When to Plant Annuals in Zone 6 [Spring Garden Timing]

If you are planting annuals in zone 6, follow these guidelines:

• Plant annuals outdoors between late-March and mid-April.
• Cold-hardy annuals can be planted in your garden in March.
• Delicate annuals should be planted outside in April.
• Do not plant annuals when nighttime frost is still common.
• Protect annuals from nighttime temperatures below 45℉ (7℃).
• To jumpstart your garden, start sprouting annual seeds indoors in late-February.

By remaining patient and waiting for warm weather, you will prevent cold damage from killing your newly-planted annuals. However, starting plants from seed during late winter will make your garden flourish faster.

What Month is Best to Plant Annuals in Zone 6?

March and April are the best months to plant annuals in Zone 6. The earliest you should begin planting outdoors is the third week of March. If you plant earlier than this, there is a high risk that a cold snap will kill your young annuals. If there is still the threat of frost in your region in late-March, wait until the first or second week of April to begin planting your annuals.

• In zone 6, begin planting annuals in March through April.
• Do not plant annuals earlier than the third week of March unless they are exceptionally cold-hardy.
• Annuals that are somewhat cold hardy can be planted in late-March.
• Delicate annuals should be planted in mid-April.
• Use the last average spring frost in your area to choose the perfect planting time.

Within zone 6, your local climate can differ. Instead of relying only on your zone to determine the correct planting time, use this online tool to find the last spring frost for your zip code. Begin planting hardy annuals 2–3 weeks before the last spring frost. For delicate annuals, wait until after the last spring frost date in your region.

How Cold is Too Cold for Annuals?

If temperatures regularly drop low enough at night for frost to form, it is too cold to plant annuals. Wait until temperatures warm up enough that average nighttime temperatures are consistently above 40℉ (4℃). Then, begin planting your annual fruits, vegetables, and flowers.

• Nighttime temperatures below freezing are too cold for most annuals.
• Wait until the danger of frost is very low before planting annuals.
• Anytime nighttime lows sink below 45℉ (7℃), protect your annuals from the cold.

Nighttime temperatures below 45℉ (7℃) are dangerous for annuals. However, it may not be possible to completely avoid these temperatures with spring plantings in zone 6. So, it’s best to make a plan to protect your new annuals during cold snaps. New plants can be covered with frost blankets during cold nights. Adding a thick layer of mulch to your planting beds will also help to insulate the roots and prevent cold damage.

Should You Start Annuals Indoors in Zone 6?

The best way to prepare for spring planting in Zone 6 is by starting your annuals indoors in February. Use pots and trays filled with potting soil to start seeds for annual flowers, herbs, fruits, and vegetables. When I lived in zone 4, I would start my squash, melons, and pumpkins from seed starting in late February. This same trick can be applied in more temperate regions, such as zone 6.

• If you have the space indoors, begin growing annuals from seed in late winter.
• Fill these seed trays with potting soil, then plant your seeds in the soil.
• Provide light, water, and warm temperatures to your indoor seedlings until the weather warms up.
• Plant your annual seedlings outdoors 3–6 weeks after planting.

Most plants will be ready to transplant into your garden 3 to 6 weeks after you start them. So, it’s a good idea to start your annuals while there is still the danger of frost. Place your seedlings in a south-facing window and augment natural sunlight with a grow light. When you follow this method you can wait to plant your annuals outside once the weather warms up. This will put your garden up to one month ahead of everyone else.

When Can You Plant Annuals in Zone 6?

If you live in USDA plant hardiness zone 6, you can begin to plant cold-tolerant annuals outdoors in the final week of March. Less cold-hardy plants should not be planted outdoors until mid-April. Earlier plantings can be destroyed by frost and cold. The best way to prevent the cold from killing your annuals is to sprout the seeds in indoor containers. Sprout seeds starting in February. Then, plant your annuals outdoors once the danger of frost is past.