City Guides » Green

Planting Defensively

On growing turf and outsmarting wildfires


At the end of summer, gardeners do some of their best learning. We rehash what transpired over the growing season in our gardens and ask ourselves questions like: Did I do this right? Could I have done that better? Should I try something different? Getting those questions answered, and learning from mistakes, is what turns ordinary plant lovers into great gardeners.

Bob J. of Kuna wonders: When is the best time to seed grass?

September is prime time to seed a new lawn or repair bare spots in an existing turf, Bob. The types of grass we grow around here--the cool season grasses--like Kentucky bluegrass, perennial ryegrass and turf-type tall fescue, prefer cool growing conditions to get their start. Both spring and fall are good times to seed, but fall gives you and the new lawn an advantage because fewer weeds will sprout up with the grass seedlings.

Christa L. of Eagle asks: Every year when the foothills dry out, I start worrying about fire. Is there a way that I can protect my home from fire using plants?

Luckily, this has been a pretty mild fire season, but creating a defensible space or fire barrier around your house is an important step to take before wildfires become an issue. Most fire prevention research suggests that you clear a 30-foot area around your house by removing highly flammable plants like conifers (cone-bearing evergreens) and reducing ways that fire can easily reach your home.

In town, we traditionally landscape by clustering plants around a house's foundation, often using resinous evergreens like juniper, spruce or yew, but this isn't a good idea in areas susceptible to fire. On fire prone properties, it would be better to place trees and evergreens further away from the house. Also, it is also a good idea to eliminate "fire ladders"--plants of ascending heights that provide a continuous fuel supply from the ground up into a tree canopy or up into the eaves of a house. Another type of fire ladder is on the tree itself. Trim the lower branches on trees to help lessen the chance of a ground fire climbing up into a tree. Overhanging tree branches can drop burning debris onto a structure during a fire; think fire resistant roofing material and remove overhanging limbs within 15 to 20 feet of a roof. Even the mulching materials you use in the landscape beds have to be evaluated with a concern toward fire safety. Use stone mulches instead of wood chips.

Regular home and landscape maintenance is crucial to good fire prevention. Make sure your irrigation system is working correctly to water turf and other plants adequately. Cut dry grasses short that border your yard, if you're in the foothills. Remove dead branches from trees and shrubs, and clear leaf litter from under plants, as well as from the roof and gutters.

Don't worry, having an adequately cleared area around your house doesn't mean your property has to be devoid of plants. Plant placement and smart plant choices are what makes firescape plans work. Consider altering the arrangement of existing plants by putting more space between plants or planted beds and the house. This will help prevent horizontal fire paths within the landscape. That's where flames can move quickly along the ground from plant to plant due to close proximity.

A greenbelt of grass and other lush, low growing plants around your house can help keep fire at bay. You wouldn't know it, but adequately watered turf can act as a high moisture firebreak. A few years back I witnessed this very thing after a fire in the foothills near Star, Idaho. The wildfire, which had already burnt a shed, fence posts, sagebrush and dry grasses, stopped at the edge of a lush green lawn surrounding one fellow's place and went around his house. Ah--the power of green!

There are many plants that are said to be "fire resistant," but that term may be misleading since all plants can burn if conditions like wind, fire temperature and fire speed are just right, but it doesn't hurt to use plants that actually are able to absorb much of the heat from a fire and take a long time to ignite. Succulents like stonecrop (sedum), for example, make excellent firebreaks because of their thick, moisture-laden leaves. By selecting vegetation better suited to withstand fire, and by making wise choices regarding the placement of trees and other plants in your landscape, you can develop a beautiful firescape that will both complement and protect your home. Check the Internet for more info on fire resistant landscaping ideas.

Suzann Bell is a horticulturist with the University of Idaho Extension in Ada County. Send gardening questions to Suzann c/o Boise Weekly or