Plants That Can Survive Oklahoma Weather Year-Round
One of the best things about selecting plants for your central Oklahoma landscaping – especially shrubs and flowering perennials – is the long growing season and plentiful sunshine. At the same time, the worst thing for some plants is the extreme Oklahoma weather, which can be very hot in the summer with very cold snaps in the winter.
It’s important to select plants that can survive Oklahoma’s year-round extremes. A good way to start the selection is to refer to the U.S. Department of Agriculture’s Hardiness Zone Map, which is based on the average annual minimum winter temperature.
A hardiness zone is a geographically defined area in which a specific category of plant life is capable of growing, as defined by climatic conditions, including its ability to withstand the minimum temperatures of the zone.
The zones are determined by the average minimum temperature in the winter months. The temperatures for each zone are separated by a difference of 10 degrees Fahrenheit. For example, the average low temperature of Zone 7 is 10 degrees colder than Zone 8, and the average low temperature in Zone 8 is 10 degrees colder than Zone 9.
Some zones are further divided into sub-zones. Based on the 2012 revised USDA plant hardiness zone map, most of central Oklahoma, including the Oklahoma City metro, is in Zone 7a. Plants selected for Zone 7a should be able to survive winter temperatures between 0 degrees to 5 degrees and, with proper care, tolerate the summer heat.
Hardiness zones are based on the average annual extreme minimum temperature during a 30-year period in the past, not the lowest temperature that has ever occurred in the past or might occur in the future.
Although the plant hardiness information is not foolproof, it’s always wise to stick to plants that are labeled “safe” for your particular zone. It is important to keep in mind that other factors also influence the success rate of certain plants in a particular area.
Wind, soil type, soil moisture, humidity, pollution, snow, and winter sunshine can greatly affect the survival of plants. The way plants are placed in the landscape, how they are planted, and their size and health might also influence their survival.
And, of course, there is the sometimes scorching summer sun to take into account. You want to select year-round plants that not only survive the coldest winter days but also the hottest summer days.
For landscapers in Zone 7a, there is an opportunity to add what are sometimes called “four season” plants – plants that look nice in spring, summer, fall, and even winter. While very few plants are in bloom year round, four season plants can add interest to the landscape in other ways besides flowering.
Selecting Shrubs & Bushes For Your Landscape
There are a vast array of shrubs and bushes to choose from for the central Oklahoma climate, including evergreens and deciduous shrubs. You’ll have choices in all sizes, from groundcover to small trees. Do you prefer the year-round texture evergreen shrubs offer or the autumn color some deciduous plants provide?
You’ll also need to think about size. Do you want dwarf plants that grow beyond a foot or two tall? Short shrubs or medium bushes for hedges? Another issue is whether to plant something exotic or stick with native bushes.
Evergreens are the most popular year-round shrubs for Zone 7a. While the list is extensive, here are some of the more popular varieties:
• Wintercreeper (Euonymus fortunei)
• Yaupon holly (Ilex vomitoria)
• Japanese holly (Ilex crenata)
• Japanese skimmia (Skimmia japonica)
• Dwarf mugo pine (Pinus mugo ‘compacta’)
• Dwarf English laurel (Prunus laurocerasus)
• Mountain laurel (Kalmia latifolia)
• Japanese/wax privet (Ligustrom japonicum)
• Blue Star juniper (Juniperus squamata ‘Blue Star’)
• Boxwood (Buxus)
• Chinese fringe-flower (Loropetalum chinense ‘Rubrum’)
• Winter daphne (Daphne odora)
• Oregon grape holly (Mahonia aquifolium)
The Oklahoma Cooperative Extension Service provides an extensive list of shrubs recommended for Oklahoma weather. This list includes tips on which shrubs will work best into your landscaping for summer heat and winter highlights.
Unlike annual flowers, or even some herbaceous perennials, shrubs are usually planted with permanence in mind. As such, it’s important to carefully select plants to ensure long-term success. It’s also important to consider the plant’s adaptability to the proposed planting site, as well as its mature size.
When selecting shrubs for the landscape, consider each plant’s ornamental characteristics. Consider plant height, width, and shape; foliage color and texture, including fall color; bark attributes; and flowering and fruiting habits, to obtain the right shrub for your landscape design.
The Best Perennials To Use
• Black-eyed Susan (partial or full sun)
• Four O’clock (partial or full sun)
• Hosta (shade)
• Salvia (sun)
• Butterfly weed (sun)
• Shasta daisy (partial or full sun)
• Lavender (sun)
• Bleeding heart (shade or partial sun)
• Hollyhock (sun)
• Phlox (partial or full sun)
• Chrysanthemum (partial or full sun)
• Bee balm (partial or full sun)
• Aster (sun)
• Painted daisy (partial or full sun)
• Clematis (partial or full sun)
• Basket of gold (sun)
• Iris (partial or full sun)
• Candytuft (sun)
• Columbine (partial or full sun)
• Coneflower/Echinacea (sun)
• Dianthus (partial or full sun)
• Peony (partial or full sun)
• Forget-me-not (partial or full sun)
• Penstemon (partial or full sun)
Again, the Extension Service provides a long list of flowering plants that thrive in Oklahoma weather along with recommendations on specific varieties depending on your gardening preferences – cut flowers, showy foliage, large background, edging, borders, and ground cover.