LAWN CARE IN THE PACIFIC NORTHWEST Laying the Groundwork for Healthy Grass West of the Cascades The Pacific Northwest and, in fact, the entire western Cascade region running from Central British Columbia, through Washington and Oregon and down into Northern California is blessed with a mild climate and abundant rainfall. This is great for growing lush perennial gardens, but the continual rain and the dense shade from native conifer trees make it hard to establish a new lawn. It can be done, though. By carefully preparing the soil, choosing the right type of grass, and planting the lawn at the appropriate time, you can make sure it’s your side of the fence where the grass is greener. Planning the Pacific Northwest lawn When choosing which grass species to plant, consider how you’ll use the lawn. You’ll need a more rugged variety of grass to stand up to ballgames and picnics than if you’re only planting a lawn for looks. Also, take a look at the shape of the area where you want to establish the lawn. Especially in the rainy Northwest, lawns should have a slight slope away from buildings or sidewalks to let excess water run off. A slope of anywhere from 1% to 6% is ideal. If you’re planting in a hilly Seattle neighborhood, though, keep in mind that while a slope of up to 12% is acceptable, any steeper and you’ll have problems with mowing and watering. For steep slopes, you can either regrade or opt for a hardy native ground cover like slender wintergreen (Gaultheria ovatifolia) or inside-out flower (Vancouveria hexandra) instead of lawn grass. While the lawn area might slope, the surface itself should be even. If there are low spots where rainwater could puddle, even them out before you plant. Soil types west of the Cascades Most lawn grasses prefer sandy loam soils that let water reach 8 to 12 inches into the soil. The silty loam soils of this region are also adequate for lawns, though. The black clay found in Oregon impedes drainage, but adding compost can take care of this problem. If you’re higher up in the Cascades, you may be dealing with decomposed granite, in which case you’ll have to add a considerable amount of organic material like topsoil and compost before much of anything will grow. Partly due to heavy rainfall leaching the soil, high pH (acidic) soils are common in the Pacific Northwest. Acidic soils aren’t the best for lawn grass and they also encourage moss and lichen, which are always ready to invade Cascade-area lawns. To find out if you’ll need to amend to soil to lower the pH or add minerals such as calcium, magnesium, potassium or phosphorus, have a soil test done by a local nursery or conduct one yourself using one of the kits available at gardening centers. Type of grass for the Pacific Northwest Most of the Pacific Northwest/Cascade region falls into USDA climate zones 8 and 9, with zone 7 starting in the Cascade foothills and zone 6 occurring higher up. The turfgrass map also used by some landscapers places the Pacific Northwest in the cool/humid zone. For these zones, the best choices are fine fescues like red fescue (Festuca rubra), along with certain bluegrasses and ryegrasses. Bentgrasses also grow well in the Northwest, but they require plenty of sun and regular maintenance. If you live near the coast, try “dwarf” tall fescues. Theses will need to be allowed to grow higher, but they offer a deep green color and tolerate salt better than most species. Buffalo grasses and zoysia grasses can also be grown in the Northwest, but they do better in the warm climates of southern Oregon and northern California. For warm microclimates, Bermuda grass is another possible choice. As a rule, if you want to use your lawn for sports, choose rye; if it’s just for show, go with fescue. Fescues do well in sun, but still keep a healthy green color in the shady areas. Most ryegrasses need full sun to thrive, but they stand up to foot traffic better than fescues. In most cases, the ideal will be fine fescues such as creeping red or chewings mixed with ryegrass. The rye is useful because it sprouts quickly and offers coverage to prevent weed growth. Be aware of shady spots where obstacles like trees or brush block sunlight. Shade can hinder your lawn's ability to rebound from stress or fight off disease and pests. Shaded grasses also retain water. If you have a deeply shaded area of lawn, trim back the low-hanging limbs of shade trees to enable light to filter through. You can do this without greatly compromising the shade you like to have in summer heat. Rake up clippings and snapped branches that can further block your lawn from the sun. If all else fails, consider reshaping your lawn area and plant shade-tolerant shrubs, flowerbeds, or ground cover. Don’t forget about native grasses, either. Because natives are adapted to local conditions, when planted in an appropriate site, they don’t need nearly as much watering or fertilizing as “imports.” Grasses native to the western Cascade region include Oregon bentgrass (Agrostis oregonesis), western fescue (Festuca occidentalis) and creeping red fescue (Festuca rubra), blue wildrye (Elymus glaucus), Alaska oniongrass (Melica subulata), and Columbia sedge (Carex aperta). One grass to avoid in the Pacific Northwest is Kentucky bluegrass (Poa pratensis). Although popular in the north, most areas of the Northwest are too wet for this prairie grass. It does sprout quickly, though, so having a small amount in the seed mix will provide temporary coverage before the rest of the grass comes in. Seed or sod? Sod may seem like an easy route to an “instant lawn,” but for the long term, seed is a better choice. The roots of sod grass are likely to have been damaged by drying or contact with rough surfaces and this will affect the long-term health of the lawn. Another consideration for Northwest lawns is that most sod is primarily rye and Kentucky bluegrass, neither of which does well in this area. Sod is usually more expensive than seed and it’s more labor-intensive to plant than seed. For the healthiest lawn and fewer maintenance problems down the road, invest in the best, certified-quality seed you can find. Pacific Northwest lawn planting times West of the Cascades, spring is not a bad time to plant grass, but early autumn from late August through mid-October is better. If you’re at a higher altitude or planting fine fescues, try to get the seeding done in September. The reason for autumn planting is that there are fewer weed seeds waiting to sprout and the cooler temperatures make it easier to keep the new lawn moist. If your area receives frost, the grass will die, but the lawn will return again in spring. Early spring from April to mid-May is also a good time to seed, provided you can keep the lawn well watered when the weather heats up. A new lawn should be kept moist for the first two months, so in particularly hot spring you may need to mist or water lightly every morning and late afternoon. As the nationally famous gardens of Seattle and Vancouver, B.C. show, it is possible to establish a thick, green lawn west of the Cascades. If you’re planning to grow a lawn in the Pacific Northwest, check your soil type and amend as needed, choose a species of grass that’s appropriate for the climate, and you’ve already done half the work to ensuring a beautiful lawn for your home’s landscape. Seasonal Lawn Care in the Pacific Northwest Spring Get your mower ready: Make sure your lawn mower is ready before you need to use it. Bringing it in before the start of the season will ensure you won't have to wait along with everyone else in your neighborhood. Note: Don't overlook sharpening your mower's blade. For the cleanest cuts -- and healthiest-looking lawn -- sharpen the blade at least once a year. Start a new lawn from seed: Fall is the best time to sow seed for a new lawn. If you can't get to it at the end of season, spring is the next best time. Don't wait too long; your lawn needs to get established before summer arrives. Prevent crabgrass from being a problem: Annual weeds, such as crabgrass, grow from seed each spring. Use a well-timed application of pre-emergence herbicide to stop them from growing at all. A good guideline is to spread the pre-emergence herbicide as forsythia blooms in your area start to drop. Corrective measures to fight moss: Moss may seem inevitable in the Northwest, but it really can't compete for air, water, and nutrients in a healthy lawn. That's why you'll find it growing in bare spots of your lawn where the grass has been stress damaged or depleted of sunshine from overhanging tree branches. It also occurs where the lawn is overly compacted, too acidic, or has poor overall drainage. If you already have rampant moss growth, February is a good time to apply a moss killer. Brands vary, but the most effective contain iron (ferrous ammonium sulfate, ferrous sulfate, or ferric sulfate) and potassium salt. Follow directions carefully, as the iron can stain sidewalks and driveways. Recommended ranges are from 0.5 - 1.5 pounds of iron for each 1,000 feet of lawn. When you're done treating for moss, you should over-seed the bare areas to eliminate future moss habitat. Ryegrass (or fescue) is a solid choice. Check soil pH: Checking soil pH is important. In the Pacific Northwest, lawns love a soil pH between 6.0 and 7.0. If your soil is too acidic, apply lime. It's wise to consult your local university extension or lawn care service to determine the right amount of lime for your local soils. Aerate compacted soil: Most lawns have trouble growing in compacted soil (many weeds, unfortunately, thrive in it). Aeration increases drainage, eliminating pools where moss can cultivate and thrive. If you need to or want to aerate, do so in spring -- when your grass is actively growing. Rent a power aerator for best results, or hire a professional. (Note: these are large power tools that can be challenging to operate.) The soil should be moist, and making two or more passes gives better results. The aerator pulls up soil cores onto the lawn. Rake or mow to break up the cores. The soil cores will help decompose thatch layers in the lawn. If your soil is deeply compacted (more than 2 inches-dig a hole to find out) find a landscape professional who has equipment that penetrates 6 to 8 inches to aerate for you. Begin mowing: Allow your grass to grow no more than 3 inches tall before you start mowing. The best general rule to follow is that you want to keep most grass types at least 2 inches tall -- this height helps the grass ward off weeds and withstand summer drought. But you don't want to remove more than a third of the total grass height at any one mowing. Removing too much stresses the grass. Apply fertilizer: If you feed your lawn a couple times a year, a light application of lawn fertilizer in spring helps get your grass off to a great start. Wait to fertilize until your lawn needs mowing for the first time. Do a light application and use a slow-release or organic fertilizer; don't try to feed your lawn for a quick green-up; this doesn't usually work and can harm your grass. Summer Attack grubs: If lawn grubs are an issue in your lawn, prevent further damage by applying grub-control product that continues to work throughout the season. The best time to do this is in early June. Mow as needed: Because most grasses in this region like it cool, they won't grow as fast when temperatures go over 80 degrees F. During hot, dry periods, it may only need mowing once every two or three weeks (wait for it to grow about 3 inches tall). In cooler, moister weather patterns, mow enough to keep it from getting more than 3 inches tall -- that could be every week or more than once a week. Water wisely: Allow your grass to take a summer nap during hot, dry weather if you don't mind it turning brown. When the rains come again, it'll go green and start growing again. If you don't like the look of a brown lawn, select drought-tolerant types such as buffalograss or plan on giving your lawn about 1 inch of water a week. Fall Fall feedings: If you only fertilize your lawn once a year, autumn is the best time to do it. In fact, your lawn would appreciate a light application of fertilizer in early fall and again in late fall. Aerate: If you didn't aerate in spring and your lawn needs it, fall is a great time. Don't overlook the importance of aerating. It'll help your lawn thrive. Continue mowing: As temperatures cool, your lawn will grow faster again. Keep mowing regularly through the end of the season. Fall cleanup: Clean up fallen leaves. If you don't want to spend time raking them, run your lawn mower over your lawn two or three times. This will chop the leaves into fine pieces; they quickly decompose and add to your soil's structure. Or rake up and compost the fallen leaves. Dethatch when necessary: A 1/2-inch thatch layer can be beneficial, but much more than that can keep water, air and fertilizer from reaching the roots. Too much dead grass residue prevents proper drainage. Rent a power dethatcher and make several passes. This tool rakes up large quantities of grass to pull up the thatch. Rake up the thatch and compost it after dethatching. Then overseed to thicken the lawn and crowd out weeds. Overseed your lawn: Most Pacific Northwest lawns will have cool-season grasses, so autumn the best time to overseed or grow a new lawn from scratch. Overseed, after raking or aerating to expose soil, with a perennial rye/fine fescue mix designed for Pacific Northwest conditions. Talk to a knowledgeable nursery-person for seed recommendations. A light application of "starter" fertilizer can help the seeds grow quickly and crowd out weeds. Plan carefully; your new grass needs at least a month before your first average first frost so it can get established. Attack perennial weeds: Most perennial lawn weeds, such as dandelions and ground ivy, are most susceptible to attack in fall. Treat them with a broadleaf herbicide (there are chemical and organic choices available) or pull them by hand. General Year ‘round Problems with shaded lawns: It's rare to find an American lawn that gets no shade from trees or overhanging eaves. That means that the grass species on your lawn may not fare well in spots once your shade trees have matured. Depending on where you live in the country, there are warm-season and cool-season grasses that simply have a higher shade tolerance than others. You'll know if you have a shade-tolerance problem if your lawn has inconsistent or weakened qualities where obstacles like trees or brush block sunlight. It's a good idea to let shaded areas grow taller before mowing--say, up to three inches--and to water deep into the lawn less frequently in shaded than in sunny sections. Continue to trim back the low-hanging limbs of shade trees and thin them to enable light to filter through. Getting Rid of Gophers and Moles When vegetation and plant life begin to disappear from lawns or backyards, there may exist a problem. That problem is what is known as the pesky gopher, or the pesky mole. The gopher is an animal that will by its very existence wreck havoc beneath lawns and backyards. These animals of the rodent family live and feed below the surface of the ground, eating the roots and tubers of plants, and effectively killing these plants. These solitary silent animals, as they busily tunnel their small furry bodies below the surface of lawns, gardens, and golf courses, severing grass roots, leave behind a trail of subtle destruction that is demonstrated by their telltale mounds. This can produce not only a bit of frustration but also a sense of helplessness. First, you may want to determine whether it is gophers or moles that are demolishing the underpinnings of your plants and lawns. Below are illustrations of the differences between moles hills and gopher mounds. If the holes popping up in your yard are more fan shaped than volcano shaped, you’ve probably got a gopher under your lawn. Controlling unwelcome gophers and moles can be accomplished in several ways. The method you select will depend on the degree of infestation, your aversion to toxic chemicals or your willingness to dig long, deep trenches. Placing a poisonous substance into their tunnels Poisonous pellets should definitely not be a method implemented or even considered if there are children and domestic animals around, as this would then present a serious life threatening danger to them. The most common rodenticide on the market is strychnine-laced barley. It is sold at hardware stores or garden supply stores, but permits are sometimes required if you intend to purchase a lot of it. The application procedure involves jamming a sharp, hollow pipe (like a syringe) into the gopher’s tunnel, and dropping a few seeds through the pipe. Then covering the small hole you’ve made. Then, you wait. You may not know if you’ve killed the gopher for several days because unless they make new mounds, how do you know they’re alive? This is the problem with using poison to get rid of pocket gophers. Fumigation Debate surrounding the effectiveness of fumigation to get rid of pocket gophers is on-going, but it is still used by many pest control professionals. These are hazardous, dangerous chemicals and some thought should be given before deciding upon this option. Use a shovel or spade to open the burrow, and clear debris. Put a pipe large enough to pour aluminum pellets through into the burrow, deep enough that the pellets reach the gopher’s runway. Then, cover the entrance to the burrow with dirt and pack it tightly to ensure that gases do not easily escape. You may want to plug the hole first with a ball of newspaper to prevent burying the pellets, thus preventing the gas from releasing properly. Do this until you run out of aluminum phosphide pellets. This procedure is often done by a professional, so you should talk to your local conservation officer or wildlife management specialist before considering fumigation. Trapping the pesky creatures This is a safer method, although it will not completely eliminate the problem, it is a means of controlling the population that may exist in any particular area. Deciding to use this method one only need to be vigilant while performing this type of pest control, which should be done on an ongoing basis. Also, common sense and good judgement is required here as to the type of trap one is going to use, as some traps are safer if children and domestic animals do get into them. One of the more unsafe ones is the harpoon trap, which has sharp elements. The pit traps are probably the safest as they are comprised of a can that is approximately seven inches wide and twelve inches deep. Here there are no sharp edges that can harm a child or an unsuspecting animal besides the gopher. First, you’ll want to find the main runways extending out from the burrow. Main burrows usually have two tunnels heading in opposite directions, and you can usually guess where those tunnels are by drawing a line from the burrow hole to the outermost edge of the debris kicked up by the gopher. Here is a diagram of what we’re talking about: Now, you may need to poke around a bit with a metal pole to find the tunnels. You’ll know you’ve found a gopher tunnel once the pole feels like it’s broken through something and dropped roughly 2-3 inches. Do this on both sides, as the diagram shows you. Now, mark those spots and get a shovel or a post-hole digger. Dig a hole just deep enough so that you can see the bottom of the gopher’s runway. You’ll want to clear any debris so that you can set your traps in on both sides of the tunnel. Once the traps (most traps have the same directions and function in much the same way, but make sure to wash your scent off of them before you put them in the gopher hole) are set, you will want to tie a piece of twine to each trap and tie that twine to a post driven into the ground above. Now, cover the hole you’ve made with a board larger than the hole. Then cover the edges of that board with dirty to prevent any light from seeping through. Gophers will quickly abandon a tunnel if they see any light. Check the traps every other day. If you don’t catch any gophers within 3-4 days, find another burrow and repeat the process until you do. Fencing in a particular area or even an entire yard This is an effective but labor intensive method for getting rid of gophers. Since gophers feed on certain plants and plant structures like tubers, roots, and other vegetation, it’s often times enough to simply exclude the gophers from a particular area—like your garden, for instance. Digging a trench 2 feet deep around the perimeter of your garden and lining it with 1-1/2” galvanized hardware cloth or chicken wire should provide a fence deep enough to keep gophers out. You must also make sure the fence is no less than a foot off the ground to prevent gophers from climbing over it. But, gophers have been known to burrow as deep as six feet, so the reliability of exclusionary tactics to get rid of gophers does deserve some scrutiny. Flooding This is perhaps the next least toxic way to get rid of gophers, though it may not be so complete in ridding yourself of the population for long. This is done in much the same way it is done to get rid of moles. Dig a hole deep enough into the burrow to expose the gopher’s main runway—make sure you bring a big shovel (you’ll know why in a moment). Then, insert a garden hose into the hole and turn the water on. Allow the water to run for no less than 15 minutes, or even longer; gophers have been known to work within tunnel systems more than 1200 square feet, so it might take a while to flood. While you’re waiting, keep an eye on the other burrows. If you see the gopher trying to escape, run over there and give him a good whack with the shovel. That should solve your gopher problem. Alternative Methods of Gopher Control The roots of the oleander plant are known through anecdotal evidence to be a repellent of gophers. Many people who believe in the oleander trick will line the perimeter of their garden with oleander plants in the hopes that burrowing gophers will not cross that line. How effective this is, I don’t know. I imagine there is a chemical in oleander root that is diffused into the soil that is unpleasant for gophers, if in fact this strategy actually works. Crop rotation is a great trick for farmers or people who grow vegetables in large quantities. It is often suggested that people who grow alfalfa should rotate their crops with grains like wheat to deprive any gophers that have moved in of food. Question though: won’t the gophers just follow the crop rotation? That depends on how far apart the two crops are. Longer distances means gophers are less likely to travel above ground, let alone burrow, that far. Carbon Monoxide fumigation is one of those tricks the professionals will tell you not to try because it’s dangerous. The reality is, carbon monoxide is only dangerous in confined spaces and the only thing found in a confined space for this procedure is the gopher. Get some exhaust piping or hose (found in automotive parts stores) and attach it to a lawnmower or your car’s exhaust pipe. Go around and make sure all of the gopher mounds are packed tight with a shovel. Then insert the hose into an open mound hole and let the engine run for a good 15-20 minutes; this should be enough time to suffocate the gopher. Sometimes a gopher will try to escape, which is why you always bring a big shovel with to play a game of whack-a-gopher. Castor Oil is another known method that is used. Here a mixture comprised of a few ounces of castor oil and several tablespoons of liquid dishwashing detergent, which is then added to a gallon of water. For the more determined, the addition of human urine, and then spraying this concoction over the lawn area where the gophers or moles are suspected. What is hoped is that the unsuspecting creature will ingest this substance, and incur a tummy ache (indigestion), then perhaps have the good sense to move on to more pleasant surroundings, hopefully someone else’s lawn or garden. The plus factor in using this method is that it is nontoxic to the environment, and presents no harmful elements to children or domestic animals. Gophers and moles unfortunately will continue to present a problem for lawns and gardens, but with persistence and a certain amount of patience as well as perseverance, these destructive pesky creatures can be controlled. On the other hand by doing nothing at all won’t be the end of the world, as we know it. Or in this case the lawn or garden as these creatures do help keep the insect population down as well as providing a means of aerating the soil by their tunneling. A note from one of our DaVincisWorld denizens: - "Some years ago, I discovered, by accident, that broken glass is a serious deterant to gophers and moles. In the yard of a 100-year-old home, I planted a garden in an area untouched yet surrounded by gopher activity. The one difference between this and the surrounding soil was the presence of an occational piece of broken glass. As it turns out, it was an the old household dump site where garbage was buried before the days of garbage service or municipal dumps. Subsequently, I have placed crushed glass under root balls upon planting and forced glass down gopher holes in lawns with great success.