What Flower Seeds to Plant in August 2026: U.S. Guide for Fall and Spring Blooms

August may feel like the end of the planting season, but it can be the beginning of another colorful chapter in your garden.

Depending on your climate, August can be used to:

Plant fast-growing annuals for late-season flowers
Start pansies and other cool-season flowers
Sow biennials and perennials for next year
Prepare seeds for fall planting in mild-winter regions
Replace tired summer plants in containers
Establish flowers that support late-season pollinators

The important question is not simply, “Can I plant flower seeds in August?” It is, “Which flowers have enough time to grow in my location?”

This guide will help you choose flower seeds based on your average first frost, summer temperatures, and desired bloom season.

Ready to plan your late-summer flower garden? Browse flower seeds at Urban Garden Seed and check each variety’s current availability and planting requirements.

Can You Plant Flower Seeds in August?

Yes, but the best choices depend on where you live.

Gardeners in northern states may have only six to eight weeks before frost. Their best August projects often include starting pansies, sowing cold-hardy perennials, or preparing for dormant fall sowing.

Gardeners in the middle of the country may still have time for fast annuals, especially during early August.

Southern and mild-winter gardeners can begin planning cool-season flower gardens that grow during fall, winter, or early spring.

Even conditions within one state can vary. UF/IFAS publishes separate August flower recommendations for North, Central, and South Florida, demonstrating why local climate matters more than a nationwide calendar date. See the UF/IFAS August flower guide.

Start With Your Average First Frost Date

Before planting, find your area’s average first fall frost date through a local Cooperative Extension office or reliable weather resource.

Then count the number of days between your August planting date and the expected frost.

Use this general framework:

Remaining frost-free period	Best August strategy
Fewer than 45 days	Start cool-season flowers in containers or sow perennials for next year
45–60 days	Try very fast annuals and begin pansies or perennials
60–90 days	Plant fast annuals, cool-season flowers and selected perennials
More than 90 days	Broader selection of annuals and cool-season flowers
Frost-free or mild winter	Prepare a fall and winter flower garden

An average frost date is not a guarantee. Weather can change from year to year, so include extra time instead of assuming every flower will bloom on the earliest possible date.

Quick August Flower-Seed Planting Chart

Flower	August planting method	Likely goal	Important condition
Zinnias	Direct sow	Late-summer and fall blooms	Enough warm weather before frost
Marigolds	Direct sow	Fast fall color	Warm soil and adequate time
Pansies and violas	Start in trays	Fall or spring flowers	Protect germination trays from heat
Calendula	Direct sow or start in pots	Cool-season blooms	Wait for extreme heat to ease
Sweet alyssum	Direct sow or start in containers	Cool-season edging	Best when temperatures moderate
Snapdragons	Start in trays	Cool-season transplanting	Small seed needs careful moisture
Hollyhocks	Sow in flats or nursery bed	Flowers in a future season	Allow plants time to establish
Delphiniums	Start in pots or flats	Future perennial flowers	Follow variety-specific requirements
Coneflowers	Sow in pots or prepared bed	Future perennial display	Some varieties benefit from cold exposure
Yarrow	Sow in trays	Future drought-tolerant flowers	Avoid burying small seeds deeply
Salvia	Start in pots or flats	Fall transplanting or next year	Requirements vary by species
California poppies	Purchase and prepare for fall sowing	Spring flowers	Usually wait until weather cools
Sweet peas	Purchase for fall or early-spring sowing	Cool-season flowers	Do not plant during extreme heat

Always follow the directions for the specific species and variety. Not every flower sharing a common name has identical germination requirements.

1. Pansies and Violas

Pansies are among the strongest flower-seed choices for August because they prefer cooler growing conditions after establishment.

Start the seeds in trays or small pots where you can control temperature and moisture. Keep them away from intense afternoon sun while germinating.

Utah State University Extension recommends planting pansy seeds during July or August when gardeners want plants to bloom as early as possible the following spring. Read its pansy-growing guidance.

North Carolina Cooperative Extension also recommends sowing pansy seed in flats during August for later landscape planting.

Pansies work especially well in:

Window boxes
Patio containers
Front-yard borders
Fall displays
Cool-season pollinator gardens

Shop multicolor pansy seeds and verify the current variety details before planting.

2. Zinnias

Zinnias are fast-growing warm-season annuals that can provide late color when enough frost-free weather remains.

Consider an August sowing when:

Your first frost is still approximately two months away
The soil remains warm
The planting area receives full sun
You can water the seedbed consistently
You select a relatively fast-flowering variety

Direct sow zinnias into prepared soil and follow the packet’s planting-depth and spacing directions. Keep the seedbed consistently moist during germination.

Zinnias are a better August choice in regions with a long fall than in northern locations where frost may arrive early.

3. Marigolds

Marigolds can germinate and grow quickly in warm soil. Dwarf or compact varieties generally reach flowering size sooner than very tall types.

Use marigolds to fill:

Empty vegetable-garden edges
Sunny containers
Bare spaces left by finished annuals
Walkway borders
Small pollinator beds

Late-sown marigolds still need sufficient time before frost. Check the variety’s expected maturity and flowering period before ordering.

4. Calendula

Calendula is a cool-season annual that can grow during fall or winter in suitable climates.

In regions with hot August weather, start seeds in a protected location or wait until temperatures begin moderating. Gardeners in mild-winter areas can use calendula in fall beds and containers.

Calendula may not tolerate every winter, so check its suitability for your location.

5. Sweet Alyssum

Sweet alyssum creates a low-growing carpet of small flowers suitable for borders, containers, and spaces between taller plants.

It performs best in cooler conditions. If August remains extremely hot, start the seeds in a protected area or wait until early fall.

Use sweet alyssum around:

Pansy containers
Raised-bed edges
Garden paths
Window boxes
Pollinator plantings

6. Snapdragons

Snapdragons are popular cool-season flowers in many parts of the United States. Late summer can be used to start seeds for transplanting after temperatures become more favorable.

Because snapdragon seeds are tiny:

Use a fine, sterile seed-starting medium
Avoid burying them too deeply
Water gently
Provide bright light after germination
Maintain airflow around the seedlings
Harden them off before outdoor transplanting

Timing varies considerably between northern and southern climates. Gardeners with severe winters may grow them for spring, while mild-winter gardeners may use them in fall and winter displays.

7. Hollyhocks

Hollyhocks are biennials or short-lived perennials that often flower after developing an established plant during an earlier season.

August sowing is not necessarily intended to produce immediate flowers. The goal is to create healthy young plants capable of blooming later.

North Carolina Cooperative Extension lists hollyhock, delphinium, and Stokesia among the perennials that can be sown during August for healthy plants the following spring. View its August garden calendar.

8. Delphiniums

Delphiniums produce impressive vertical flower spikes, but they require more patience than zinnias or marigolds.

Start seeds in pots or flats, following the instructions for your specific variety. Some delphinium seeds have special temperature requirements and may not germinate well in excessive heat.

Protect young seedlings from harsh afternoon sun and transplant only when conditions are suitable.

9. Coneflowers

Coneflowers can be valuable additions to perennial and pollinator gardens. August sowing may help establish plants for future seasons rather than immediate blooms.

Different coneflower species and varieties have different dormancy requirements. Some may germinate without treatment, while others benefit from a period of moist cold stratification.

Check the seed packet before planting.

10. Yarrow

Yarrow is a useful perennial for sunny, well-drained landscapes. Established plants can tolerate relatively dry conditions, but seeds and new seedlings need consistent moisture.

Its small seeds should not be buried deeply. Start them in trays or pots if outdoor August weather is too hot or unpredictable.

UC Master Gardeners of Tuolumne County recommends sowing perennials such as yarrow, coneflower, thrift, and salvia in flats or pots during August for later transplanting. See its August gardening recommendations.

11. Salvia

The name “salvia” includes annual and perennial species with different growing requirements.

Some salvias can be started during August for fall transplanting or future flowering. Verify:

Whether the variety is annual or perennial
Its hardiness zone
Whether it requires light to germinate
Whether cold stratification is necessary
Its recommended transplanting season

Avoid applying one set of directions to every Salvia species.

Seeds to Buy in August but Plant Later

August is also an excellent month to purchase seeds for fall sowing, even when conditions are still too hot for immediate planting.

Depending on your climate, these may include:

California poppies
Bachelor’s buttons
Sweet peas
Larkspur
Annual poppies
Cool-season wildflowers
Selected native perennials

Many cool-season flowers germinate better after soil temperatures fall. Ordering during August helps you prepare the bed and plant at the correct local time.

August Flower Planting by Climate

Short-Season and Northern Gardens

If frost typically arrives before the middle of October:

Start pansies in protected trays.
Sow suitable perennials and biennials for future seasons.
Use containers that can be protected from early cold.
Only plant fast annuals when their expected flowering time fits your remaining season.
Begin planning dormant fall and winter sowing.

Moderate-Season Gardens

If frost generally arrives between mid-October and mid-November:

Direct sow fast zinnias or marigolds early in August.
Start pansies and snapdragons in trays.
Sow perennials in nursery containers.
Prepare beds for cool-season flowers.
Stop planting warm-season annuals when insufficient time remains.

Long-Season Southern Gardens

If frost usually arrives after mid-November:

Plant fast warm-season annuals where summer heat remains suitable.
Begin cool-season flower seeds in protected trays.
Wait for extreme soil heat to moderate before planting calendula or alyssum.
Prepare fall containers and flower beds.
Check local Extension calendars for precise recommendations.

Frost-Free and Mild-Winter Gardens

In warm coastal, desert, subtropical, and tropical areas:

Treat August as a transition and planning month.
Start cool-season flowers under shade or indoors.
Continue suitable heat-tolerant annuals.
Move seedlings outdoors after temperatures become favorable.
Use regional guidance because humidity, rainfall, and nighttime temperatures vary widely.

How to Start Flower Seeds During August Heat

Sow During the Cooler Part of the Day

Plant early in the morning or during the evening. Avoid working with delicate seeds when containers and soil are extremely hot.

Moisten the Soil Before Planting

Dry summer soil can repel water. Moisten the growing medium before sowing so seeds are not washed away afterward.

Provide Temporary Shade

Seed trays may need protection from intense afternoon sun. A bright location with temporary shade can prevent the growing medium from overheating.

Check Moisture More Than Once Daily

Small containers can dry rapidly in August. Keep the medium consistently moist without leaving it waterlogged.

Do Not Plant Seeds Too Deeply

Small flower seeds frequently require only a very light covering. Follow each variety’s directions instead of using one planting depth for every flower.

Protect Seedlings From Storms

Summer downpours can wash small seeds from the soil or flatten new seedlings. Move trays to a protected location when severe weather is expected.

Harden Off Indoor-Grown Seedlings

Gradually expose seedlings to outdoor sun, wind, and temperature changes before transplanting them permanently.

Common August Flower-Planting Mistakes

Ignoring the First Frost Date

A flower may germinate quickly but still require several weeks before blooming. Confirm that enough growing time remains.

Choosing Only Heat-Loving Flowers

August is also the time to prepare cool-season flowers and perennials for future blooms.

Planting Cool-Season Seeds in Hot Soil

Pansies, alyssum, and similar flowers may struggle when the soil remains extremely hot. Use a protected seed-starting area or delay planting.

Allowing the Seedbed to Dry

The top layer of soil dries quickly during late summer. Once germination begins, a severe dry period can kill the developing seedling.

Expecting Every August Planting to Bloom This Year

Perennials and biennials may not flower until the following spring, summer, or even later.

Relying Only on USDA Hardiness Zones

Hardiness zones describe average winter minimum temperatures. They do not tell you your exact first frost date, summer soil temperature, rainfall, or remaining growing days.

Frequently Asked Questions

Is August too late to plant flowers?

Not necessarily. Fast annuals may still bloom where enough warm weather remains, while pansies, biennials, and perennials can be started for later seasons.

Which flowers grow fastest from an August sowing?

Zinnias and marigolds are among the faster warm-season choices. Their success depends on the variety and the time remaining before frost.

Can I plant wildflower seeds in August?

Possibly, but many wildflower mixtures perform better when sown later in fall, during winter dormancy, or in spring. Check the species in the mixture and use local recommendations.

Can I plant pansy seeds in August?

Yes. July and August are commonly recommended for starting pansies intended for cool-season or early-spring displays. Protect germinating seeds from excessive heat.

What flowers can I start for next year?

Depending on your location and variety, possibilities include hollyhocks, delphiniums, coneflowers, yarrow, Salvia, Stokesia, and other hardy perennials.

Should I start August flower seeds indoors?

Starting seeds in trays is helpful when outdoor soil is excessively hot, heavy rain is common, or seedlings need protection before fall transplanting.