If you live in Tulsa County, you’ve probably noticed that our weather likes to keep us on our toes. From surprise cold snaps to hot and humid summers, knowing your plant hardiness zone can make all the difference for your garden. Understanding Tulsa’s USDA hardiness zone helps you choose plants that are better suited to our climate, setting your garden up for long-term success.
USDA Plant Hardiness Zone
According to the USDA Plant Hardiness Zone Map, the Tulsa metro area is primarily located in Cold Hardiness Zone 7a, with some surrounding areas falling into Zone 6b, where winter minimums can occasionally reach −10°F. In terms of heat tolerance, Tulsa experiences long, hot summers and typically falls into Heat Zone 6b – 7a, averaging 90–120 or more days per year with temperatures above 86°F, an important factor when selecting heat-resilient plants.
Container Preparation and Planting
Always clean used containers before replanting and decide how the plants will be arranged in the pot. Cover the drainage hole with mesh screen or any permeable material such as a coffee filter, then fill container with soil to about one inch from the top. Adjust each plant root ball depth as needed to allow the top-most root of each plant to be even with the surface of the potting soil, lightly press each plant into place. As a last step, water thoroughly.
Air Circulation and Spacing
This might be a less-spoken topic, but air circulation and spacing are vital aspects of a successful garden. If your plants are too close together, they might suffer pest problems due to air stagnation. Heat or wind can damage seedlings or transplants, and herbicide may drift from adjacent properties. Some solutions that can be implemented include barriers, fencing, shrubs, supports and plant spacing.
Know Your Sunlight
Have you ever noticed those tags at the nursery that say full sun or part sun and wonder what exactly that means? You can refer to the next table the next time you’re buying plants to ensure you can offer them as much or as little sunlight as they need.
| Full Sun | 6 or more hours |
| Part Sun | 4-6 hours |
| Part Shade | 2-4 hours |
| Shade | Less than 2 hours |
These terms are also used:
- Light shade: dappled shade or intermittent shade under open canopy trees.
- Moderate shade: mostly reflected light such as on forest floors.
- Heavy shade: without any direct sunlight
Soil
There are different types of soil, each with its own characteristics that make it unique. Knowing the characteristics can help you select the best option for your plants.
- Sandy: Leaching, drying, easy to till, good rooting.
- Clay: Poor drainage, difficult to till, poor rooting, fertile.
- Loamy: Free movement of water and air. Good water retention. Fertile, little resistance to tillage.
Tip: Organic matter improves sandy and clay soils.
You can test if the soil is dry enough to be worked by performing a drop test. If this is your first time using the area, rent or borrow a roto-tiller and double-dig the soil to a depth of one foot. Remove any weeds by chopping them with a hoe, tilling and raking, or pulling them out by hand. Add two inches of organic matter and incorporate it thoroughly into the garden area. If the ground is level enough, use a Mantis-type tiller; otherwise, use a spading fork. If you are planting seeds, make sure the soil texture is finer than it would need to be for transplants.
Final Gardening Tips
- Sample soil and have it tested every three or four years.
- Apply fertilizers in the recommended manner/amount.
- Use organic materials such as compost if available.
- Use Oklahoma recommended plant varieties.
- Remove extra seedlings early, while they’re still small and easy to manage. This way the remaining ones have enough space to grow properly.
- Avoid excessive walking or working on your garden if foliage and soil are wet.
All the information on this blog post was graciously provided by OSU Extension – Tulsa Master Gardeners. To learn more about Tulsa Master Gardeners, visit www.tulsamastergardeners.org.