Seeds to Direct Sow 4-6 Weeks Before Your Last Frost

Learn which seeds to direct sow 4-6 weeks before your last frost date, including leafy greens, brassicas, and herbs, plus planting tips.

As spring continues to unfold and the soil begins to warm, even more crops can be planted directly into the garden.

The 4-6 weeks before your average last frost date is a key transition period for direct sowing. During this time, the soil is often workable, daytime temperatures are milder, and many cool-season vegetables can be planted outdoors with minimal protection.

In this guide, you’ll learn which seeds to direct sow during this window and how to time planting for healthy, productive growth.

Start With Your Average Last Frost Date

Your average last frost date is the foundation of your planting schedule. This date helps you determine when it’s generally safe to plant seeds outdoors without risking damage from hard freezes. To find yours, enter your ZIP code at PlantMaps.com or Garden.org, then count backward to determine when to direct sow.

For help building a complete planting plan, see: How to Create a Seed Starting Schedule Based on Your Last Frost Date.

The last frost date is a good guideline for when to plant, but you should also check your soil. Direct sowing works well when the soil has dried out and is easy to work with. If the soil is still frozen or very wet, it’s best to wait.

To test your soil, take a handful and squeeze it in your hand:

• If it crumbles easily when you tap it, the soil is ready to plant.
• If it holds together in a wet clump, wait a bit longer for it to dry out.

While frost is still possible during this window, many of the crops listed here tolerate cool temperatures once established. Focus on soil conditions as much as calendar dates.

Why These Seeds Are Direct Sown 4-6 Weeks Before Frost

Crops planted during this time prefer cool to mild temperatures and can handle light frosts.

Seeds direct sown 4-6 weeks before frost:

• Germinate reliably in cool soil.
• Grow steadily without bolting.
• Perform better when planted early rather than in warm weather.

Planting during this window helps crops establish strong growth before warmer temperatures slow development or trigger bolting.

Seeds to Direct Sow 4-6 Weeks Before Your Last Frost Date

The following crops can be planted directly into the garden once the soil has drained and warmed to about 50°F. Always check your seed packet for specific planting depth, spacing, and timing recommendations.

Leafy Greens to Direct Sow

Leafy greens thrive in cool spring weather and benefit from early planting before temperatures rise. Direct sowing allows these fast-growing crops to establish quickly and produce tender leaves while conditions are ideal. Many leafy greens can also be succession planted for extended harvests.

Arugula (Rocket)

Arugula, also known as rocket, thrives in cool weather and germinates quickly in early spring. Direct sowing produces tender, flavorful leaves before heat causes plants to bolt. For continuous harvests, sow small amounts every few weeks during cool conditions.

Lettuce

Lettuce grows quickly and prefers cool, consistent temperatures. Direct sowing now produces tender leaves and compact heads before heat stress causes bitterness or bolting. Succession planting every couple of weeks helps maintain a steady supply throughout spring.

Swiss Chard

Swiss chard is cold-tolerant and easy to grow from seed. Direct sowing in early spring allows plants to establish strong roots and produce early harvests. Unlike many greens, Swiss chard continues producing well as temperatures warm, making it a reliable bridge between spring and summer.

Mustard Greens

Mustard greens grow rapidly and develop their best flavor in cool weather. Early direct sowing encourages lush leaf growth before rising temperatures trigger bolting. These greens are ideal for quick spring harvests and can be succession planted for ongoing yields.

Brassicas to Direct Sow

Many brassicas perform well when direct sown during cool spring conditions. Early planting supports steady growth and helps plants mature before summer heat or pest pressure increases.

Cabbage

Cabbage prefers cool temperatures and consistent growth. Direct sowing early allows plants to establish strong roots and develop firm heads before hot weather slows growth or affects quality. Thin seedlings promptly to give plants adequate space.

Brussels Sprouts

Brussels sprouts benefit from an early start, even when direct sown. Cool spring weather supports strong early growth and healthy stalk development. Although they mature later in the season, early establishment sets the foundation for better yields.

Kohlrabi

Kohlrabi matures quickly and develops the best texture when grown in cool conditions. Direct sowing early encourages tender, crisp bulbs before heat causes toughness. Harvest promptly once bulbs reach size for best flavor.

Herbs to Direct Sow

Some herbs prefer cool soil and steady spring temperatures and are best sown directly in the garden rather than transplanted. These herbs establish long or delicate root systems and benefit from early planting before summer heat arrives.

Chervil

Chervil is a delicate culinary herb that thrives in cool spring conditions. It prefers moist soil and partial shade and will bolt quickly once temperatures rise. Direct sow chervil early so it can grow and be harvested before warm weather arrives.

Dill

Dill germinates easily in cool soil and is well suited to direct sowing in early spring. It develops a long taproot and does not transplant well, making direct sowing the best option for healthy growth. Planting dill early encourages steady leaf production before warm weather triggers flowering and seed set.

Herb Fennel

Herb fennel is grown for its feathery leaves and seeds. It develops a long taproot and does not transplant well, making direct sowing the best option.

Summer Savory

Summer savory is an annual herb with a mild, peppery flavor often used with beans and vegetables. It germinates best in cool soil and grows steadily during spring. Thin seedlings early to give plants good airflow and room to grow.

Review the Seed Packet Before You Plant

Your seed packet provides essential information for successful direct sowing.

Before planting, review:

• Timing: Recommended planting based on frost dates
• Planting Depth: How deep to sow seeds
• Spacing: Proper spacing for mature plants
• Thinning Instructions: When to thin seedlings

Tips for Successful Direct Sowing in Early Spring

Spring weather can be unpredictable, so keep these tips in mind:

• Wait until the soil is workable, not wet or muddy.
• Water gently to avoid washing seeds away.
• Mark rows clearly to avoid disturbing seedlings.
• Cover young seedlings if a hard freeze is forecast.

If you’re new to direct sowing or want a refresher on planting methods, spacing, and soil preparation, see: How to Direct Sow Seeds.

Can These Seeds Be Planted Earlier or Later?

Timing is flexible, but conditions matter.

• Planting too early in cold, wet soil can slow germination.
• Most of these crops tolerate light frosts once established.
• Delayed planting is still successful, though warm weather may shorten harvests.

Pay attention to soil temperature and weather forecasts for best results.

What to Plant Next

As the last frost date approaches and the soil continues to warm, even more crops become ready for outdoor planting.

Next in the outdoor seed sowing schedule:
Seeds to Direct Sow 2-4 Weeks Before Your Last Frost (Coming Soon). This includes additional cool-season crops that thrive as spring planting ramps up.

Direct sowing during this stage of the season helps build a strong foundation for your garden. With careful timing and a little patience, these early plantings set the stage for weeks of fresh harvests.

Good planning is key to a successful vegetable garden

Whether you are new to growing your own food or have been growing a vegetable garden for years, you will benefit from some planning each year. You will find everything you need to organize and plan your vegetable garden in my PDF eBook, Grow a Good Life Guide to Planning Your Vegetable Garden.