February 2007 garden planner

Think about cover-ups

Check out the garden for large bare-soil areas that would benefit from ground-cover plantings. Areas with chronic weed problems or where existing ground cover is struggling are candidates. Note the soil, light and weeds that are present, and then look through garden publications for plants that match the growing conditions.

Aside from standard ground covers, some hardy low-growing shrubs may fill the bill: Russian cypress (Microbiota decussata), dwarf Japanese spirea (Spiraea japonica 'Nana'), prostrate junipers, Rhododendron 'Ruby Hart,' Stephanandra incisa 'Crispa' or ground-cover roses.

In USDA Zones 4-6, wait to plant until soil warms up, but in Zones 7-9, planting of woody ground covers can begin during winter when temperatures are in the 40s, as long as the soil is not too wet. For herbaceous plants, start in early spring, or plant throughout the growing season as long as you provide mulch and water.

SOURCE: "Month-By-Month Gardening in Washington & Oregon," by Mary Robson

PLANT NEW GROUND COVER

The number of plants you need for a ground cover depends on the size of plants (flats, 4-6 inch pots, 1-gallon or No. 1 containers), growth habit and growth rate. Here's how to plan for a new area.

1. Prepare the area by removing weeds and mulching thickly with 4 inches of coarse organic material. This can be done weeks to several months before planting.

2. Measure the area. Then calculate the number of plants to fill it at the desired spacing. One hundred plants such as Ajuga or strawberry set 8 inches apart should cover about 44 square feet. A spacing of 18 inches for woody plants such as 1-gallon cotoneaster covers 225 square feet.

3. Use a triangular grid to provide equal spacing in all directions. Make a template of cardboard or bamboo stakes for large areas. Plan to add filler plants in the second year.

4. Plant through existing mulch by scooping away enough to expose a bare patch for each spot. Water in if needed.

5. Water smaller plants more frequently than larger transplants. Fertilize lightly during the first year or two. Weed new plantings three to four times a month during the first growing season. The frequency will slow as plants fill in.

SOURCE: "Month-By-Month Gardening in Washington & Oregon," by Mary Robson

TEXT: Diana K. Colvin

PHOTOS: Marv Bondarowicz/The Oregonian

AROUND THE STATE

This is a good month to get a soil test.

In Western Oregon, plant inside seed flats of cabbage, cauliflower, broccoli, brussels sprouts.

Plant early-spring greens later in the month when soil temperatures range from 50 to 60 degrees.

Plant onions outdoors as soon as the soil is dry enough to dig.

Plant new roses; prune established ones. Also, plant fruit trees and deciduous shrubs.

Prune deciduous summer-blooming shrubs and trees. Also, prune fruit trees and blueberries.

Prune and train grapes; prune and trellis trailing berries.

Prune clematis and other ornamental vines.

If weather permits and soil is dry enough, spade or till garden areas for planting later.

Fertilize rhubarb with well-aged manure or a complete fertilizer.

Stay on slug and weed patrol.

In Central and Eastern Oregon, plant asparagus crowns if the soil is diggable.

Cut branches of quince, forsythia and flowering cherry and bring inside to force early bloom.

SOURCES: Oregon State University Extension Service, Seattle Tilth's The Maritime Northwest Garden Guide