Updated on January 13, 2025 by Ruth
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You’re eager to get your garden started, but before you dive in, you keep hearing about this mysterious “planting zone.” What exactly does it mean, and why is it important? While your planting zone is a key piece of information, there are other crucial factors to consider if you want your perennials to not just survive, but thrive. Let’s delve into the world of growing zones and beyond to ensure your garden flourishes.
Table of Contents
What is a planting zone or growing zone
The USDA has created a plant hardiness zone map which divides the country into growing zones 1-10, with zones 1 and 2 covering parts of Alaska, 3 being the northern parts of Montana, North Dakota, and Minnesota, and zone 10 is the southernmost part of Florida plus a few hot spots in California and Arizona.
These zones focus on the cold temperatures that each area receives so that you can determine if a perennial plant will survive the winter in that growing zone. This matters for particular varieties or unusual crops, so that you know if a plant needs a little extra protection in the winter.
The growing zones are updated annually, as the USDA collects data on actual temperatures for the previous year.
What is Delaware’s growing zone? Delaware is considered growing zone 7b as of 2023. Zones 7A and 7b cover all of Delaware, parts of eastern Maryland, and into Virginia and Kentucky. That’s a pretty wide range, which is why we have to look at a few more details.
What about summer temperatures?
The zone hardiness will tell you if a plant will stand up to cold weather. But what about hot weather? Not all plants, trees, or flowers can handle hot weather or intense humidity.
This is when you need to know your particular growing area. Do you have 2 weeks or 2 months of hot weather in the summer? Do you have high humidity or low humidity? Does it rain a lot or not at all?
You need to learn about the particular plants that you want for your garden and how the plants feel about heat.
Delaware can have a couple of hot weeks in the summer which test you and your plants’ endurance. Make sure that your plants are those that can still thrive in those temperatures.
With sufficient water, most plants can survive a brief spurt of hot weather for a few days. Unless it is a heat-tolerant plant, however, extended weather over 100F will cause many plants to wither.
Consider rainfall
Look at the rain patterns in your area. Do you get rain every week or hardly at all? Will you have to add water most weeks? Is it humid or arid—think of the difference between New Orleans and Phoenix. Different plants will do well in a humid environment than will flourish in a dry area.
In Delaware, we usually have regular rainfall for most of the growing season. However, there is often a time of 3-4 weeks in the summer when there is no rain at all. Will these plants survive that or will you need to add water?
Sunlight
Perennial plants can be flexible in their sunlight requirements, with most doing pretty well with about 6 hours of sunlight. However, if you want your perennials to flourish, pay attention to those sunlight needs. A sun loving perennial will produce more flowers if it gets more sunlight. If you see the sun symbol and a half-sun symbol on the plant tag, that means that flower likes full sun but can handle half day sun. The plant will grow larger and be more robust in full sun. It will still grow and produce flowers in half sun, but it will not be as big.
A shade-loving perennial will be happiest in an area where it receives filtered sun or less than four hours of sun each day. Shade-loving perennials can wind up with sunburn and no flowers if they get too much sun.
Pests and diseases
It is helpful to find cultivars that are disease and pest resistant for the types of insects in your area. Choose plants that are less prone to any common issues in your area.
This is where finding native perennials is helpful, as these are the plants that have adapted to the cold and the heat, the rain and the dry spells, the bugs and the humidity, and yet they can grow, thrive, aid the pollinators, and produce flowers.
Soil types
Different plants like different types of soil. Be sure that the plants you consider are well adapted to the type of soil that you have. Most perennial plants can adjust to soil types and pH, but there are some that require a more acidic or more alkaline pH or a more sandy soil. It’s definitely worth checking ahead of time in case you need to do some soil amendments for the plant. If you do need specific soil amendments, then you will most likely need to do that each year.
Again, native perennials are well adapted to the soil in your area and are most flexible in their requirements.
Where can you find plants that will grow well in your area?
Matching up plants and growing zones can be as simple as going to your local garden center or farm market. Look for a market where they are growing the plants themselves or are working with a local grower. A store that has plants shipped in from 1000 miles away most likely does not have perennials that are adapted to your growing area. Plants from Virginia will still be in our growing zone: plants from South Carolina can be growing zone 9.
Another benefit of visiting your local farmer or plant nursery is that you will be able to ask questions about the plants and their growing requirements. In addition, you are supporting the grower and their efforts to keep plants in your area.
Conclusion
Mastering your planting zone is the first step to a successful garden, but it’s just the beginning. By selecting the right plants from a local source, you’re not only ensuring they’re suited to your zone but also supporting your local community. Remember, gardening is a journey of learning and experimentation, so don’t be afraid to try new things and see what works best for your garden. With a bit of knowledge and a green thumb, your Delaware garden will flourish year after year.
If you are close to our farm near Wilmington, Delaware, please come visit! We have many plants, including numerous native varieties, from March through November. We grow a lot and work with a local grower to supplement what we don’t have room to start. If you are not nearby, please find a nursery or farm near you who is growing. I know you will find lots of interesting plants. Thank you for your interest in sustainable agriculture!
Happy growing!
~ Ruth
Additional resources
https://www.almanac.com/what-are-plant-hardiness-zones
