The success of any garden or landscape in Oklahoma depends on selecting plants that can withstand the region’s unique environmental pressures. The state’s climate and soil composition create a challenging, yet rewarding, environment for gardeners. Choosing well-adapted species, from vegetables to trees, ensures longevity and minimizes the struggle against weather and soil limitations, allowing plants to thrive in the Sooner State.
Understanding Oklahoma’s Unique Growing Conditions
Oklahoma’s climate is highly variable, spanning USDA Plant Hardiness Zones 6a in the Panhandle to 8a in the far southeast. Most of the state falls within zones 6b through 7b, which defines the minimum winter temperatures plants must tolerate. The state’s weather is characterized by scorching summers, demanding significant heat and drought tolerance from plants.
The widespread presence of heavy red clay presents another significant challenge. This dense clay soil drains poorly and compacts easily, often leading to root suffocation and waterlogging. Spring weather is highly fluctuating, bringing strong winds, hailstorms, and sudden temperature drops that can damage new growth. These conditions necessitate choosing plants with robust root systems and a high degree of resilience.
Successful Edible Crops
Growing food in Oklahoma requires focusing on varieties that tolerate intense summer heat and adapt to clay-heavy soil. Reliable choices include vegetables that mature quickly in the spring or thrive during the long, hot summers. Amending the clay soil with organic matter like compost is necessary to improve drainage and aeration, especially for root vegetables.
Heat-loving staples like okra, sweet potatoes, and black-eyed peas (cowpeas) perform exceptionally well, continuing to produce even when temperatures soar. Okra needs warm soil for germination and produces continually until the first frost. Sweet potatoes grow from slips and thrive in the long, hot season, forming their tubers underground.
For vining crops, melons such as watermelon and cantaloupe are easily grown in the heat and attract pollinators. Squash varieties, including summer and winter squash, also grow quickly and tolerate the conditions, though they require consistent moisture. Heat-set tomato varieties are recommended, as standard tomatoes often fail to produce fruit when night temperatures remain too high. Bush beans are generally easier to grow than pole beans in clay, as their shallow root systems adapt better to the heavier texture.
Resilient Ornamental Plants and Flowers
Ornamental plants selected for Oklahoma must possess inherent drought and heat tolerance to withstand summer extremes. Perennials native or well-adapted to the prairie environment offer reliable color and structure with minimal maintenance. Coneflowers (Echinacea) and Black-Eyed Susans (Rudbeckia hirta) are excellent examples, thriving in full sun and dry soil while attracting pollinators.
Other resilient choices include plants that provide continuous color and structure throughout the season.
Resilient Ornamental Choices
- Russian Sage (Perovskia atriplicifolia), which produces lavender-blue flowers throughout the summer and requires minimal watering once established.
- Lantana (Lantana camara), a versatile, heat-loving plant that provides continuous color from spring until frost.
- Ornamental grasses like Little Bluestem (Schizachyrium scoparium) and Switchgrass (Panicum virgatum), which are native, extremely heat-tolerant, and add texture.
- Texas Sage (Leucophyllum frutescens), a shrub that tolerates heat, drought, and poor soil, producing purple blooms after rainfall.
- Red Yucca (Hesperaloe parviflora), valued for its striking sword-like leaves and tall spikes of coral-colored flowers.
Choosing these tough, water-wise plants ensures a vibrant display without excessive irrigation demands.
Trees and Shrubs for Longevity
Long-term success depends on selecting woody plants that can handle heavy clay soil and temperature fluctuations. Trees like the Lacebark Elm (Ulmus parvifolia) and the Shumard Oak (Quercus shumardii) are highly recommended for their durability and adaptability. The Lacebark Elm is particularly valued for its disease resistance, wind tolerance, and attractive, exfoliating bark.
The Eastern Redbud (Cercis canadensis), the state tree, is a hardy choice known for its vibrant spring flowers and ability to tolerate a range of soils. Bald Cypress (Taxodium distichum) is highly versatile; despite its association with wet areas, it is remarkably drought-tolerant once established and performs well in clay. River Birch (Betula nigra) is also popular, adapting well to the yearly fluctuation of wet spring soil and dry summer conditions. For smaller additions, shrubs like Junipers (Juniperus spp.) and Deciduous Holly (Ilex decidua) offer excellent evergreen and seasonal interest.