When to Plant Sunflower Seeds in Maryland: Frost-Free Dates by Variety

Planting sunflower seeds in Maryland after the last frost date—typically late April to early June—sets them up for a towering summer display.

Maryland’s warm summers and long growing season make it an ideal place for sunflowers—but planting at the wrong time can leave you with wilted blooms instead of towering beauty. Timing your sunflower seeds correctly ensures vibrant flowers, strong stems, and a bountiful harvest (or stunning cut arrangements).

In USDA zones 7a-7b, where Maryland falls, the key is waiting until the soil warms and the danger of frost has passed. That usually means mid-April for coastal areas and early May inland, but don’t rush—cold soil slows germination, and young seedlings won’t survive a late freeze.

Below, I’ll break down the exact frost-free dates by region, the best sunflower varieties for Maryland gardens, and how to extend your growing season for longer blooms—so you can enjoy those golden faces from July through October.

Maryland sunflower planting calendar: frost-free dates by region

Maryland’s diverse climate—from the cooler Eastern Shore to the warmer Western Mountains—means sunflower planting times vary dramatically. Getting your seeds in the ground at the right moment ensures strong germination and vibrant blooms before Maryland’s first frost in mid-November.

I’ve broken down the best planting windows for each region, including frost-free dates and ideal varieties.

For most of Maryland, the last frost date falls between April 15 and May 1, but coastal areas like Eastern Shore can experience late frosts as late as May 10.

Inland areas like Baltimore and Frederick typically warm up faster, giving you a 2-week head start on planting. Always check your local USDA Zone (7a-7b) for precision.

Here’s how to match your planting schedule to Maryland’s three key regions—plus tips for extending your growing season in unpredictable years.

If you’re in Western Maryland, where nights stay chilly longer, opt for heat-tolerant varieties like 'Russian Giant' to avoid bolting. For coastal areas, prioritize dwarf varieties like 'Teddy Bear' to prevent wind damage. Always plant seeds 1 inch deep and 6 inches apart for optimal airflow and growth.

For gardeners in Baltimore’s urban heat islands, you can push planting dates slightly earlier—mid-April—thanks to microclimates that warm faster. Monitor soil temperatures with a soil thermometer; aim for 60°F+ for consistent germination.

If your soil is still cold, use black plastic mulch to warm it up 2–3 weeks faster.

Late-season plantings in June or early July are still possible for short-day varieties like 'Autumn Beauty,' which thrive in Maryland’s summer heat. These varieties bloom later but produce stunning multi-colored flowers perfect for fall arrangements. Just be sure to plant them 8–10 weeks before your first frost to ensure maturity.

Pro tip: Use row covers for early plantings to protect seedlings from unexpected late frosts, which can still hit as late as May 15 in some years.

Remove covers once plants reach 6 inches tall to prevent overheating. For container growers, place pots in wheeled trays to move them indoors if frost threatens.

Remember, sunflowers are fast growers—some varieties reach 10 feet in 80 days! But rushing planting can lead to weak stems or bolt before flowering.

Stagger plantings every 2 weeks for a continuous display from July through October. This works especially well for cut flower gardens or seed harvesting.

Finally, keep an eye on your local Almanac’s frost predictions—they’re updated annually. Maryland’s climate is shifting, and frost dates can vary by 5–7 days each year. Adjust your schedule accordingly, and you’ll enjoy sunflowers that tower over your fence all season long!

Best sunflower varieties for Maryland gardens and their planting times

Maryland’s diverse sunflower varieties thrive when planted at the right time, and choosing the perfect type depends on your space and goals. Whether you want dwarf sunflowers for containers or giant varieties for dramatic height, timing is everything.

Most Maryland gardeners plant between mid-April and early June, but some late-season varieties can handle July sowings too.

For bountiful harvests, I recommend starting with 'Autumn Beauty' or 'Mammoth Russian'—both are Maryland favorites. However, if you’re short on space, dwarf varieties like 'Teddy Bear' or 'Sunspot' are perfect for patios and small gardens.

Each variety has unique days to maturity, so let’s break down the best options for your garden.

If you’re growing 'Mammoth Russian' sunflowers, I recommend planting them in late April to early June—they need a long, warm season to reach their full 10-14 foot height.

These giants are perfect for seed harvests or creating a stunning focal point in your garden, but they require sturdy stakes to prevent toppling in Maryland’s summer winds.

For quick blooms, dwarf varieties like 'Teddy Bear' are ideal. They mature in just 50-55 days, making them perfect for May or June plantings if you want summer color without waiting. These are also great for container gardening or adding height to flower beds without overwhelming your space.

Don’t forget about succession planting—if you want sunflowers all summer, try planting early varieties in April and late varieties in June. This ensures continuous blooms from July through October, giving pollinators like bees and butterflies a steady food source.

Just be sure to space them properly—giant varieties need at least 18 inches apart, while dwarfs can handle 6-12 inches.

For maximum success, I always test my soil’s pH level before planting—sunflowers prefer 6.0 to 7.5. Amending with compost ensures they get the nutrients they need for strong stems and vibrant blooms.

With the right variety and timing, your Maryland garden can be a golden paradise by summer! 🌻