Buckeye Yard and Garden onLine

Read all about perennials and landscape trees and shrubs in the ONLA publications "Perennial Plants for Ohio" and "Landscape Plants for Ohio." The descriptions and photographs of plants were provided for these publications by the OSU ENLT Team along with other industry plant lovers. These full-color publications are available at [ http://Buckeyegardening.com ] for $5.00. Click on "garden store" and then "ONLA plant guides." ONLA members can purchase these in quantities at a reduced price at [ http://onla.org ].

*PERENNIAL PLANT OF THE WEEK. COLUMBINE - (Aquilegia spp.). The columbine world has expanded with all of the introductions in the past several years. There are some really cool plants with dense clusters of flowers raging from pinks to purples to light blues and whites. 'Nora Barlow' for instance, has a double pom-pom pink flower that nods gracefully atop a 30-36" tall plant. 'McKana Giants' have large blooms in a variety of colors. It blooms later in spring and on into the summer. Don't forget the native Ohio columbine (A. canadensis), it's great for woodland areas and has a tendency to spread nicely. The only drawback for these plants is that they are affected by columbine sawfly (Pristophora aquiligae) and columbine leafminer (Phytomyza spp.) so be on the lookout for these critters in the early spring.

*WOODY PLANT OF THE WEEK: CRABAPPLES. The ornamental Malus (apples less than two inches in diameter at maturity) were at their spectacular peak in northeast Ohio this past weekend, just in time for Secrest Arboretum's Plant Discovery Day. Ohio is a major nursery producer of crabapples and it is easy to see why this year with their range of flower and bud color and contrast, range of plant shape from upright to weeping, range in size from dwarfs to 20 footers, and later this season, taxa with yellow to orange to red to purple fruits. Below are just a few of the many apple scab-resistant crabapples for Ohio; check out "Landscape Plants for Ohio" for additional selections.

'Adirondack' - One of the few outstanding crabapples with a narrow, upright tree form. Clean foliage, orange-red fruits, and showy white flowers. Excellent autumn foliage and fruit with combinations of reds and oranges.

'Louisa' - Outstanding weeping form with graceful, arching branches and soft pink flowers. Fruits are a golden-orange color. Other crabapples that are more spreading-weepers rather than true weepers are 'Manbeck Weeper', 'Molten Lava', 'Mary Potter' and 'Candymint'.

'Prairifire' - Rounded to open tree form. Consistent, stunning display of coral-pink flowers. Attractive glossy green foliage with a purple tinge. Purple fruits are ornamental from late June to early December and are paired with orange fall color of the spur leaves.

'Sugar Tyme' - Good rounded overall form, but the flowers and fruits are the main attraction. Sugary white mass of blooms are consistent from year to year followed by showy apple-red fruits that are ornamental well into the winter months.

For still more on crabapples, check out Lake County Nursery's Maria Zampini's article on Mini-Malus in the March 15, 2008 edition of American Nurseryman.

*THE WEEKLY WEED. BYGLers noted that GARDEN YELLOWROCKET (Barbarea vulgaris) is making its annual appearance in Ohio's fields and landscapes. This non-native invasive biennial weed belongs to the mustard family (Brassicaceae), so it is a prolific seed producer. Plants spend the first year in the vegetative stage as tightly clustered rosettes of prostrate leafy stems that are often hard to spot lurking beneath other plants. The weed shows its true colors the second year when it enters the reproductive stage. Abundant clusters of tiny, bright yellow four-petaled flowers borne atop hairless, stout, light green to reddish purple flower stalks appear to "rocket" above 1-2' tall rounded, bushy plants.

Prior to flower production, yellowrocket is sometimes mistaken for other nefarious weeds such as the ever-loathsome GARLIC MUSTARD (Alliaria petiolata). However, a close look at the basal leaves will reveal important distinguishing features. The lobed, shiny dark green basal leaves of yellowrocket are 2-8" long, with 1-4 oppositely arranged lateral lobes and a large terminal lobe. The terminal lobe has a heart-shaped base.

Yellowrocket control measures include herbicide applications, hand-pulling or cultivation prior to seed production. The weed is susceptible to glyphosate (e.g. Roundup) as well as triclopyr; however, since this is a biennial weed, it is important to target the prostrate rosettes as well as the bushy flowering plants. Unfortunately, seed production has already commenced in southern Ohio, so while control measures will reduce the overall seed bank for coming seasons some seed has already been dispersed this year.

For more information, see:

• Natural Resources Conservation Service Garden Yellowrocket Info
• Robert W. Freckmann Herbarium