I was vacationing in Arizona last year and saw some interesting plants. Will they grow here in Oklahoma? KF

While you don’t mention a specific plant, let’s talk about some general information to use when selecting plants for your landscape.

One of the main things to consider other than water requirements and amount of sun your plant would receive, is the growing zone rating for this particular plant.

The USDA has divided the United States into several growing zones. The primary growing zone chart references cold hardiness. Tulsa County is in growing zone 7a which means that, on average, winter lows shouldn’t be lower than 0 to 5 degrees. If we have an average winter, plants rated to grow in zone 7a shouldn’t have a problem surviving here in Tulsa County.

But how often do we have an average winter? Because of this, plants that are rated for growing zones 7 and higher can get damaged or killed when weather gets below zero degrees. We all remember a very cold snap a couple of seasons back where Tulsa lost a lot of crapemrtles. This is because we got down in the -15-degree realm. So far this season our coldest temps were down in the 2-to-3-degree range back in December. This is within growing zone 7 parameters so we should be good. But as we all know, winter isn’t over yet.

Growing zones can also help determine which plants are classified as annuals or perennials here in Tulsa County. A variety of plants are considered annuals here because we get too cold. But, if you plan ahead and grow your zone 8 and above plants in containers that you can move indoors during the winter, you’ll be able to grow those here in Tulsa County.

An example of this would be tropical hibiscus. Tropical hibiscus is rated for growing zones 9 through 11…warmer climates. But all you need to do is bring your tropical hibiscus inside during the winter and then return it outdoors when the weather warms back up.

Plants that are rated as perennials for our area would be plants that are rated to survive our average winter temperatures. But it’s possible for a plant to be rated perennial in zone 7 but then we get a few days of zone 5 temps (-20 to -15 degrees) and that perennial just became an annual that didn’t survive the winter.

We also need to factor in microclimates. Microclimates are areas that tend to remain warmer or cooler that the surrounding area. For example, you might live in a bit of a valley or up on a hilltop. Each of those are going to be a little different than the surrounding averages. All this to say, growing zones are really meant as a general guideline rather than a guarantee on plant survival.

To get back to the original question, once you find the name of the plant from Arizona you are interested in, check the growing zone on that plant and base your decision on whether it is appropriate for our climate. You’ll be a much happier gardener if you do.

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org. Photo: OSU Ag. Communications