New to Gardening in Western Washington? – Tip Sheet #3

Get acquainted with your landscape. Make a sketch of the yard and label all the plants you can identify. If you can, ask the seller about plants you don’t recognize. Note which areas get sun or shade. To help you remember plants in the future, set up a folder labeled “plant tags.” As you buy plants, just put the tag that describes them into the folder. You may not want to make major changes the first year. Instead, update your sketch as the seasons change. You may find plants emerging that you didn’t know were there.

If you plan to dig more than 12 inches underground, Washington law requires you to have utility lines located and marked so they won’t be damaged. Call 811 two business days before you dig. Once utility lines are located (a free service), mark them on the landscape sketch you made.

Stay “In the Zone” The U.S. Department of Agriculture divides the country into hardiness zones based on average lowest winter temperature. Most of King County is Zone 8 (10-20° F), but the eastern part is Zone 7 (0-10° F) or Zone 6 (-10 to 0° F). If you are not sure of your zone, ask a nearby nursery or Master Gardener clinic. Nursery plant labels will usually indicate zone hardiness. You can go lower than the zone you are in but you should not go higher. For example, if you are in zone 8 you can use plants labeled for zone 7 or below. Plants that thrive in the higher zones are not cold-hardy and will not survive our winters.

Throughout Western Washington, varied topography gives rise to many microclimates — areas where local conditions may differ from those of the surrounding climate zone. WSU publication FS181E, “How to Determine Your Garden Microclimate,” is available free at pubs.extension.wsu.edu and can help gardeners understand their unique growing conditions.

Plant labels will also indicate the plant’s light requirements.

• Sun: at least 5 to 6 hours of direct sunlight each day during the growing season
• Partial shade: 2 to 4 hours of sun a day
• Shade: only filtered light for the entire day

Sun-loving plants may survive in shade but won’t prosper or bloom well. Shade-loving plants in sun will probably sunburn and may die.

For a more detailed glossary of sun, shade and other gardening terms, see Great Plant Picks website: www.greatplantpicks.org/resources/glossary. The Great Plant Picks site is also an excellent for source for plant recommendations that do well in the Pacific Northwest.

Choosing plants that become too large for their location is a common gardening mistake. Don’t think about the size of the plant now; consider its full-grown size. The plant tag should tell you the expected height and width of the mature plant. The Sunset Western Garden Book is a good reference for plant descriptions, including size and cultural requirements.

Even though we have a long growing season, the weather is relatively cool, so you may not be able to grow some of the vegetables that thrive in hotter parts of the country. For example, tomatoes can be successfully grown here, but short-season varieties should be selected. Vegetable varieties listed in the Territorial Seed catalog, www.territorialseed.com, can reliably grow here; you needn’t buy from them. Local nurseries generally stock seed and starts that do well here.

Landscape planting can be done in spring or fall. Dig a hole no deeper than the root mass and at least twice as wide. Remove any burlap and tying materials and loosen the roots. You want the roots to spread into native soil, so don’t add any fertilizers, organic matter or other amendments. Place the plant so that the base of the stem or trunk is slightly above the soil surface. Unless the site is windy, don’t stake plants. If you do use stakes, be sure to remove them after one growing season. For more planting advice, see WSU publication FS047E, “Planting Trees and Shrubs in the Landscape,” available at pubs.extension.wsu.edu.

Despite its rainy reputation, the Puget Sound area typically gets only 3 to 4 inches of rain for the entire summer. Some plants in your garden need an inch of water a week or more during this time.

The objective of good irrigation is to apply water carefully and slowly so that it wets the entire root zone. Quick, light sprinkling will not do the job. Frequent, shallow watering leads to shallow roots, and shallow roots lead to more rapid stress under dry or hot conditions. Water less frequently: once or twice a week but deeper. Take a trowel and dig down several inches and see whether water has penetrated to that level. Try to avoid watering from above the plant: Getting water on the leaves can encourage fungal diseases.

Consider adding mulch to your landscape. Mulch will help retain moisture, control weeds and contribute to healthy soil. WSU recommends arborist wood chips. See WSU publication FS160E, “Using Arborist Wood Chips as Landscape Mulch”, available at pubs.extension.wsu.edu, for more information.

Many people set their mowers too low and cut the grass too short. Set your mower so that it cuts the grass no shorter than 2 to 3 inches. Don’t remove more than one-third of the grass leaf at any one cutting. That will encourage deeper, healthier roots, help retain moisture, and help the grass compete with weeds.

Leave clippings on the lawn; they will quickly decompose and add nutrients back into the soil. Consider using a mulching mower to chop up grass clippings before depositing them on the lawn. Contrary to common belief, grass clippings do not cause a buildup of thatch. Avoid weed & feed fertilizers.