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perennial solutions chinensis ‘Visions’

This deer-resistant variety also attracts hummingbirds and can be utilized in your marketing programs.

stilbes are very erect to arching, plume-like flower during the spring or fall. For By Paul Pilon popular shade panicles that rise above the foliage quart production, a crown con- and woodland on slender upright stems. Astilbe sisting of 1-2 eyes, or shoots, is garden perenni- chinensis ‘Visions’ is a showy culti- commonly used. For larger con- als. They form var that forms compact foliage tainers, such as a 1-gal., divisions beautiful mounds of -like mounds with green to bronze- containing 2-3 eyes are commonly foliage bearing tiny flowers on green glossy reaching 9-12 used. In most cases, container inches high. Flowering occurs in growers do not propagate astilbe early summer, forming pyramidal- ; rather, they purchase A shaped 14- to 16-inch-tall plumes bareroot divisions or large plug full of small, fragrant, raspberry- liners from growers who special- red flowers. are often ize in astilbe propagation. used for cut flowers, as container ‘Visions’ is not a patented culti- items, in mass plantings or small var and can be propagated by any groups, as border and as grower. There are two fairly new groundcovers in shade gardens. introductions with the Visions ‘Visions’ can be easily produced name, ‘Vision in Pink’ and ‘Vision in average, medium-wet, well- in Red’; these are patented culti- drained soils across USDA vars. Growers should note that Hardiness Zones 4-9 and AHS unlicensed propagation of these Heat Zones 8-2. Unlike most cultivars is prohibited. astilbe that require heavy shade, prefers par- PRODUCTION tial shade and can tolerate more ‘Visions’ is available to the sun and drought-like conditions. marketplace as bare-root plants Although they can tolerate more or large plug liners. They are water stress than most astilbes, commonly planted in quart or 1- Astilbe chinensis should not be gal. containers immediately after allowed to dry out, as scorch they have been received. Growers is likely to occur. These slow- commonly them in bark- spreading, rhizomatous plants and peat-based growing mixes, belong to the family, which have good drainage and a which contains several commonly fair amount of water-holding grown perennials such as berginia, ability. When planting, the woody heuchera, heucherella, , crown should be placed in the saxifrage and tiarella. center of the pot with the crown 1 slightly covered (no more than ⁄2 PROPAGATION inch) or just exposed after they Astilbe ‘Visions’ is propagated are thoroughly watered in. vegetatively by division. Planting the crown too deep will± Divisions of astilbe are best done lead to crop variability and All photos courtesy of Sawyer Nurseries.

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82 GPN August 2005 cultureconnection

losses. After planting, I would Astilbes should be kept evenly allowing the substrate to dry recommend drenching with a moist throughout production. slightly between waterings. broad spectrum fungicide such as Water stress is likely to cause the During production, the pH or Banrot (Scotts Co.) or a combina- leaves to become scorched, often acidity of the media should be tion of Subdue Maxx (Syngenta rendering the plant unsalable. I maintained between 5.8 and 6.2. Professional Products) and recommend watering thoroughly Feeding is generally not neces- Cleary’s 3336 (Cleary Chemical). when irrigation is required and sary during the first few weeks of

production. When actively grow- ing, astilbes are moderate feeders requiring a controlled-release fer- tilizer incorporated at a rate equivalent to 1 lb. of nitrogen per yard of growing medium or 50- 100 ppm nitrate delivered under a constant liquid fertilizer pro- gram. Astilbes are sensitive to high salts and may become scorched and have damaged roots if the soluble salt levels are allowed to build up. Monitor the soluble salt levels routinely and leach them out with clear water if the EC rises above 2.0 using the 2:1 extraction method. Astilbes can be successfully forced into bloom either by planti- ng them in the late summer and over-wintering the established plant in the finished container or by planting an over-wintered bareroot division in the early spring. Astilbes require cold in order for them to produce a bloom; at least 10 weeks of cold at 35-45º F should be sufficient. ‘Visions’ are usually grown at an average temperature of 65° F. At this temperature they will reach a finished size in 6-8 weeks and will be flowering in about 12 weeks.

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be reached by E-mail at While forcing during naturally if the growing medium has European producers. Large plugs [email protected]. short days, it is beneficial to pro- insufficient drainage. are more difficult to find but are vide long days using night inter- often available from a few peren- GPN ruption lighting. Long-day condi- AVAILABILITY nial plug suppliers. LearnMore tions will decrease the time Bareroot divisions of astilbe For more information Paul Pilon is head grower at Sawyer related to this article, go to needed to reach flowering. ‘Visions’ are readily available Nursery, Hudsonville, Mich. He can www.gpnmag.com/lm.cfm/gp080506 ‘Visions’ does not require from a number of domestic and height control if it is grown with adequate spacing between the plants. When grown under high plant densities, its plant height can be controlled by applying B- Nine (Chemtura Corp.) at 2,500 ppm or Sumagic (Valent USA) at 5 ppm to the foliage as the plant canopy begins to enclose or once the inflorescences begin to elongate. Two applications applied seven days apart will provide an adequate reduction of the flowering stalk without altering the overall appearance of the plant. These are consid- ered Northern rates and should be adjusted accordingly in other parts of the country. Over-wintering astilbes is rela- tively simple. In the late fall, trim the plants back to 2 inches above the top of the container. Once they are trimmed, group the pots together inside a coldframe, greenhouse or outdoor produc- tion bed. In colder zones, I would also recommend covering them with a frost-protective fabric dur- ing the winter months. During this season, if there are periods where the temperatures remain above freezing, open the cold- frame doors or provide ventila- tion during the day to keep the temperatures inside as cool as possible. Provide adequate venti- lation any time the outdoor tem- peratures are above 40° F.

PESTS AND DISEASES Astilbes are not susceptible to many insect pests. Aphids, spi- der mites and whiteflies are the most prevalent pests. None of these pests require preventative control strategies. Growers should have routine scouting programs to detect their pres- ence early and to determine if and when control strategies are necessary. There are only a cou- ple of diseases associated with the production of astilbes. Crown rot caused by Fusarium or Pythium is likely to occur when crops are over watered or

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