Best Flowers To Plant In August In Pennsylvania

Pennsylvania’s transition from hot summer to cooler evenings favors certain hardy bloomers. If you’re looking for the best flowers to plant in August in Pennsylvania, you’ve come to the right place. August might seem late for planting, but it’s actually a prime window for many flowers that thrive in the Keystone State’s unique climate. Whether you’re a seasoned gardener or just starting out, this guide will help you choose the right blooms for a vibrant late-summer and fall display.

Planting in August gives your flowers a head start. The soil is warm, which encourages root growth. Plus, the milder weather of early fall reduces stress on new plants. You’ll enjoy color well into October and even November with the right choices.

Let’s get straight to the list. These flowers are proven performers for Pennsylvania’s August planting season. They handle the heat and transition smoothly into cooler nights.

Chrysanthemums: The Fall Classic

Mums are the undisputed kings of autumn color. They come in a huge range of shades, from deep burgundy to bright yellow. Plant them in August for strong root development before the first frost.

Choose compact, bushy plants with many buds.
Water deeply after planting to settle the roots.
Deadhead spent blooms to encourage more flowers.
Mulch around the base to retain moisture.

Pansies: Cool-Weather Champions

Pansies love Pennsylvania’s cooler August evenings. They’ll bloom through fall and often survive mild winters to bloom again in spring. Plant them in well-drained soil with partial sun.

Space pansies about 6-8 inches apart.
Fertilize with a balanced, slow-release formula.
Water regularly, especially during dry spells.
Remove faded flowers to keep them blooming.

Ornamental Kale And Cabbage

These aren’t your typical flowers, but their colorful foliage adds stunning texture. They thrive in cool weather and look great from September through November. Plant them in full sun for the best color.

Set plants 12-18 inches apart for full growth.
Water at the base to avoid leaf rot.
They get more vibrant after the first light frost.
Pair them with mums for a striking display.

Snapdragons: Tall And Graceful

Snapdragons add height and drama to any garden. They prefer cooler temperatures and will bloom until a hard freeze. Plant them in a spot with good air circulation.

Choose dwarf varieties for borders, tall ones for backdrops.
Pinch off the top of young plants for bushier growth.
Water deeply once a week, more if it’s hot.
Stake tall varieties to prevent flopping.

Dianthus: Fragrant And Hardy

Dianthus, also called pinks, offer spicy-scented flowers in pink, red, and white. They’re tough plants that handle Pennsylvania’s variable weather. Plant them in full sun for the best blooms.

Space plants 8-12 inches apart.
Cut back after the first flush of blooms for a second show.
They’re deer-resistant, which is a bonus.
Use them in rock gardens or borders.

Black-Eyed Susans: Native Beauty

These cheerful yellow flowers are Pennsylvania natives. They’re drought-tolerant and attract pollinators. Plant them in August for a strong start before winter.

Choose a sunny location with well-drained soil.
Water regularly until established.
Deadhead to extend blooming into fall.
They self-seed, so you’ll get more next year.

Asters: Late-Season Stars

Asters burst into bloom in late summer and early fall. They come in purple, blue, pink, and white. Plant them in full sun for the most flowers.

Space plants 12-24 inches apart depending on variety.
Water during dry periods to prevent mildew.
Cut back by half in early summer for compact growth.
They’re excellent for cutting gardens.

Sedum: Low-Maintenance Succulents

Sedum, or stonecrop, is perfect for lazy gardeners. It thrives in poor soil and full sun. The flowers attract butterflies and bees.

Plant in well-drained soil; they hate wet feet.
Space 12-18 inches apart for ground covers.
Water only during extended droughts.
Leave seed heads for winter interest.

Marigolds: Reliable And Bright

Marigolds are workhorses in the garden. They bloom nonstop from planting until frost. They also repel some pests, making them great companions for vegetables.

Plant in full sun for the most flowers.
Deadhead regularly to keep them blooming.
Water at the base to prevent fungal issues.
Use French marigolds for borders, African for height.

Cosmos: Easy And Airy

Cosmos are tall, delicate-looking flowers that are surprisingly tough. They thrive in poor soil and bloom until frost. Plant them in a sunny spot with good drainage.

Sow seeds directly in the garden in early August.
Thin seedlings to 12-18 inches apart.
Water sparingly; they prefer dry conditions.
Cut flowers for bouquets to encourage more blooms.

Preparing Your Garden For August Planting

Before you plant, take a few steps to give your flowers the best start. Pennsylvania soil can vary from clay to sandy loam. Knowing your soil type helps you choose the right plants and amendments.

Test Your Soil

Get a simple soil test kit from a garden center. Test for pH and nutrient levels. Most flowers prefer a pH between 6.0 and 7.0. Add lime to raise pH or sulfur to lower it.

Amend The Soil

Mix in 2-3 inches of compost or well-rotted manure. This improves drainage and adds nutrients. For clay soil, add sand or perlite to loosen it. For sandy soil, add organic matter to hold moisture.

Watering Strategy

August can be hot and dry in Pennsylvania. Water new plants deeply right after planting. Then water every 2-3 days for the first two weeks. After that, water once a week unless it’s very dry.

Water in the morning to reduce evaporation.
Use a soaker hose or drip irrigation for efficiency.
Avoid overhead watering to prevent leaf diseases.
Mulch with 2-3 inches of bark or straw to retain moisture.

Choose The Right Location

Most August-planted flowers need full sun, meaning at least 6 hours of direct sunlight daily. Check your garden’s sun patterns before planting. Partial shade works for pansies and some asters.

Caring For Your August-Planted Flowers

Once your flowers are in the ground, a little care goes a long way. Pennsylvania’s weather can be unpredictable, so stay attentive.

Fertilizing

Use a balanced fertilizer like 10-10-10 at planting time. Follow up with a liquid fertilizer every 2-3 weeks until mid-September. Stop fertilizing after that to let plants harden off for winter.

Deadheading And Pruning

Remove spent flowers regularly to encourage more blooms. For plants like snapdragons, cut back the main stem after the first flush. This promotes side shoots and a second wave of flowers.

Pest And Disease Control

Watch for common pests like aphids, slugs, and spider mites. Use insecticidal soap for aphids. Handpick slugs at night. Ensure good air circulation to prevent powdery mildew.

Check plants weekly for signs of trouble.
Remove diseased leaves immediately.
Use neem oil as a natural fungicide.
Encourage beneficial insects like ladybugs.

Preparing For Frost

Pennsylvania’s first frost can come as early as late September in the north, or mid-October in the south. Have row covers or old sheets ready to protect tender plants. Hardy flowers like mums and pansies can handle light frosts.

Regional Considerations For Pennsylvania

Pennsylvania spans USDA hardiness zones 5a to 7b. Your location affects which flowers thrive. Here’s a breakdown by region.

Eastern Pennsylvania (Philadelphia, Allentown)

Zone 6b-7b. Milder winters and longer growing season. You can plant later into August. Try heat-tolerant varieties like marigolds and cosmos.

Central Pennsylvania (Harrisburg, State College)

Zone 6a-6b. Moderate climate. Focus on flowers that handle both heat and cool nights. Asters and sedum work well here.

Western Pennsylvania (Pittsburgh, Erie)

Zone 5b-6a. Cooler summers and earlier frosts. Plant by mid-August for best results. Pansies and ornamental kale are excellent choices.

Northern Pennsylvania (Scranton, Williamsport)

Zone 5a-5b. Short growing season. Choose fast-growing flowers like snapdragons and dianthus. Protect from early frosts.

Companion Planting Ideas

Pairing flowers with vegetables or herbs can boost your garden’s health. Here are some combinations that work well in Pennsylvania.

Marigolds With Tomatoes

Marigolds repel nematodes and whiteflies. Plant them around tomato plants for natural pest control. They also add color to the vegetable garden.

Nasturtiums With Cucumbers

Nasturtiums attract aphids away from cucumbers. They’re edible too, with peppery leaves and flowers. Plant them in August for fall harvests.

Borage With Strawberries

Borage attracts pollinators and improves strawberry flavor. Its blue flowers are beautiful. Plant it in August for late-season blooms.

Common Mistakes To Avoid

Even experienced gardeners make errors. Here are pitfalls to sidestep when planting in August.

Planting too late in the month, especially in northern zones.
Overwatering, which leads to root rot.
Skipping soil preparation, especially in clay-heavy areas.
Choosing shade-loving plants for sunny spots.
Ignoring frost dates and not protecting tender plants.
Planting too deep, which suffocates roots.
Using too much fertilizer, which burns roots.
Forgetting to harden off nursery plants if they were grown indoors.

Frequently Asked Questions

Can I plant perennials in August in Pennsylvania?

Yes, many perennials like black-eyed Susans, asters, and sedum do well when planted in August. They have time to establish roots before winter. Water them regularly until the ground freezes.

What flowers bloom in August in Pennsylvania?

Many flowers bloom in August if planted earlier. For August planting, you’ll get blooms from mums, pansies, and snapdragons starting in September. Cosmos and marigolds bloom quickly from seed.

Is it too late to plant flowers in August in Pennsylvania?

No, it’s not too late. August is ideal for fall-blooming flowers. You’ll miss the peak summer heat, and plants establish well in warm soil. Just choose the right varieties for your zone.

Should I water flowers every day in August?

No, daily watering can cause root rot. Water deeply 2-3 times a week for new plants. Established plants need once a week unless it’s very hot and dry. Check soil moisture before watering.

What are the best low-maintenance flowers for August planting in Pennsylvania?

Sedum, black-eyed Susans, and marigolds are very low-maintenance. They tolerate poor soil, drought, and neglect. Pansies also require minimal care once established.

Final Tips For Success

Planting flowers in August in Pennsylvania is rewarding. You get to enjoy color when many gardens are fading. Follow these tips for the best results.

Shop for plants at local nurseries for varieties adapted to your area.
Plant on a cloudy day or in the evening to reduce transplant shock.
Water with a gentle spray to avoid disturbing soil.
Keep a garden journal to track what works and what doesn’t.
Don’t be afraid to experiment with new varieties each year.
Enjoy the process and share your blooms with neighbors.

With the right choices and care, your Pennsylvania garden can be a showstopper from August through November. Start planning today, and you’ll be rewarded with vibrant color that lasts well into the fall season. Happy planting!