Monday, December 8, 2008
Real Curb Appeal
This is one of my favorite native plants for shade, Mahonia nervosa (Low Oregon Grape)
Front yards can be pretty small in most urban-size gardens, and the area between the street curb and sidewalk (called the parking or planting strip) is sometimes the biggest space for a front garden. Yet these strips can possess several difficult characteristics: they're usually far from a water spigot, have poor soil, and are in full sun with reflected heat from the surrounding pavement.
However, all these obstacles can be overcome! Improving the health of the soil, choosing the right plants, and shading out weeds with densely planted shrubs and groundcovers can create real curb appeal for your home and garden. (not to be confused with the overplanting techniques in the HGTV show of the same name, which result in a "maintenance migraine" and plant decline)
Sunny planting strips can be used as a combination herb-and-ornamental-garden by planting Lavender, Rosemary, Yarrow, Verbena, or Salvia (Sage), mixed with Cistus (Rockrose) and Sedums of any kind. These plants are all quick to establish and grow, and provide flowers from spring to fall. They'll all need to be watered during their first 1-2 summers, but then will thrive with only what Mother Nature delivers.
For part-to-full shade strips, Mahonia nervosa or M. repens (Low Oregon Grape), Sarcococca ruscifolia (Sweet Box) and all species of Epimedium (Barrenwort) species are hardy evergreens that provide a cool and peaceful look, and fragrant flowers from January to May.
Trees are a great focal point in a planting strip, and will provide shade for their own roots and the plantings beneath, which will reduce water needs for all. In choosing a tree, first look at what may already be in the planting strips on your street. Continuing a theme that's already present can have a unifying effect for the block.
For small planting strips, Magnolia grandiflora 'Little Gem" provides fragrant summer flowers, grows only 15ft. tall x 10ft. wide, and makes a nice evergreen screen. For larger planting strips, Gingko biloba (Maidenhair Tree) Parrotia persica (Ironwood) and Acer griseum (Paperbark Maple) are in the 25ft x 20ft range with gorgeous fall color, and beautiful structure and bark that is best revealed in winter.
Avoid Prunus species (Cherries/Plums), as in our area they're increasingly hard to keep healthy and free from bacterial and fungal diseases in our region.
To improve soil conditions, till 4-6 inches of compost into the top foot of soil in the entire strip if you are starting from scratch. If you are adding trees or shrubs to a strip that is already partially planted, use compost as a top dressing after the strip is completely planted. Adding compost just into your planting holes used to be the norm, but research has shown that doing this can actually stunt root growth, and cause roots to circle around and around in the "good dirt" until the crown of the plant is strangled.
After planting, using 2-4 inches of mulch to suppress weeds, retain water, and reduce compaction. Medium-large wood chips are the best mulch to use around all trees and shrubs. The finely-ground cedar bark (aka "beauty bark") looks more uniform, but it compacts over time to form an impenetrable barrier to rainfall and air, which are vital for plant root health.
Remember to leave room in the planting strip to get out of a car and walk through comfortably. And before you put a shovel to the ground, it's very important to make a few phone calls and online searches. The Seattle Dept. of Transportation (SDOT) and the Seattle City Arborist have created a list of approved trees, shrubs, and groundcovers for strips and traffic circles at www.seattle.gov/transportation/treeplanting.htm, or call 206-684-5283. SDOT requires a planting plan to issue a permit, but tree-planting permits are free. Last but not least, call 800-424-5555 to have underground utility lines (water, electric and gas) located and marked for free. These steps are well worth the effort to ensure that you'll never have to remove what you have planted and cared for.