Tracey Payton Horticulture Extension Educator Oklahoma Cooperative Extension Cleveland County 601 E. Robinson, Norman, Ok 73071 (405) 321-4774

New Oklahoma Proven Plants

The Oklahoma Proven Plants for 2011 have been determined. What is Oklahoma

Proven, you ask? They are plant selections chosen by experts in the Horticulture field

that have shown to perform very well in Oklahoma’s climate, which as you know can

be unforgiving. We recommend these plants to residents new to our harsh growing

conditions, as well as businesses and experienced gardeners alike. Each year, a tree,

shrub, perennial, and annual are chosen for Oklahoma Proven status. On some

occasions, a Collectors Choice is also selected.

The tree for 2011 includes varieties of the American Elm

(Ulmus americana): ‘New Harmony’, ‘Valley Forge’, and

‘Princeton.’ These varieties of American Elm are a few that are

shown to have resistance to Dutch Elm Disease, which decimated

our charming elm lined streets beginning in the 1960’s. All the

varieties mentioned are broadly vase shaped with dense canopies

and beautiful yellow fall foliage. However, ‘Valley Forge’ is

upright and arching while ‘New Harmony’ has arching and

somewhat drooping branches. American elms can handle

numerous soil conditions, including salts used for melting ice, air

pollutants, drought, and a wide range of soil pH.

The shrubs selected for 2011 include varieties from the Abelia Collection

(Abelia x grandiflora): ‘Kaleidoscope’, ‘Little Richard’, and ‘Rose Creek.’ These

smaller varieties of Abelia are becoming very popular in the landscape. All of the

varieties mentioned stay small, around 2-3’ wide and 3-4’ tall. ‘Kaleidoscope’ has bright

red stems and lime green leaves tinged with yellow. The leaves of ‘Kaleidoscope’ won’t

scorch in the sun, may have fall color that ranges from deep orange to red, and soft pink

buds turning to white flowers in late spring. ‘Little Richard’ is evergreen with glossy

green leaves in summer that turn pinkish orange in fall, and white flowers that bloom

from summer to the first frost. ‘Rose Creek’ is another evergreen having red stems, new

growth turning from pink to dark green then

purple come fall, and small white flowers

encompassed by rosy pink sepals. These

compact forms of Abelia can be used

successfully in containers, as an accent hedge

or plants, in a grouping, or as foundation

plants. Hummingbirds and butterflies are attracted to these plants, adding another benefit

to incorporating them into the landscape. Abelias prefer sun or part shade with a well

drained and more acid soil.

Giant Coneflower (Rudbeckia maxima) is the perennial

selection for 2011. I couldn’t be more excited about this native

choice, as it is one of my favorite plants. Giant Coneflower has

large grey blue foliage and flowers with bright yellow petals and

a dark inner cone. One reason I love this plant is the flowers are

born in early summer above the foliage quite a bit, and get this: are 5-6’ tall! Giant

coneflower is native to the Eastern part of Oklahoma, but does well throughout the state.

It will do well in moist or dry soils once it is established. This Coneflower will thrive in

full sun, but could also tolerate some late afternoon shade. Deadheading, or removing the

spent blossoms, will encourage another flush of blooms in late summer. Giant

Coneflower works best as a border, or planted in masses. It is a great addition to native

beds, woodland areas, or the cottage garden.

The 2011 annual plant selection is Pink Crystals Ruby Grass (Melinus

nerviglumis) variety ‘Savannah.’ As most warm season grasses, it thrives in full sun and

heat and will survive in areas where other plants may scorch.

Another benefit is unlike some grasses it only grows 18 to 22”

tall. Pink Crystals Ruby Grass is a cute ornamental grass with

traditional glossy green to blue foliage. In late spring it has

bright pink blooms with silky white hairs. In addition, the

flowers keep their color and can be used in flower arranging. Pink Crystals Ruby Grass

is a great addition if you need something to fill in small areas of the flower bed, as a

border, or to add height to container plantings.

The Silver Linden tree (Tilia tomentosa) is the Collectors

Choice selection for 2011. This is a lovely large shade tree that

can get 50’ to 70’ tall. It is tolerant of the urban landscape, high

pH soils, pollution, and can be more heat tolerant than other types

of Linden trees. The Silver Linden makes a great street tree or a

nice addition for a large Oklahoma yard. The leaves are a nice

dark green on the surface and silvery beneath, which offers an interesting contrast when

the wind blows. In addition, small, fragrant white flowers will attract bees in late June or

July and the leaves may have yellow fall foliage. Some cultivars may be selected for

your desired effect, such as brilliant fall color or better performance.

I hope you will consider incorporating one or two of these selections into your

own landscape. For information on other Oklahoma Proven Selections by year contact

our office at 405-321-4774 or go to: oklahomaproven.org.

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