When starting a garden or landscaping your yard in Maryland, it’s important to know what planting zone you’re in. Maryland stretches across several USDA plant hardiness zones due to its range of climates from the Allegheny Mountains to the coast. Learning your zone helps determine which plants can thrive in your area.
The United States Department of Agriculture has created a map dividing North America into different hardiness zones based on each area’s average minimum winter low temperature. This helps determine which plants will most likely thrive and survive the winter in a particular zone. Maryland stretches across several zones, ranging from 5b in the mountains to 8a along the Eastern Shore.
Knowing Maryland’s USDA zones is vital for garden planning and selecting suitable trees, shrubs, flowers, fruits, and vegetables. The lower the zone number, the colder the winters. Most of the state falls into zone 7a, including central Maryland and the Baltimore area.
Maryland gardeners need to use the 1990 USDA Hardiness Zone map and microclimate considerations to determine which plants can withstand their region’s winter temperatures. You can learn more about the Maryland USDA zone map in our guide. By the end, you’ll better understand a plant’s hardiness and how many degrees Fahrenheit it can handle any Maryland growing zone. (Read What Planting Zone Is Virginia)
What Are USDA Planting Zones?
The United States Department of Agriculture (USDA) created a map dividing North America into 13 planting zones based on each region’s average minimum winter temperature. The lower the zone number, the colder the climate.
Each zone spans a 10°F range of average low temps. Zones are further divided into “a” and “b” indicating 5°F differences within the 10-degree bands. For example, Zone 6a averages minimum lows of – 10 degrees to -5 degrees while Zone 6b averages -5° to 0°F.
The USDA map provides helpful guidelines for growers and gardeners to determine which plants can survive the winter in their planting zone. However, it’s important to note that microclimates also impact local conditions.
What Planting Zones Are Found in Maryland?
Maryland stretches across USDA plant hardiness zones 5b through 8a due to the range of climates from the mountains to the coast.
- Western Maryland mountains: Zone 6a moving into 6b cover the Northern Part.
- Central and Western Maryland: Zones 6b and North Potomac 7a
- Central Maryland, including Baltimore: Zone 7b
- Eastern Shore and Southern Maryland: Zone 8a and Zone 9
The different zones allow for a wide variety of plants to thrive in Maryland gardens and farms. The zone also shows the farmer the average first and last frost dates, which affect growing seasons.
What is Maryland’s Most Common Planting Zone?
Most Maryland falls into Zone 7a, including central and western parts of the state. Zone 7a has average annual minimum temperatures between 0°F and 5°F.
This means plants need to withstand winter temperatures falling from 0°F to 5° below zero. The last spring frost is typically around April 15, and the first fall frost is around October 15, allowing for a generous frost-free growing season.
Zone 7a covers an expansive area of the eastern half of the U.S., including much of Virginia, western North Carolina, southern Pennsylvania, New Jersey, southern Ohio, and beyond. (Read Why Are My Zucchini Turning Yellow)
What Plants Grow Well in Maryland’s Zone 7a?
Knowing your planting zone helps determine the best vegetation and crops for your Maryland garden. Here are some popular choices for Zone 7a:
- Flowers – roses, tulips, black-eyed Susans, magnolias
- Shrubs – hydrangeas, forsythia, spirea
- Trees – birch, maple, dogwoods, fruit trees like apples, cherries and peaches
- Vegetables – tomatoes, sweet corn, squash, broccoli, lettuce, spinach, beets, potatoes
- Herbs – parsley, thyme, sage, dill, chives, oregano, mint
- Fruits – strawberries, raspberries, blackberries, grapes, blueberries
- Perennials – coneflowers, salvia, iris, phlox, asters, hostas, daylilies
Remember to confirm that plants are rated down to Zone 6b or Zone 6a to give a safety buffer for unusual cold snaps.
Generally, a wide range of plants grow in zones 6 through 9. However, in Maryland, planting zones range from 5b to 8a. Hardier plants vary and grow in Zone 4 (-15 temps and shade), zone 3 or lower. You would need to use the map to see where these are.
What is Zone 8a Found in Maryland?
A general area of Southern Maryland and the Eastern Shore region fall into Zone 8a. This warmer zone has average minimum winter lows between 10°F to 15 degrees Fahrenheit.
The last spring frost in Zone 8a Maryland is typically around March 20. The first fall frost lasts until around November 20 or later, allowing an exceptionally long growing season. Great Zone 8a plants include camellias, gardenias, hibiscus, magnolias, figs, and citrus trees like satsumas, Meyer lemons, and kumquats. Vegetable gardens can stretch right into winter with broccoli, Brussels sprouts, carrots, and more.
How Does Elevation Impact Maryland’s Planting Zones?
While most of Maryland is Zone 7a, higher elevations in western parts of the state dip into slightly cooler zones. The mountainous west, including Garrett County, falls into Zone 6 a, with average lows between -10°F and -5°F.
At these chilly high elevations, gardeners should choose plants rated down to USDA Zone 5 a or USDA Zone 5b to ensure they can withstand cold mountain winters. Wind and other microclimate factors also come into play at higher elevations when selecting vegetation. (Read Are Zz Plants Toxic To Dogs)
When Should I Plant in Maryland?
Most gardeners use the USDA plant hardiness as a guide of the USDA zone’s last frost date to help determine when to start planting in the State of Maryland garden each year:
- Start cool weather veggies like peas, spinach, and kale 4-6 weeks before the average final spring frost.
- Begin warm-weather crops like tomatoes, peppers, and beans indoors 6-8 weeks prior—to transplant after danger of frost.
- Direct sow warm season annuals like zinnias and marigolds after your zone’s last frost date.
- Transplant tender perennials and summer bulbs 2 weeks after the average final spring frost.
- For fall gardens, plant cool weather crops in late summer, 50-70 days before the first fall frost.
How Do I Use the Zone Map for Maryland?
Here are some tips for utilizing the USDA plant hardiness zone map for Maryland gardening:
- Look up your zip code online to find your exact zone. Local extension offices can also provide zone information.
- Use your zone as a starting point when choosing plants, then consider microclimates in your specific area.
- Check plant tags for recommended zones when shopping at nurseries and garden centers. Select plants rated for your zone and, ideally, one zone colder.
- Remember, zone ratings indicate the average coldest temps. Unusual cold snaps may still damage plants at the upper end of their rated zone.
- Monitor weather forecasts for the coming season and choose plants accordingly. For example, pick more cold hardy options if an extra cold winter is predicted.
What is Maryland’s Interactive USDA Zone Map?
In 2012, the USDA released an interactive update to their traditional static plant hardiness zone map. The new map offers more detailed data on microclimates.
Search the interactive map by zip code and click between the classic and new USDA zone maps for Maryland. The interactive map also provides:
- Specific first and last frost dates.
- Chill hours.
- Growing degree days for very localized regions.
Check out the updated interactive map at planthardiness.ars.usda.gov to get ultra-precise growing data for your area to assist in choosing the perfect plants. (Read Can You Grow Asparagus In A Pot)
Key Takeaways on Maryland Hardiness Zone Planting
- Maryland stretches across 5b to 8a, with most of the state in Zone 7 a on the hardiness map.
- Higher elevations like western mountains fall into Zone 6a and 6b.
- The Eastern Shore and southern Maryland dip into warmer Zone 8a.
- Use zones to pick suitable plants, then refine choices based on microclimates.
- Check the interactive map for your zip code’s precise zone, frost dates, and growing data.
Knowing your planting zone provides helpful guidance on choosing beautiful plants for your Maryland garden!
FAQs about Maryland Planting Zones
What is the most common planting zone in Maryland?
Zone 7a is the predominant zone, covering central and western parts of the state, including the Baltimore region and suburbs around Washington, D.C.
What zone is Ocean City, MD?
Ocean City and the southern Eastern Shore falls into Zone 8a, the warmest zone in Maryland with milder winters.
What fruits can be grown in Maryland?
Fruits that thrive in Maryland include apples, pears, cherries, peaches, plums, strawberries, blueberries, blackberries, raspberries, and grapes. Figs and citrus can grow in protected Zone 8a areas.
What is the coldest planting zone found in Maryland?
Western mountain regions, including Garrett County, fall into Zone 6a, with average minimum winter lows between -10° to -5°F.
What zone is Baltimore, MD?
The city of Baltimore and surrounding central Maryland fall into Zone 7b, with average winter low temps between 5° to 10°F.
Should I pay attention to microclimates in Maryland?
Yes, microclimates caused by bodies of water, structures, terrain, and soil types allow for localized conditions beyond the broader USDA zone rating.
How can elevation impact planting zones?
Higher elevations typically fall into cooler zones than lower-lying areas of the same region. In western Maryland, higher mountain zones dip into 6a rather than 7a at lower elevations.
When is it safe to transplant tomatoes in Maryland?
Tomatoes can typically be transplanted into Maryland gardens 2-3 weeks after the final average spring frost, around early May in most regions.
What is the best way to use the Maryland planting zone map?
Use your zone as a starting point, choose plants rated for your zone or colder, and refine your selections based on microclimates in your specific garden area.