Best Flowers To Plant In August In Maryland

Maryland’s mid-Atlantic position creates a sweet spot for August flowers that tolerate both heat and humidity. If you’re searching for the best flowers to plant in August in Maryland, you’re in luck—there are plenty of options that thrive even when the summer sun is at its peak. This guide covers top picks, planting tips, and care strategies to keep your garden vibrant through late summer and into fall.

August in Maryland can be tough on plants. The soil is warm, the air is thick with moisture, and afternoon storms roll through. But that doesn’t mean you have to give up on color. Many flowers actually prefer being planted in late summer, giving them time to establish roots before cooler weather arrives.

Let’s look at the best choices for your Maryland garden this August.

When we talk about the best flowers to plant in August in Maryland, we’re focusing on plants that handle heat, humidity, and occasional drought. These flowers are tough, colorful, and often bloom well into autumn. Here are the top contenders.

Marigolds

Marigolds are a classic choice for August planting. They love the heat and bloom quickly from seed or transplants. Their bright orange, yellow, and red flowers add instant cheer to any bed or container.

Plant in full sun for best blooms
Water at the base to avoid leaf diseases
Deadhead spent flowers to encourage more blooms
They repel some garden pests naturally

Marigolds are also great for filling gaps where earlier annuals have faded. They grow fast and keep going until the first hard frost.

Zinnias

Zinnias are another heat-loving flower that performs well in Maryland’s August conditions. They come in a wide range of colors and sizes, from dwarf varieties to tall cutting types. Zinnias are also excellent for attracting butterflies and pollinators.

Sow seeds directly in the garden
Space plants 6 to 18 inches apart depending on type
Water deeply once a week
Remove spent blooms to extend flowering

Zinnias are susceptible to powdery mildew in humid weather, so give them good air circulation. Avoid overhead watering to keep leaves dry.

Cosmos

Cosmos are delicate-looking but surprisingly tough. They thrive in poor soil and hot weather, making them perfect for August planting in Maryland. Their daisy-like flowers come in pink, white, and purple shades.

Plant in full sun
Don’t over-fertilize—cosmos bloom best in lean soil
Water sparingly once established
Self-sows readily for next year

Cosmos grow tall, so place them at the back of borders or in cutting gardens. They make excellent cut flowers for indoor arrangements.

Sunflowers

Sunflowers are iconic summer flowers that can still be planted in early August in Maryland. Choose fast-maturing varieties that will bloom before the first frost. Dwarf and branching types work well for late-season planting.

Plant seeds 1 inch deep in well-drained soil
Provide support for tall varieties
Water regularly during germination
Harvest seeds for birds or yourself

Sunflowers are heat-tolerant and grow quickly. They also provide food for birds and pollinators late in the season.

Celosia

Celosia, also known as cockscomb, offers unique textured blooms in red, yellow, orange, and pink. It thrives in Maryland’s August heat and adds a dramatic touch to gardens.

Plant in full sun
Keep soil consistently moist but not waterlogged
Deadhead to promote continuous blooming
Use in containers or borders

Celosia flowers last a long time, both in the garden and as cut flowers. They also dry well for winter arrangements.

Portulaca (Moss Rose)

Portulaca is a low-growing succulent that thrives in hot, dry conditions. Its bright, rose-like flowers open in the sun and close at night. This plant is perfect for rock gardens, containers, or as ground cover.

Plant in full sun and well-drained soil
Water only when soil is dry
No need to deadhead—flowers drop naturally
Great for poor soil areas

Portulaca is virtually maintenance-free once established. It blooms from summer until frost.

Salvia

Salvia, or sage, offers spikes of blue, purple, red, or white flowers that attract hummingbirds and butterflies. Many varieties are heat-tolerant and bloom repeatedly through late summer.

Plant in full sun to partial shade
Water regularly but allow soil to dry between waterings
Cut back after first bloom to encourage reblooming
Choose perennial varieties for year-after-year growth

Salvia is also deer-resistant, which is a bonus in many Maryland gardens.

Lantana

Lantana is a heat-loving perennial often grown as an annual in Maryland. Its clusters of small flowers come in multicolored combinations and bloom nonstop until frost.

Plant in full sun
Water deeply but infrequently
Prune lightly to shape
Attracts butterflies

Lantana is drought-tolerant once established. It works well in containers, hanging baskets, or as ground cover.

Verbena

Verbena produces clusters of small flowers in shades of purple, pink, red, and white. It’s a trailing plant that works well in containers or as a ground cover. It thrives in heat and blooms continuously.

Plant in full sun
Water regularly, especially in containers
Fertilize every few weeks for best blooms
Cut back leggy growth to encourage bushiness

Verbena is a favorite for pollinators and adds a soft, airy feel to gardens.

Gomphrena (Globe Amaranth)

Gomphrena produces round, clover-like flowers in purple, pink, white, and red. It’s extremely heat-tolerant and blooms from summer until frost. The flowers also dry well for crafts.

Plant in full sun
Water moderately
No deadheading needed
Good for cutting gardens

Gomphrena is low-maintenance and adds unique texture to flower beds.

Planting Tips For August In Maryland

Planting in August requires a few extra steps to ensure success. The soil is warm, which helps roots establish quickly, but heat stress can be a problem. Follow these tips for best results.

Prepare The Soil Properly

Before planting, amend your soil with compost or organic matter. This improves drainage and provides nutrients. Maryland’s clay soils benefit from added organic material to prevent waterlogging.

Test soil pH if possible—most flowers prefer 6.0 to 7.0
Remove weeds and debris
Loosen soil to at least 6 inches deep
Mix in a slow-release fertilizer

Water Wisely

August heat means plants need consistent moisture, especially in the first few weeks after planting. Water deeply in the morning to reduce evaporation and prevent fungal diseases.

Water at the base of plants, not overhead
Use soaker hoses or drip irrigation
Mulch around plants to retain moisture
Check soil moisture daily during heat waves

Provide Shade If Needed

Some flowers benefit from afternoon shade during the hottest part of the day. If you’re planting in a south-facing bed, consider using shade cloth or planting near taller plants for protection.

Use temporary shade cloth for new transplants
Plant heat-sensitive flowers on the east side of buildings
Group plants to create natural shade

Mulch To Protect Roots

A 2- to 3-inch layer of mulch keeps soil cool, retains moisture, and suppresses weeds. Use organic mulch like shredded bark, straw, or grass clippings.

Keep mulch away from plant stems
Replenish mulch as needed
Avoid using fresh wood chips that can tie up nitrogen

Caring For August-Planted Flowers

Once your flowers are in the ground, ongoing care is key to keeping them healthy through the rest of summer and into fall.

Fertilize Lightly

Most flowers benefit from a light application of balanced fertilizer every 4 to 6 weeks. Avoid high-nitrogen fertilizers that promote leaf growth at the expense of blooms.

Use a 10-10-10 or 5-10-5 formula
Apply according to package directions
Water after fertilizing

Deadhead Regularly

Removing spent flowers encourages plants to produce more blooms. This is especially important for marigolds, zinnias, and cosmos.

Pinch or cut off faded flowers
Remove entire flower stem for best results
Do this weekly during peak bloom

Watch For Pests And Diseases

August humidity can lead to fungal issues like powdery mildew and botrytis. Keep an eye out for common pests like aphids, spider mites, and Japanese beetles.

Inspect plants regularly
Use insecticidal soap for soft-bodied pests
Remove affected leaves promptly
Improve air circulation by spacing plants properly

Prepare For Fall

As summer winds down, some flowers will continue blooming into September and October. Others may need to be replaced with cool-season annuals like pansies or mums.

Cut back spent plants after frost
Collect seeds from annuals for next year
Add compost to beds for fall planting

Regional Considerations For Maryland Gardens

Maryland spans multiple USDA hardiness zones, from 5b in the mountains to 8a on the Eastern Shore. This affects what you can plant in August and how well it will perform.

Western Maryland (Zones 5-6)

In the western part of the state, summers are slightly cooler, and frost comes earlier. Choose fast-maturing flowers that can bloom before mid-October.

Plant marigolds, zinnias, and cosmos from seed
Use transplants for slower-growing flowers
Be ready to protect plants from early frost

Central Maryland (Zones 6-7)

Central Maryland, including Baltimore and the suburbs, has a longer growing season. Most August-planted flowers will bloom until the first frost in late October or early November.

Plant a mix of annuals and perennials
Water consistently during dry spells
Enjoy blooms through September

Eastern Shore And Southern Maryland (Zones 7-8)

These areas have milder winters and longer summers. You can plant flowers later in August and still expect good results. Some perennials may even overwinter.

Try lantana, verbena, and gomphrena
Plant heat-tolerant varieties
Consider adding fall-blooming perennials

Frequently Asked Questions

Can I plant perennials in August in Maryland?

Yes, but choose heat-tolerant varieties and water them well. Perennials like black-eyed Susans, coneflowers, and sedum can be planted in August if given proper care. They’ll establish roots before winter.

What flowers bloom in August in Maryland?

Many flowers bloom in August, including zinnias, marigolds, sunflowers, cosmos, and lantana. These flowers thrive in the heat and continue blooming into fall.

Is it too late to plant flowers in August?

No, it’s not too late. August is an excellent time to plant flowers in Maryland because the soil is warm and roots establish quickly. Just choose heat-tolerant varieties and water consistently.

What annuals can I plant in August in Maryland?

Annuals like marigolds, zinnias, cosmos, celosia, portulaca, and verbena are great choices. They bloom quickly and keep going until frost.

How often should I water flowers planted in August?

Water newly planted flowers daily for the first week, then gradually reduce to once or twice a week. Adjust based on rainfall and temperature. Deep watering is better than frequent light watering.

Final Thoughts On August Planting

Planting flowers in August in Maryland is a smart way to extend your garden’s color into fall. The key is choosing the right plants and giving them proper care during the hottest weeks. With marigolds, zinnias, cosmos, and other heat-loving flowers, you can enjoy a vibrant garden well into October.

Don’t let the summer heat discourage you. August is a great time to get your hands dirty and add some beauty to your yard. Just remember to water wisely, mulch well, and keep an eye out for pests. Your garden will thank you with weeks of blooms.

So go ahead—pick up some seeds or transplants this weekend. Your Maryland garden can still shine this August.