Extension

Gardening can be a challenge, even for the most seasoned growers. Fortunately, the Oklahoma Proven plant selections can help make choosing plants for the garden and landscape more successful.

 

Each year horticulturists choose plants for the Oklahoma Proven program that are appropriate for Oklahoma landscapes. Now in its 24th year, Oklahoma Proven chooses a tree, shrub, perennial and annual that have been proven to grow well in Oklahoma’s diverse climate.

 

The selections for 2023 include: tree – Acer buergerianum, Trident Maple; shrub – Ilex verticillate, Winterberry Holly (dwarf cultivars – Little Goblin, Berry Poppins, Red Sprite); perennial – Malvaviscus arboreus var. drummondii, Turk’s Cap; and annual – Plumbago auriculata, Cape Plumbago.

 

Native to China, Korea and Japan, the Trident Maple is a small deciduous tree that is typically a slow grower, reaching about 20 to 25 feet tall. It’s easily grown in average to medium moisture and well-drained soil, and prefers full sun, but can be placed in partly shaded areas of the landscape. It can tolerate some drought, as well as soil compaction and air pollution, which also makes it a good choice for street plantings in urban areas. Leaves are glossy green on top and pale green underneath. This tree features flaky bark that reveals an orange-brown inner bark on mature trunks.

 

Winterberry is native to the eastern part of North America. It’s a deciduous holly but doesn’t feature the sharp teeth on the leaves commonly found on other hollies. Bright red berries remain on the branches throughout the winter, adding a splash of color in the landscape. Winterberry is a globular, medium-sized shrub that grows to about 10 feet tall, but under some circumstances can grow up to 20 feet tall. The dwarf cultivars that have been developed are perfect for small spaces. An added bonus is the dwarf varieties grow well in containers, which can be perfect for those with limited outdoor space.

 

Turk’s Cap has bright red flowers resembling a hibiscus flower that never fully opens. The overlapping petals form a loose tube that resembles a Turkish hat. These flowers appear later in the heat of the summer and early fall. Turk’s Cap is a good ornamental for shady landscapes, but under cultivation, can adapt to and thrive in conditions such as full sun and heavy soil.

 

Unremitting sun, often found in Oklahoma, can cause the leaves to become rougher, smaller, darker and puckered. Once established, Turk’s Cap is very drought tolerant. Hummingbirds, butterflies, moths and other insects benefit from the plant’s nectar.

 

Cape Plumbago is native to South Africa and is a weak-stemmed perennial evergreen shrub that can grow about 7 feet tall and 8 to 10 feet wide in its native habitat, but it is treated as an annual in Oklahoma where it generally reaches only 2 to 4 feet high and wide each season. It can be grown in containers, which makes the selection a great choice for patios and decks. This plant is kept compact in the landscape by periodic pruning. If grown in pots, hard pruning will be necessary as the pots should be moved indoors during the winter. Hard pruning will encourage new growth for the coming season. While overwintering indoors, store in a cool, dry, dark corner of a basement or garage. Cape Plumbago grows best in organically rich, fertile and well-drained soil in full sun to part shade. If planting in the landscape, select a spot that is protected from strong winds. While it thrives in consistently moist soils, established plants are moderately drought tolerant.

 

Visit the Oklahoma Proven website to see more detailed information about the 2023 selections, along with color photographs from all of the collections over the past 24 years.