Print this page

Skagit Gardens
Monrovia

Perennials are forgiving plants that re-appear each year growing and blooming for extended periods. Most perennials are long lived bringing many years of enjoyment.
Perennials come in many forms. Some will retain their foliage year round (evergreen), while others (herbaceous) recede into dormancy, and after a short rest, produce abundant new foliage and flowers.

Planting
Proper soil preparation is the single most important factor in having success with perennials. Organics will retain moisture in summer and improve drainage during winter. In addition, by incorporating fertilizer you will provide nutrients essential to sustain growth and promote flowers.

Once the soil is properly prepared you are ready to plant.   Amend your soil with Bumper Crop or Paydirt. Planting early in the day is best.   Remove the plant from its container (root ball intact) and set deep enough into the soil so that the roots are well covered and the plant is securely anchored.   Water thoroughly and check frequently for the first few days until it has “settled in” to its environment. I  f you cannot plant perennials right away, water them thoroughly and shelter them in the shade and out of the wind.

Maintenance
Water deeply early in the morning once or twice per week.   Most perennials prefer deep infrequent waterings.  Mulch  will cool the soil, eliminate weeds and reduce moisture loss.   Black Forest Compost is excellent for both mulching and amending the planting site.  Fertilize every six weeks throughout the growing season.   Apply Best 16-16-16 or Master Nursery All-Purpose Plant Food (water soluble).  Pinch any leggy growth and remove faded/spent flowers in order to promote new foliage and flower production.

Clean: Most perennials enter a dormant period at some point during the year, usually during winter. This is an ideal time to cut back, clean up and divide your perennials. Remember, these are tough plants and can survive most anything.

Dividing
When perennials become overcrowded, flowering declines, healthy growth is limited to the perimeters of the plants, and they look shabby. A good way to rejuvenate such perennials is to divide them, either in fall or early spring. Divide six to eight weeks before the first hard frost, so roots get established.

A day or two before dividing, thoroughly moisten soil around the planting and prepare the bed where you will replant. To divide, break up the soil around the plant, cutting 6 to 12 inches beyond its perimeter. Dig under roots to free them. If the clump is too heavy to lift from the ground, cut it into sections.

Tease soil from the root ball, then make divisions. Note natural dividing points between stems or sections. Some perennials can be pulled easily into clumps by hand. Or use a knife or small pruning saw. Good-sized divisions will grow and bloom more quickly than small sections. Trim any damaged pieces from the divisions. Replant as soon as possible, then keep divisions well watered while they get established. You can also plant in containers (good if divisions are very small), to set out later or share with other gardeners.

Shady Situations
When planting, the most important steps are to properly prepare the soil, and to carefully select plants that are suited to the light levels and exposure of your garden. For the novice, though, interpreting gardening terminology can be confusing, especially with respect to lighting.
The term “shade” really applies to several different situations. First, there is deep shade, such as that found under evergreen trees—perhaps the most difficult situation in which to garden. Many plants do thrive in deep shade, but usually prefer the dappled light and moist, rich soil found under deciduous trees or in woodland gardens. Shallow-rooted ground covers such as Ajuga, Vinca, Hedera, and Galium do well under large trees, protected from harsh winds and extreme temperatures, but without having to compete for water and nutrients.

Other plants prefer “partial shade,” where they receive four to six hours of sun in the morning, but are protected from the hot afternoon sun by larger plants, or by man-made structures. Plants preferring partial shade are a good choice when planting along the east side of a house.

Diagnosing Plant Yellowing
Wouldn’t it be nice if plants could talk?  When a plant turns yellow, there’s something wrong. But what do the symptoms indicate?
Water stress. Too much or too little water turns leaves light green or yellow, starting at the tips or edges. Plants may be stunted. Leaf margin may also turn brown and leaves may die.

Sunburn
Too much light makes leaves look bleached, especially on the top of the plant. Lower leaves and those shaded from the sun will be healthy.

Nutrient deficiencies. Nitrogen-deficient leaves turn pale green, then yellow, then drop, starting with the oldest leaves. New leaves may be stunted. On iron-deficient plants, the youngest leaves yellow first.
Disease. Many diseases and fungi turn leaves yellow with spots, streaks or all over, and twist stems and flowers. If you suspect a plant is diseased, we recommend you bring a sample of the affected part of the plant to the garden center for diagnosis.

Easy Perennial Selection—look to the light
Plants have preferences—especially regarding light and moisture.
Many perennials—such as Heliopsis, Lavandula, and Aster—love eight or more hours of sun. Other sun-adoring plants include Coreopsis, Euphorbia, Buddleia, Boltonia, Achillea, Helianthemum, Gypsophila, and Phlox.

Versatile perennials for sun and part-shade include Polemonium, Trollius, Filipendula, and Platycodon. Digitalis, Bergenia, Campanula, and Aquilegia prefer moist soil. Given six hours of sun daily, Dianthus, Hedera, and Bergenia can provide either a sunny border or carpet beneath a leafy tree.

Reminiscent of fair-skinned Victorians, the shade-loving flower gentry include Dicentra and Heuchera, thriving with four to six hours of daily sun. With sufficient moisture, Astilbe, Ligularia, Aruncus, Chelone, and Japanese Anemone will display their beauty from early summer into fall.