Steeples and Spires For The Shade Garden
If you make gardens, you love to look at them. When you cast your eye across a beautiful landscape there are always some plants that make you stop.
In the shade garden, we have a lot of choices of mounding and low plants. Astilbe, conversely, bloom in graceful spires and brilliant colors. They are eye-catchers in the shade garden. They are a perfect replacement for nonperforming turf in shady areas or as enhancements in the shaded wild edges of the backyard.
Astilbe- Essential Features
Astilbe is desirable to plant in spring, after the last frost date, and in the fall garden before frost begins. It is featured in the post on this site, “In Fall-Invest In The Garden” because it is one of the valuable perennial plants to prepare in fall and get an early start on next summer’s blooms.
The following table will help you quickly decide if this beauty will grow in your garden. Look for your plant hardiness zone, Light, and soil conditions. If those can be accommodated in your garden, check the other features to see if Astilbe is for you.
Varieties of Astilbe
Astilbe come in a considerable range of size, from 6″-to 5′! Please note that you can expect new varieties each year as a popular plant. Look for some of the newer offerings to include more interesting foliage, colors and textures. Astilbe foliage is attractive on its own and extends the plant’s beauty in the garden.
Because the range is so broad and limits their usability in each of our gardens, I will sort the varieties into size ranges. In each case, I will provide name, color, height, and other pertinent information. Here are the groups:
- Dwarf
- Medium
- Tall
Dwarf Varieties of Astilbe
- Cotton Candy- pink, blooms midseason 16″ tall
- Delft Lace-apricot-pink, blue-green foliage, 16″
- Hennie Graafland-(more vigorous alternative to Sprite), pale pink, 14″
- Pumilla-lavender blooms late season 1′
- Pereko-rose, mid-late summer 6-12″
- Sprite-pastel pink, blooms midseason, 1′
- Vision lavender-compact, reliable, short foliage, early bloom, 12-18″
Midsized Varieties of Astilbe
- America-lilac rose, 28″
- Chocolate Shogun-pale pink flowers, chocolate foliage (grown primarily for foliage) midseason, 20-24″
- Deutschland-white, early blooms, 28″
- Fanal-deep burgundy blooms mid-June,2′, bred by the leading developer George Arends
- Elizabeth-lavender-rose,blooms mid-season, 28″ high
- Montgomery-magenta-red, bronze-red foliage, midseason, 22″
- Veronica Klosdale-purple-rose, 2′
Tall Varieties of Astilbe
- Ostrich Plume-salmon-pink, midseason, 40″
- Prof, Van Der Wielen-white, midseason, 40″
- Purple Candle-red-purple, Late season blooms, 42″
- Purple Lance-pink-purple, late August-September, 40″
- Red Sentinel pinkish-red-mid season, 3′
Growing Astilbe
How To Plant Astilbe
Astilbe will thrive in consistently moist, humus-rich soil. It will not accept dry soil or soil which is soaked.
Plant with the roots slightly fanned and pointed downward. Place the crown of the plant one to two inches below the soil and press soil down. Follow the shade instructions for your variety of astilbe. Some accept morning sun and varieties of shade.
Water And Fertilizer For Astilbe
Astilbe has simple but specific requirements. Never dry or wet, but always moist. They grow naturally near ponds and streams.
Astilbe require phosphorus to bloom. Use fertilizer rated 5-10-5 or 10-10-10 and rake the fertilizer into the soil about two weeks before planting. Once astilbe are established, fertilize every spring while the soil is damp.
Ongoing Maintenance
Divide the plants every 4-5 years for best plant health and to increase your supply. If your plants have ideal growing conditions you may divide sooner.
Uses Of Astilbe
Astilbe is a way to extend the garden to its margins and enhancing shaded areas. It is also a desirable cut flower and can be dried. The dwarf varieties are ideal additions to the shaded container garden.
Pests And Diseases Of Astilbe
Pests
Astilbe are pest resistant but if attacked these are the most likely pests with identification and treatment information.
Aphids
Aphids are tiny soft bodied insects which suck the nutrition from plant foliage. They come in various colors often appearing white or green tiny dots on the underside of leaves. It is best to be observent and always checking the underside of leaves as you work or view your garden.
Treat them with sprays of water, with mild liquid soaps, insecticidal soaps and by removing affected leaves.
Leafhoppers
Leafhoppers inject toxins into the plant leaves. This damage appears as a burned appearance on the edge of the leaf. You may also see yellow/green bodies. Treatment is similar to aphids. Use blasts of the hose, remove affected leaves, use mild soap, and insecticidal soaps. There are also yellow sticky traps, do not leave these out indefinitely as they also trap beneficial insects.
Spider Mites
Spider mites are tiny, the adults are reddish-brown in color, they live in colonies on the underside of the leaves and feed by piercing the foliage. They are an arachnid, not a true insect. Treat with predators such as ladybugs, neem oil or insecticidal soaps./
Whiteflies
Whiteflies are sucking insects feeding on the sap of the plant. Look for a white, powdery film on the foliage. Treatment includes beneficial insects such as ladybugs, or parasitic wasps. The best defense is clean growing conditions, sterilized tools, and removal of any damaged or diseased plant material.
Diseases
Leaf Scorch
In Leaf scorch the margins of the leaves turn reddish brown, similar to the damage of leafhoppers. However in this case the damage is accomanied by hot and windy conditions and dry soil. If needed, move the plants to a more damp and shady location.
Leaf Spot
Leaf Spot-is indicated by well defined dead spots on the leaves, this sometimes extends and covers the entire leaf. Try to water the soil and not the foliage.
Powdery Mildew
Powdery Mildew-look for white, powdery areas on the foliage. This is a fungal growth, treat with a fungicide.
Root Knot Nematode
Root Knot Nematode-galls develop on the roots and the plant may appear stunted. Remove all affected plant material and leave the immediate area unplanted for one growing season.
Virus
Virus-Plants are yellow but roots appear healthy. Remove the plants.
Wilt
Wilt-the plants have broken, sunken, dead areas on the stem near the root line. The plants appear, generally wilted. Remove the plants.
Summary,
Astilbe are hardy, herbaceous perennials treasured for large and handsome foliage, often fern-like in nature and tall plumes of blooms. There are eighteen species.
The plant is native to both eastern Asia and North America. Most of the original plants were discovered in mountain areas of both China and Japan.