In our American communities, one of the responsibilities of home-ownership is to keep the ground covered. Bare earth, like weeds, indicates lack of care. So then, how do we cover the ground? The cheapest, fastest, and easiest way is to roll out bluegrass sod. “Instant” landscapes can be accomplished with a supervised construction crew that knows little about plants. And as long as water was plentiful, bluegrass was the unquestioned solution.
Many people still accept the weekly mowing with gasoline-powered engines, the pesticides, herbicides and chemical fertilizers, and the monoculture look. But growing numbers of people see that approach as poorly adapted to the west, and at odds with the healthy functioning of the earth. Approximately half the water used by each household is for the landscape, and it is estimated that 75% of outdoor water use goes to watering lawns. This is both because turfgrass covers most of the ground in most landscapes, and because bluegrass has a high water requirement. And with the rising human population, with the trend to higher temperatures, and because of the polluting of our water supplies, water is becoming more and more scarce, and is fast becoming “the new oil”.
So how do we cover the ground so it looks good to the neighbors and to us, but is thrifty on water use, energy, money and maintenance; and is environmentally friendly. Unfortunately a genuine answer may be years in coming. For now, two possible solutions are in the right direction: change how we maintain our turfgrass by giving it less water etc, put turf only where it performs well, and use turf only where a lawn is really wanted; and we could also replace bluegrass with groundcovers that require less water, pesticides, fertilizers and maintenance.
Lawn grasses, and especially the aggressively spreading bluegrass, have an unsurpassed value as a groundcover in high traffic areas like sports fields, parks and play areas for children. They hold up well to wear and they can repair themselves quickly. And besides absorbing greenhouse gasses, lawns can create a cool and restful quality in a landscape. And some people really identify with lawns. Wasn’t it Greta Garbo who said, “I vant to be a lawn!”? People should be able to enjoy their landscapes, and I do not support covenants that prevent lawns any more than I support covenants that require lawns.
However lawns have more problems than just the high-water needs of bluegrass. It is estimated that seven million birds are killed annually by lawn-care products. And this statistic only represents one example of the negative environmental impact of lawns. Current lawn-care practices are polluting our water supply, poisoning our streams and killing off the earthworms, beneficial bacteria and fungi that build our soils and support our plants. And by killing off nature’s beneficial insects, lawn pest controls create more pest problems. Chemicals applied to turf is tracked inside to carpets where crawling children are exposed to them. Lawns are also responsible for the emissions of thousands of gasoline-powered mowers and blowers. And lawns are not cheap; the United States spends $40 billion a year on lawn care.
Lawns have many other problems. They are monocultures so they do not cultivate a natural balance and instead promote pest infestations. They are watered inefficiently; approximately one third of the water used to irrigate lawns never gets to the lawn. And lawns are often put down in areas where they are really not appropriate. Curtis Manning of Manning Design identifies seven such areas: 1) residential front yards (because they are rarely used to play on and shrub borders and perennial beds could provide more beauty with less water). 2) residential yards with big dogs (because no grass can stand up to dog traffic and organic mulch works much better where dogs run). 3) hell strips between the sidewalk and street or building (because they are too narrow to water efficiently and because many other plants are more successful) 4) Slopes (because they are difficult to water and mow and because ornamental grasses or groundcovers are better). 5) medians and roadsides (because they are difficult to water efficiently and often too hot for turfgrass. 6) Commercial sites (because they are only walked on by the weekly maintenance crews and because the turf could be replaced by plants requiring much less water. And 7) Industrial sites (because they have the same problems as commercial sites. Of course these statements refer to Colorado. In Kentucky, bluegrass might be the best-adapted groundcover.
Now even though I am making a strong case against the unquestioning use of bluegrass lawns, I am neither trying to bash grasses, nor to discourage the use of grasses in the landscape. There are numerous native ecosystems where grasses play an important role, like in prairies and meadows. If we use grasses that are well-adapted to Colorado and if we can grow them in an ecological way, then I would not be upset if grasses should get more than 50% of the landscape area. From an eco-system perspective, I support whatever will make the most sustainable environment with the best balance of plants, insects, fungi, soil bacteria and humans.
In the last 20 years and especially in the last 10 years, many new developments and pressures have been urging us to change how we do landscaping. Water conservation has gone from a fad to a mandate, and maintenance costs are increasing with fuel prices. Added to these are the more positive pressures of increased public interest in plants and the green industry response to breed, select and propagate hundreds of varieties that were previously unheard of or unavailable to the general public. Also, 50 years of pesticide and herbicide use has not only proved their poisoning effects on us humans, but they have also been shown to be very inefficient in terms of long term pest control. Pests have become immune to many pesticides, pesticides kill the beneficial insects thus increasing the need for more pesticides, and pesticides kill the soil life which makes plants weaker and more vulnerable to pests.
These pressures and changes have brought about trends toward more diversified, more colorful, more naturalistic and more sustainable landscapes. And these trends are driving a search for alternatives to the monotonous perfectionism of the bluegrass lawn.
One idea to “de-fetishize” American lawns is called the “Freedom Lawn”. It is a lawn made by simply mowing whatever comes up: bluegrass, ryegrass, fescue, dandelions, clover, plantain, crabgrass, bindweed, etc. Another idea proposed by Frank Rossi of Cornell University and also by the University of Minnesota Extension Service is called the “Low Input Lawn.” This lawn is made from whatever lawn you already have, using less fertilizer and herbicides, less frequent watering and increasing the mowing height. To these I would add, letting the lawn go dormant in the summer. Bluegrass cultivars could be selected for more drought tolerance and for the ability to go into and out of dormancy with little or no loss of coverage. We saw this potential in 2002 when some bluegrass lawns turned brown during water restrictions and then came back perfectly green when they were watered again in the fall. A simple change in our attitude to accept the look of brown lawns in summer, would save acre-feet of water, much needless frustration, significant maintenance costs and our valuable summer time. We could do this and still keep an area of green grass in the backyard for the kids to play on, or keep the front lawn green and let the back lawn go dormant. Tony Koski at CSU has spoken eloquently on the ability of bluegrass to come back from dormancy and Dorothy Borland has great photos of bluegrass that had been unwatered because of special events, turned brown, and then came out of dormancy looking completely recovered.
Then there are the new “Ecology Lawn Seed Mixes” which are intended to produce lawns that are low-maintenance, low-water use and low fertilizer-requiring. One commercial formula is called “Fleur de Lawn” with short grasses and wildflowers. Surely CSU, Pawnee Buttes Seed Company or somebody could come up with a good “Ecology Seed Mix” for the Rocky Mt. West.
. Here’s another idea: call that landscape in the front yard a “meadow” instead of a lawn, and plant it with all sorts of things. With a new name and much diversity, blemishes and bare spots would be far less noticeable than in a uniform lawn. For this approach, I would suggest choosing a matrix mulch of organic matter or very fine gravel like squeegee that could be used around the plants. Then, if you keep a bucket of this material handy, if a plant dies or that dreaded bare ground appears, grab your bucket and splash a little mulch here and there until you have time to replant.
Besides bluegrass, there are other turfgrass alternatives. Buffalograss, blue grama and dwarf tall fescue all have their pluses and their minuses. To my understanding, they all have significant problems, but I will leave it to someone more knowledgeable to discuss this subject.
And the search is on for plant alternatives to turfgrass for covering the ground. For the past five years, I have been testing 68 different groundcovers that need only half or a quarter of the water required by bluegrass.(assuming that is 25”-30” of annual irrigation). Many seem good alternatives to turf where there is no traffic, especially in areas where lawns are not doing well. And Cornell University recently completed an evaluation of 15 herbaceous perennial groundcovers. They concluded “In comparison to the most common landscape groundcover—a mixed turfgrass sod—herbaceous perennials can provide reduced maintenance opportunities and a greater aesthetic appeal.”
Non-grass groundcovers have many values in the landscape. They can be used as a living mulch around taller perennials and shrubs to hold down soil temperatures, decrease drying out of the soil, lessen the growth of weeds, and can act as companion plants by providing nectar and habitat for beneficial insects. Not only do many of them need less water than bluegrass, they can be watered with drip irrigation which is 90% efficient compared to conventional spray heads with 60%-70% efficiency.
Of course there are aesthetic reasons to use groundcovers. They provide flower color and sometimes foliage color. They have a wide variety of textures and can be used to create beautiful edging along a walkway, path or driveway; to make a transition between a lawn and perennials and shrubs; and to create a layering effect in the front of a perennial border. They can look great spilling over walls or squeezing between rocks.
Another important consideration is the mutual competition between grasses and trees. Trees create shade which most grasses don’t like and grasses have dense root systems which take away water and nutrients from trees, and are especially detrimental to young trees. Some grasses, including Kentucky Bluegrass, release chemicals into the soil which suppress the growth of tree roots. Our communities need trees for many reasons, especially if the trend of increasing temperatures continues. Therefore it is wise to put trees, especially new trees, in islands separate from grasses. These tree islands are good places to use low-water groundcovers. Their root systems are less aggressive than grasses and they can be selected for shade tolerance. In addition they can add color to the areas around trees. Use of groundcovers rather than turf can also save the trees from being damaged by lawn mowers, string trimmers and herbicides.
More reliance on xeric groundcovers would not only reduce our water use as a community, but in cities like Boulder with Water-Budgeting programs, homeowners who have replaced some turf areas with xeric groundcovers would have more water in their budget to use for watering and keeping alive trees. Trees and shade can make vital differences in our lives if temperatures are increasing. And trees are very vulnerable to drought.
However groundcovers, like turfgrasses, have their limitations and need to be used appropriately. Just because groundcovers are perennials doesn’t mean they are immortal, and so periodic replacements will be necessary. Even in those parts of the landscape where flowering groundcovers would be better choices than turfgrass, large scale and significant changes away from the traditional lawn will not be simple. Technologies and methods for cultivating lawns have developed over the last 50 years and there will need to be new technologies and developments for maintaining groundcovers and perennials in an economical way.
If we change our landscape ideal from an unnatural and unrealistic monoculture to a sustainable and diverse imitation or re-creation of nature, then we will have to accept a more naturalistic idea of perfection. This approach would not only save a lot of water, it could save our entire landscape if water becomes severely restricted. This more sustainable landscape could still be beautiful to look at and an enjoyable environment to be in. It could both reflect and support our natural Colorado ecology.