Oklahoma Proven Plants for 2020

Oklahoma Proven Plants for 2020

Tom Ingram: Ask a Master Gardener

Sunday, March 1, 2020

Q: I have a friend who suggested I try some Oklahoma Proven plants. What is he talking about? BC

A: Oklahoma State University has a program called Oklahoma Proven, where plants are tested to see how well they perform in the somewhat unpredictable and oftentimes brutal Oklahoma climate. Each year, a variety of plants are evaluated, and several are selected to become that year’s Oklahoma Proven selections. The winners for 2020 are out. You may or may not be familiar with some of these, but any of them would be great additions to your garden.

The tree for 2020 is the Hornbeam (Carbines species). This tree does great as an understory tree and needs little pruning. It is slow growing and can be used as a tree or a hedge, typically reaching heights of about 20-30 feet. It grows well in full sun to part shade. Plant in a place with well-drained soils.

The shrub this year is the Red Yucca (Hesperaloe parviflora). This perennial has evergreen leaves from 2-3 feet in length while the flower stalks can rise up to 5 feet with coral-colored tubular flowers. It’s drought-resistant, and the flowers can attract hummingbirds. This one would be great for xeriscape or low-maintenance gardens.

The perennial for 2020 is the Golden Variegated Sweet Flag (Acorus griminess “Ogon”). This grassy plant is native to Asia and will do well in full sun to part shade but will appreciate some afternoon shade if planted in a full-sun location. Boggy or consistently moist areas are not a problem for this one. The Ogon cultivar is a dwarf variety that should grow to 6-12 inches tall, making it great for a border or an interesting filler plant.

The annual is the Brazilian Verbena (Verbena bonariensis). This plant usually has a 1-foot-tall base of dark green leaves with flower stems of up to 3½ feet. Even though it is technically a tender perennial, in Oklahoma it is considered an annual. If sheltered, it might survive the winter. Even if they don’t, they are self-seeding, so you may be able to enjoy them for years to come. It is heat- and drought-tolerant and has the added bonus of being a great attraction for pollinators.

Oklahoma Proven has been around for 20 years and has compiled a book that can be purchased or downloaded for free. Check under the Hot Topics link on our website if you would like a copy.

Garden tips

• If you had previous damage to the tips of pine tree limbs, especially non-native pines, it may be diplodia tip blight (a fungus) or Nantucket pine tip moth damage. Both are controlled with pesticides starting this month. Call the Master Gardener office for recommendations.
• Preemergent herbicide to control crabgrass and other summer weeds should be applied by the middle of March.
• Divide and replant overcrowded, summer- and fall-blooming perennials. Mow or cut back old liriope (monkey grass) and other ornamental grasses before new growth begins.
• The Master Gardener online plant sale continues through April 1.