What is the best time to start planting seeds? This question crosses the mind of every gardener, novice or experienced. Whether you’re wondering which vegetable to grow in which month or which season is best for growing seeds, it’s crucial to get the timing right for a successful garden. The good news is that some vegetables grow in all seasons, offering flexibility in planting schedules. To help you navigate this gardening maze, we’ve created a zone-wise calendar covering vegetables and flowers so you can plan your indoor seed starting with precision.
When to Start Seeds Indoors Chart
When to Start Seeds Indoors Zone 1
Zone 1 is the coldest USDA hardiness zone, encompassing regions with extremely harsh winter conditions, such as parts of Alaska. This zone is often further divided into subzones 1a and 1b, with slight differences in temperature ranges. Starting seeds indoors for areas in Zone 1 can provide a much-needed head start to achieve a successful growing season.
Zone 2 covers some of the coldest parts of the continental United States, such as northern Alaska and high mountain areas. This zone also has subzones—2a and 2b. Due to the short growing season, starting vegetable and flower seeds indoors is often essential for a fruitful harvest.
Zone 2 Flower Seeds Starting Indoors Chart
Flower Type
Start Month
End Month
Pansies
January
February
Daffodils
February
March
Tulips
March
April
Snapdragons
March
April
Roses
April
May
Lilies
April
May
Orchids
May
June
Lavender
May
June
Daisies
June
July
Violets
June
July
Zone 2 Vegetable Seeds Starting Indoors Chart
Vegetable Type
Start Month
End Month
Onions
January
February
Leeks
January
February
Carrots
February
March
Broccoli
March
April
Cauliflower
March
April
Cabbage
April
May
Celery
April
May
Pumpkins
May
June
Squash
May
June
Zucchini
June
July
When to Start Seeds Indoors Zone 3
Zone 3 includes northern states like parts of Montana, North Dakota, and Minnesota. This zone also has subzones 3a and 3b. The growing season is relatively short, making it advantageous to start seeds indoors to maximize the growing period.
Zone 4 includes parts of states like Wyoming, Montana, and Wisconsin. It consists of subzones 4a and 4b. In Zone 4, planting seeds indoors allows for a broader range of vegetable and flower options, as the outdoor growing season can be limited.
Zone 4 Flower Seeds Starting Indoors Chart
Flower Type
Start Month
End Month
Daffodils
February
March
Tulips
February
March
Petunias
March
April
Orchids
March
April
Cosmos
April
May
Sunflowers
April
May
Begonias
May
June
Lavender
May
June
Zinnias
June
July
Roses
June
July
Zone 4 Vegetable Seeds Starting Indoors Chart
Vegetable Type
Start Month
End Month
Peas
February
March
Kale
February
March
Spinach
March
April
Lettuce
March
April
Broccoli
April
May
Cauliflower
April
May
Tomatoes
May
June
Peppers
May
June
Carrots
June
July
Pumpkins
June
July
When to Start Seeds Indoors Zone 5
Zone 5 spans states such as Iowa, Illinois, and Nebraska, containing subzones 5a and 5b. Starting seeds indoors in Zone 5 allows gardeners to get a jumpstart on the growing season, which is still relatively short compared to warmer zones.
Zone 5 Flower Seeds Starting Indoors Chart
Flower Type
Start Month
End Month
Daffodils
February
March
Tulips
February
March
Lilies
March
April
Roses
March
April
Orchids
April
May
Daisies
April
May
Petunias
May
June
Lavender
May
June
Zinnias
June
July
Marigolds
June
July
Zone 5 Vegetable Seeds Starting Indoors Chart
Vegetable Type
Start Month
End Month
Onions
February
March
Leeks
February
March
Radishes
March
April
Carrots
March
April
Spinach
April
May
Peas
April
May
Tomatoes
May
June
Cucumbers
May
June
Peppers
June
July
Zucchini
June
July
When to Start Seeds Indoors Zone 6
Zone 6 covers parts of states like Missouri, Kansas, and Ohio, divided into subzones 6a and 6b. Starting seeds indoors in this zone provides a good head start, especially for plants that require a longer growing season.
Zone 7 includes regions in states like Oklahoma, Arkansas, and Virginia. This zone is also divided into subzones 7a and 7b. Starting seeds indoors in Zone 7 gives you more flexibility in choosing plant varieties, as the growing season is relatively longer than in colder zones.
Zone 7 Flower Seeds Starting Indoors Chart
Flower Type
Start Month
End Month
Pansies
February
March
Orchids
February
March
Roses
March
April
Sunflowers
March
April
Lavender
April
May
Daisies
April
May
Tulips
May
June
Petunias
May
June
Begonias
June
July
Marigolds
June
July
Zone 7 Vegetable Seeds Starting Indoors Chart
Vegetable Type
Start Month
End Month
Leeks
February
March
Onions
February
March
Beets
March
April
Radishes
March
April
Kale
April
May
Broccoli
April
May
Cabbage
May
June
Cauliflower
May
June
Tomatoes
June
July
Peppers
June
July
When to Start Seeds Indoors Zone 8
Zone 8 encompasses Texas, Georgia, and North Carolina, with subzones 8a and 8b. Starting seeds indoors in this zone can benefit certain varieties that require longer maturity.
Zone 8 Flower Seeds Starting Indoors Chart
Flower Type
Start Month
End Month
Orchids
February
March
Roses
February
March
Daffodils
March
April
Lilies
March
April
Petunias
April
May
Lavender
April
May
Zinnias
May
June
Marigolds
May
June
Begonias
June
July
Sunflowers
June
July
Zone 8 Vegetable Seeds Starting Indoors Chart
Vegetable Type
Start Month
End Month
Radishes
February
March
Spinach
February
March
Peas
March
April
Lettuce
March
April
Kale
April
May
Cucumbers
April
May
Tomatoes
May
June
Peppers
May
June
Zucchini
June
July
Pumpkins
June
July
When to Start Seeds Indoors Zone 9
Zone 9 includes parts of Florida, California, and Arizona, with subzones 9a and 9b. Although the growing season is quite long, starting seeds indoors allows for a broader range of vegetable and flower options, including those that require more care and time.
Zone 10 covers regions in states like southern Florida and southern California, with subzones 10a and 10b. While the growing season is long and warm, planting seeds indoors can provide better control over growing conditions.
Zone 10 Flower Seeds Starting Indoors Chart
Flower Type
Start Month
End Month
Roses
January
February
Orchids
January
February
Lavender
February
March
Daffodils
February
March
Sunflowers
March
April
Petunias
March
April
Zinnias
April
May
Tulips
April
May
Begonias
May
June
Marigolds
May
June
Zone 10 Vegetable Seeds Starting Indoors Chart
Vegetable Type
Start Month
End Month
Spinach
January
February
Radishes
January
February
Peas
February
March
Tomatoes
February
March
Peppers
March
April
Lettuce
March
April
Kale
April
May
Cucumbers
April
May
Zucchini
May
June
Pumpkins
May
June
When to Start Seeds Indoors Zone 11
Zone 11 includes the warmest parts of the United States, such as Hawaii and Puerto Rico. Subzones are less commonly used in this zone. Given the extended growing season, there is less need to start seeds indoors, but doing so can still offer advantages for certain plant types.
Zone 11 Flower Seeds Starting Indoors Chart
Flower Type
Start Month
End Month
Orchids
December
January
Roses
December
January
Lavender
January
February
Sunflowers
January
February
Petunias
February
March
Zinnias
February
March
Tulips
March
April
Begonias
March
April
Daffodils
April
May
Marigolds
April
May
Zone 11 Vegetable Seeds Starting Indoors Chart
Vegetable Type
Start Month
End Month
Spinach
December
January
Radishes
December
January
Tomatoes
January
February
Peas
January
February
Peppers
February
March
Lettuce
February
March
Kale
March
April
Cucumbers
March
April
Zucchini
April
May
Pumpkins
April
May
When to Start Seeds Indoors Zone 12 and 13
Zones 12 and 13 are not commonly found in the continental United States but may apply to some U.S. territories with tropical climates. Subzones are less frequently defined for these zones. Starting seeds indoors is generally less critical due to the extended growing season, but it may still be advantageous for some specialized plants.
Understanding the USDA hardiness zones and their respective subzones is essential for any gardener to maximize their yield and variety of vegetables and flowers. Each zone has unique challenges and advantages, from the frigid conditions of Zone 1 in Alaska to the tropical climates of Zone 11 in Hawaii and U.S. territories.
Starting seeds indoors offers a viable solution to circumvent some challenges, especially in colder zones with shorter growing seasons. It allows gardeners to extend their growing calendars and choose from a more extensive range of plant types that may not otherwise thrive if directly sown outdoors. Equally, while the growing season may be extensive in warmer zones, starting seeds indoors can provide optimal conditions for plants that require a more controlled environment.
The adaptability of this practice across zones suggests that it’s not just a function of necessity in colder climates but a strategy that can benefit gardeners everywhere. So whether you find yourself battling harsh winters or managing the challenges of a prolonged growing season, a little planning and understanding of your zone-specific needs can go a long way in ensuring a fruitful and blooming garden.
