider prior to buying and planting—frost dates, plant hardiness, sun tolerance, and soil drainage. The average last frost date in spring is May 7 (around Mother’s Day) and the first frost of the year is usually around October 17. With that said, a snowfall in late spring or early fall is not unusual, so be watchful of forecasts and be prepared to cover your new plants with frost cloths if needed. To make sure the plant you fell in love with at the nursery can tolerate our cold winters, look for its hardiness zone, and whether it’s perennial or annual. An annual only lives for one growing season, while a perennial lives for two or more years. Perennials and woody plants that are not cold hardy should be brought inside for the winter. If a plant is marginally hardy, you can try to overwinter it in the garden by adding mulch for extra insulation or planting it in a warmer microclimate such as close to the foundation of a heated structure. "Marginally hardy" means the plant is hardy to one zone warmer than your area, which along the Wasatch Front is typically zone 7 or 8. Find more information on Microclimates on our website.
A growing issue along the Wasatch Front is the escape of ornamental plants into our foothills and canyons that have become invasive, noxious weeds. When working in your garden or preparing a new garden site, it is always wise to equip yourself with knowledge of these plants, the best way to control them, and any safety measures needed when dealing with those that are toxic. In addition, it is vital to be aware of what you plant in your garden and its potential to become invasive in our natural environment. Find out more information on invasive and noxious weeds at Noxious Weed Field Guide for Utah.
Make sure to have fun and play around in your garden, try new things, and enjoy becoming a gardener in the Utah. It’s okay if it takes a few tries—it’s okay if some plants fail. Just remember to check the soil, water, and sun, and keep trying.
If you would like to learn more, here are some classes that might interest you: Gardening in the Wasatch, Garden Maintenance, Fall Garden Maintenance