Maryland Plant Hardiness Zones Map And Gardening Guide

Summary

Maryland may be the 8th smallest state, but its location spans many plant hardiness zones. The hardiness of the climate ranges from 5b to 8a.¹

Maryland is divided into 2 climate ranges. Most of the state experiences a humid subtropical climate, with a small portion feeling the effects of an oceanic climate. This is due to its proximity to the Chesapeake Bay and Atlantic Ocean. The weather is overall warmer here, and the effects of a coastal climate moderate the extremes.⁵ 

In the west, with higher elevations, the state experiences a humid continental climate. This means the temperatures are cooler, more variable, and there is a higher chance of snow in the winter season.²

Maryland’s climate is moderate, but it still experiences winter weather conditions like Nor’easters. The summer season brings high precipitation, thunderstorms, and wind.

Maryland’s growing season extends from 130 to 230 days. This depends on your hardiness zone and proximity to the coast.⁴ This is a wide range of days. So, it’s important to know what zone you are in when planting in Maryland. 

Maryland is abundant in plant and wildlife biodiversity but has seen a major decline in populations over the years due to habitat loss, the use of pesticides, and the leaching of toxins from industry.^8-9

Grow a garden that promotes healthy landscapes for pollinators and other beneficial wildlife. This can help balance what habitat has already been lost in this state.^8-9

Plant suggestions include but are not limited to the following:^7,11-23

• Sweetbay Magnolia
• Common Witchhazel
• Foxglove beardtongue
• Jalapeños Peppers
• Mint
• Lavender
• Paw Paws
• Allegheny stonecrop

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Maryland Plant Hardiness Zones

USDA Hardiness Zone	Average Minimum Extreme Winter Temperature Range  Fahrenheit (°F) Celsius (°C)	Average Last Frost Date Range In Spring (Beginning Of The Growing Season)	Average First Frost Date Range In Autumn (End Of The Growing Season)
5b	-15°F to -10°F -26.1°C to – 23.3°C	Early to mid-May	Late September to early October
6a	-10°F to -5°F -23.3°C to 20.6°C	Late April to early May	Early to mid-October
6b	-5°F to 0°F -20.6°C to 17.8°C	Late April to early May	Early to mid-October
7a	0°F to 5°F -17.8°C to -15°C	Late April to early May	Early to mid-October
7b	5°F to 10°F  -15°C to -12.2°C	Early April to mid-April	Late October to early November
8a	10°F to 15°F -12.2°C to -9.4°C	Late March to early April	Early to mid-November

Maryland’s Growing Conditions

General Climate^1-5

Maryland is divided into two climate regions. 

The first is a warm-summer humid continental climate, found in the higher elevations in the west. 

It is affected by the wind from the northwest and experiences moderately cold winters with occasional snow. The summers are appropriately warm and humid. 

Most of the state has a humid subtropical climate. The humid subtropical climate is moist and warm in the summer, with lots of precipitation and high humidity. Winters are moderate and can experience frost, occasional snow, and nor’easters.

A small portion feels the effects of an oceanic climate due to its proximity to the Chesapeake Bay and Atlantic Ocean. 

The Chesapeake Bay, which divides the state in the eastern quadrant, is more than 64,000 square miles of watershed and one of the most productive estuaries in the world. This has a massive effect on the weather and overall climate near the coast.

Microclimates

USDA plant hardiness zones are an important starting point for your garden, but you’ll also need to consider microclimates. 

Microclimates are areas where specific conditions create a climate different from the climate they’re situated in. 

Buildings, fences, paved areas, or short hills and valleys can create these microclimates. 

They can be as small as a space in your backyard or as large as a city.

In other words, learn about your local conditions from local experts to see if your garden falls into a microclimate.

Extreme Weather^4,6

Unpredictable Weather 

Situated right in the middle of the East Coast, Maryland’s geography plays a large factor in its unpredictable weather patterns. Winds from all directions significantly affect the weather you’ll experience. 

The state is small in size but has a wide range of hardiness zones and climates. 

Maryland is a mountainous region with elevation gain and also experiences the Maritime effects of The Chesapeake Bay. Combined, these weather patterns impact the state and make weather relatively unpredictable, more commonly in the fall and winter. 

July through August can see an average of 1 thunderstorm every 5 days, bringing rain, wind, and even feel the effects of distant hurricanes. Tornadoes can affect some areas in Maryland from May through July, averaging around 3 a year. 

Gardening in unpredictable weather is never easy. Keep coverings for various sizes of shrubs, like burlap, on hand in case of extreme weather. Also, maintain your trees. Removing deadwood prevents it from breaking off and damaging property during storms.

Growing Season^5-6

Maryland’s growing season has quite a bit of range, depending on where you are in the state. 

The interior experiences around 130 days of growing, which is considered quite low. 

The south of Maryland and the lower Eastern Shore can experience upwards of 230 days of freeze-free weather. This is due to elevation gain, wind patterns, and proximity to the coast.  

Maryland Gardening Tips^8-11

Plant For The Birds

Maryland is known for its abundance of bird species and is considered a birders’ paradise! Birds are important in the garden as they aid in seed dispersal, balance insect populations, and contribute to a healthy ecosystem. 

The Chesapeake Bay waterways and estuaries bring in many species of birds, from shore and aquatic birds to various garden and song birds. Try growing native plants to draw in some!

Native plants have formed a symbiotic relationship with native birds and other pollinators that has been evolving for over a millennia. Planting for birds can be a fun way to create abundant ecosystems. It also helps engage and educate children on the importance of native wildlife and habitat. 

By providing food, foraging, and nesting habitat for birds, you can help build populations that may be in decline. Habitat features like bird boxes are a great way to create a nesting habitat. Make sure to do your research, as different birds require different-sized nesting boxes. 

Letting flowers go to seed, like cosmos or echinacea, provides a food source for seed-eating birds. Planting fruiting trees and shrubs does as well. 

Have a specific bird you love? Look up its food source and try adding it to your garden. 

Attract Beneficial Insects

Attracting beneficial insects can help aid in pollination, creating stronger, more fruitful crops, can be a form of biological pest control, and can create buzzing biodiversity for future generations to come.  

Many insect species are in decline due to herbicides and other chemical applications, as well as habitat loss from urbanization and agriculture. 

One awesome beneficial insect that calls Maryland home is the firefly. This bug belongs to the beetle family. 6 different species of fireflies reside in Maryland!

Why so awesome?

Fireflies are beneficial pollinators of flowers and veggies. They are also a form of biological pest management. This is with garden pests like snails and slugs when they are in their larvae life phase. 

To attract fireflies to your garden, plant native grasses for them to perch on. They use them to signal potential mates. This is a beautiful experience to witness and a fun way to teach children how cool bugs can be! 

Fireflies require trees to deposit their eggs and prefer species of pine. Try adding rotting logs as a natural habitat feature to attract food sources for their larvae. 

Large pieces of wood can be discrete and non-smelling. You can artistically place them in your garden, creating more of an organic look. As these logs break down, they add nutrients to your garden that your plants can thrive on. These logs host beneficial fungi, insects and microbes that create healthy ecosystems.

Consult With Local Professionals

Consulting with local gardening professionals allows you to benefit from their experience with your area’s conditions, the plants that do well there, and overall best practices. 

Maryland Plant Suggestions^12-24

Trees

• Sweetbay Magnolia (Magnolia virginiana)
• Tulip Poplar (Liriodendron tulipifera)
• White Ash (Fraxinus americana)

Shrubs

• Summersweet (Clethra alnifolia)
• Common Witch Hazel (Hamamelis virginiana)
• Smooth Hydrangea (Hydrangea arborescens) 

Flowers

• Foxglove beardtongue (Penstemon digitalis)
• Cardinal flower (Lobelia cardinalis)
• Turk’s Cap Lily (Lilium superbum) 

Vegetables

• Jalapeños Peppers (Capsicum annuum)
• Cucumbers (Cucumis sativus)
• Zucchini (Cucurbita pepo)

Herbs

• Mint (Mentha)
• Rosemary (Rosmarinus officinalis) 
• Chives (Allium schoenoprasum)

Spices

• Thyme (Thymus vulgaris L.)
• Sage (Salvia officinalis)
• Lavender (Lavandula)

Fruits

• Black Cherry (Prunus serotina)
• Paw Paws (Asimina triloba)
• Persimmons (Diospyros)

Succulents

• Allegheny stonecrop (Hylotelephium telephioides)
• Eastern prickly pear (Opuntia humifusa)
• Showy Stonecrop ‘Autumn Joy’ (Sedum spectabile)

Disclaimer

Any of the above can change and is not exhaustive. 

Treat anything above like a good starter guide. Then use that as a foundation as you consult with local gardeners, professionals, forecasts, guides, and organizations. 

Sources

1. “Plant Hardiness”. US Department of Agriculture. Accessed March April 15, 2024.
2. “Climate of Maryland”. Britannica. Accessed April 21, 2024. 
3. “Climate change in Maryland”. Wikipedia. January 11, 2024. Accessed April 21, 2024. 
4. “Maryland and the District of Columbia”. NOAA. Accessed April 21, 2024. 
5. “Humid subtropical climate”.  Britannica. Accessed April 21, 2024. 
6. “Maryland Weather“. Government of Maryland. Accessed April 21, 2024. 
7. Campbell, Giodona. “Unpredictable Maryland Weather”. The Student Newspaper of Paint Branch High School. January 24, 2019. Accessed April 24, 2024. 
8. LaVaute, Kelly. “Ultimate Maryland Gardening Guide”. National Wildlife Federation. December 11, 2023. Accessed April 21, 2024.  
9. Waterworth, Kristi. Saddler, Lowe. “7 Ways To Attract Fireflies In Your Yard”. March 8, 2024. Accessed April 21, 2024. 
10. “Firefly Sanctuary”. Government of Maryland. Accessed April 21, 2024. 
11. Sweetser, Robin. “Building the Ultimate Raised Bed”. Almanac. April 12, 2024. Accessed May 7, 2024. 
12. “Turk’s Cap Lily”. University of Maryland. Accessed April 21, 2024.
13. “Native Maryland Trees”. Government of Maryland. Accessed April 21, 2024. 
14. “Summersweet”. University of Maryland. June 21, 2023. Accessed April 21, 2024. 
15. “Common Witchhazel”. University of Maryland. September 12, 2023. Accessed April 21, 2024. 
16. “Smooth hydrangea”. University of Maryland. February 6, 2024. Accessed April 21, 2024. 
17. “Thyme”. Wikipedia. April 8, 2024. Accessed April 21, 2024. 
18. “Sage, Salvia officinalis”. University of Wisconsin. Accessed April 21, 2024. 
19. “Lavandula”. Wikipedia. April 1, 2024. Accessed April 21, 2024. 
20. Knighton, Diane. “Herbs for Culinary Delights: Best Varieties to Grow in Maryland Gardens”. White House Nursery. June 4, 2023. Accessed April 21, 2024. 
21. “Capsicum annuum (jalapeno)”. National Parks. Accessed April 21, 2024. 
22. “Cucumber”. Wikipedia. March 29, 2024. Accessed April 21, 2024. 
23. “Zucchini”. Britannica. March 5, 2024. Accessed April 21, 2024. 
24. “HABITAT”. Government of Maryland. Summer 2015. Accessed April 21, 2024. 
25. “Frost Dates for Waldorf, MD”. Almanac. Accessed April 21, 2024. 
26. “Frost Dates for Salisbury, MD”. Almanac. Accessed April 21, 2024. 
27. “Frost Dates for Annapolis, MD”. Almanac. Accessed April 21, 2024. 
28. “Frost Dates for Baltimore, MD”. Almanac. Accessed April 21, 2024.