The Ultimate Seed Starting Calendar for Every Gardening Zone

Embarking on a gardening project can be a deeply rewarding experience, but it requires careful planning and knowledge about when to start your seeds. The United States is divided into various hardiness zones, each with its specific climate conditions, affecting how and when you should plant your seeds. This comprehensive guide will provide a seed starting calendar for 20+ vegetables, tailored to each zone, to ensure your gardening project flourishes.

seed starting calendar

Understanding Hardiness Zones

The USDA Hardiness Zone Map divides North America into 13 zones based on the average annual minimum winter temperature. Each zone is 10°F warmer (or colder) in an average winter than the adjacent zone. Knowing your zone is crucial as it determines the local climate conditions and helps you understand the best planting times for your seeds.

General Tips Before You Start

  1. Check Your Zone: Know your region’s hardiness zone to follow the correct schedule.
  2. Quality Seeds: Purchase high-quality seeds from a reputable source to ensure a good germination rate.
  3. Seed Starting Mix: Use a light, well-draining soil mix, specifically designed for seed starting.
  4. Proper Containers: Ensure your containers have good drainage and are clean to prevent diseases.
  5. Adequate Light: Seedlings need a lot of light; if you’re growing indoors, consider a grow light.
  6. Keep Track: Label your seeds and keep a gardening journal to track their progress.

Seed Starting Calendar for Each Zone

Below are seed starting calendars for Zones 3 to 10. Each table lists over 20 vegetables, when to start them indoors, and the ideal time to transplant them outdoors.


Zone 3 Seed Starting Calendar

In Zone 3, the growing season is short and the risk of frost is high well into the spring. It’s important to start most of your seeds indoors to give your plants enough time to mature before the first frost in the fall. Here is a detailed seed starting calendar for over 20 vegetables suitable for Zone 3:

PlantStart IndoorsTransplant Outdoors
TomatoesEarly MarchLate May to early June
PeppersEarly MarchLate May to early June
EggplantEarly MarchLate May to early June
BroccoliEarly MarchLate May
CauliflowerEarly MarchLate May
KaleEarly MarchLate May
CabbageMid-MarchLate May
Brussel SproutsMid-MarchLate May
LettuceMid-MarchLate May
SpinachMid-MarchLate May
Swiss ChardMid-MarchLate May
CollardsMid-MarchLate May
CucumbersMid-AprilEarly June
Squash (Summer)Mid-AprilEarly June
Squash (Winter)Mid-AprilEarly June
PumpkinsMid-AprilEarly June
MelonsMid-AprilEarly June
ZucchiniMid-AprilEarly June
Onions (from seed)Early MarchLate May
LeeksEarly MarchLate May
Parsnips(Direct sow outdoors)Early to mid-April
Carrots(Direct sow outdoors)Early to mid-April
Beets(Direct sow outdoors)Early to mid-April
Radishes(Direct sow outdoors)Early to mid-April
Peas(Direct sow outdoors)As soon as the soil can be worked

Note: The dates are approximate and can vary based on specific local weather conditions. It’s always a good idea to check the last frost date in your area and adjust your planting schedule accordingly. For crops sown directly outdoors, ensure the soil is workable and not too cold or waterlogged.

Remember, the key to a successful garden in Zone 3 is starting your seeds early indoors and protecting your seedlings from the last spring frosts. Happy gardening!


Zone 4 Seed Starting Calendar

Zone 4 has a slightly longer growing season than Zone 3, but gardeners still face the challenge of a short warm period and the possibility of late spring frosts. Starting seeds indoors is essential for many vegetables to ensure they mature before the first fall frost. Here’s a seed starting calendar for over 20 vegetables ideal for Zone 4:

PlantStart IndoorsTransplant Outdoors
TomatoesMid-MarchEarly to mid-June
PeppersMid-MarchEarly to mid-June
EggplantMid-MarchEarly to mid-June
BroccoliMid to late MarchLate May to early June
CauliflowerMid to late MarchLate May to early June
KaleMid to late MarchLate May to early June
CabbageLate MarchLate May to early June
Brussel SproutsLate MarchLate May to early June
LettuceLate MarchLate May to early June
SpinachLate MarchLate May to early June
Swiss ChardLate MarchLate May to early June
CollardsLate MarchLate May to early June
CucumbersLate AprilEarly to mid-June
Squash (Summer)Late AprilEarly to mid-June
Squash (Winter)Late AprilEarly to mid-June
PumpkinsLate AprilEarly to mid-June
MelonsLate AprilEarly to mid-June
ZucchiniLate AprilEarly to mid-June
Onions (from seed)Mid-MarchLate May to early June
LeeksMid-MarchLate May to early June
Parsnips(Direct sow outdoors)Late April to early May
Carrots(Direct sow outdoors)Late April to early May
Beets(Direct sow outdoors)Late April to early May
Radishes(Direct sow outdoors)Late April to early May
Peas(Direct sow outdoors)As soon as the soil can be worked

Note: The dates are approximate and can vary based on specific local weather conditions. Check the last frost date in your area and adjust your planting schedule accordingly. For crops sown directly outdoors, ensure the soil is workable and not too cold or waterlogged.

In Zone 4, taking advantage of the entire growing season is crucial. By starting your seeds indoors and preparing for the last spring frosts, you can maximize your harvest. Happy planting!


Zone 5 Seed Starting Calendar

In Zone 5, gardeners enjoy a more moderate growing season, allowing for a wide range of vegetables to be grown. However, starting seeds indoors is still a critical step for many plants, especially those that need a longer season to mature. Below is a seed starting calendar for over 20 vegetables suitable for Zone 5:

PlantStart IndoorsTransplant Outdoors
TomatoesEarly MarchLate May
PeppersEarly MarchLate May
EggplantEarly MarchLate May
BroccoliEarly to Mid-MarchLate May
CauliflowerEarly to Mid-MarchLate May
KaleEarly to Mid-MarchLate May
CabbageMid-MarchLate May
Brussel SproutsMid-MarchLate May
LettuceMid-MarchLate May
SpinachMid-MarchLate May
Swiss ChardMid-MarchLate May
CollardsMid-MarchLate May
CucumbersEarly AprilEarly to mid-June
Squash (Summer)Early AprilEarly to mid-June
Squash (Winter)Early AprilEarly to mid-June
PumpkinsEarly AprilEarly to mid-June
MelonsEarly AprilEarly to mid-June
ZucchiniEarly AprilEarly to mid-June
Onions (from seed)Early MarchLate May
LeeksEarly MarchLate May
Parsnips(Direct sow outdoors)Late April
Carrots(Direct sow outdoors)Late April
Beets(Direct sow outdoors)Late April
Radishes(Direct sow outdoors)Late April
Peas(Direct sow outdoors)As soon as the soil can be worked

Note: The dates are approximate and can vary based on specific local weather conditions. Check the last frost date in your area and adjust your planting schedule accordingly. For crops sown directly outdoors, ensure the soil is workable and not too cold or waterlogged.

Zone 5 offers a more generous growing season, but taking advantage of the warmth is still crucial for a successful harvest. By starting your seeds indoors for warmth-loving plants and preparing the soil for direct sowing, you can ensure a bountiful and diverse garden. Happy gardening!


Zone 6 Seed Starting Calendar

Zone 6 gardeners benefit from a longer growing season compared to Zones 3-5, providing more flexibility for planting a variety of vegetables. Starting seeds indoors is still beneficial for certain crops, particularly those that prefer warm conditions or have a longer maturation period. Here’s a seed starting calendar for over 20 vegetables ideal for Zone 6:

PlantStart IndoorsTransplant Outdoors
TomatoesLate February to early MarchMid-May
PeppersLate February to early MarchMid-May
EggplantLate February to early MarchMid-May
BroccoliEarly MarchMid to late May
CauliflowerEarly MarchMid to late May
KaleEarly MarchMid to late May
CabbageMid-MarchMid to late May
Brussel SproutsMid-MarchMid to late May
LettuceMid-MarchMid to late May
SpinachMid-MarchMid to late May
Swiss ChardMid-MarchMid to late May
CollardsMid-MarchMid to late May
CucumbersEarly AprilLate May to early June
Squash (Summer)Early AprilLate May to early June
Squash (Winter)Early AprilLate May to early June
PumpkinsEarly AprilLate May to early June
MelonsEarly AprilLate May to early June
ZucchiniEarly AprilLate May to early June
Onions (from seed)Late February to early MarchMid to late May
LeeksLate February to early MarchMid to late May
Parsnips(Direct sow outdoors)Early to mid-April
Carrots(Direct sow outdoors)Early to mid-April
Beets(Direct sow outdoors)Early to mid-April
Radishes(Direct sow outdoors)Early to mid-April
Peas(Direct sow outdoors)As soon as the soil can be worked

Note: The dates are approximate and can vary based on specific local weather conditions. Check the last frost date in your area and adjust your planting schedule accordingly. For crops sown directly outdoors, ensure the soil is workable and not too cold or waterlogged.

Zone 6 offers a favorable growing season, but starting seeds indoors for warmth-loving plants and preparing for direct sowing outdoors for cold-tolerant crops will help maximize your garden’s potential. Enjoy your planting journey!


Zone 7 Seed Starting Calendar

Zone 7 offers a moderate growing season, providing ample opportunities for a variety of vegetables to thrive. While the risk of frost is less severe compared to colder zones, starting seeds indoors is still beneficial for warmth-loving plants or those with a longer growing period. Here’s a seed starting calendar for over 20 vegetables suitable for Zone 7:

PlantStart IndoorsTransplant Outdoors
TomatoesMid-FebruaryEarly May
PeppersMid-FebruaryEarly May
EggplantMid-FebruaryEarly May
BroccoliLate FebruaryMid to late April
CauliflowerLate FebruaryMid to late April
KaleLate FebruaryMid to late April
CabbageEarly MarchMid to late April
Brussel SproutsEarly MarchMid to late April
LettuceEarly MarchMid to late April
SpinachEarly MarchMid to late April
Swiss ChardEarly MarchMid to late April
CollardsEarly MarchMid to late April
CucumbersLate MarchEarly May
Squash (Summer)Late MarchEarly May
Squash (Winter)Late MarchEarly May
PumpkinsLate MarchEarly May
MelonsLate MarchEarly May
ZucchiniLate MarchEarly May
Onions (from seed)Mid-FebruaryEarly to mid-April
LeeksMid-FebruaryEarly to mid-April
Parsnips(Direct sow outdoors)Mid-April
Carrots(Direct sow outdoors)Mid-April
Beets(Direct sow outdoors)Mid-April
Radishes(Direct sow outdoors)Mid-April
Peas(Direct sow outdoors)As soon as the soil can be worked

Note: The dates are approximate and can vary based on specific local weather conditions. Check the last frost date in your area and adjust your planting schedule accordingly. For crops sown directly outdoors, ensure the soil is workable and not too cold or waterlogged.

In Zone 7, taking advantage of the moderate growing season is key. By starting your seeds indoors for warmth-loving plants and preparing the soil for direct sowing, you can ensure a productive and diverse garden. Happy gardening!

Zone 8 Seed Starting Calendar

Zone 8 gardeners enjoy a long growing season, allowing for a wide range of vegetables to be planted and nurtured. The mild winters and early springs provide a great opportunity to start seeds both indoors and outdoors. Here’s a seed starting calendar for over 20 vegetables ideal for Zone 8:

PlantStart IndoorsTransplant Outdoors
TomatoesEarly FebruaryLate April
PeppersEarly FebruaryLate April
EggplantEarly FebruaryLate April
BroccoliEarly FebruaryEarly to mid-April
CauliflowerEarly FebruaryEarly to mid-April
KaleEarly FebruaryEarly to mid-April
CabbageMid-FebruaryEarly to mid-April
Brussel SproutsMid-FebruaryEarly to mid-April
LettuceMid-FebruaryEarly to mid-April
SpinachMid-FebruaryEarly to mid-April
Swiss ChardMid-FebruaryEarly to mid-April
CollardsMid-FebruaryEarly to mid-April
CucumbersEarly MarchLate April to early May
Squash (Summer)Early MarchLate April to early May
Squash (Winter)Early MarchLate April to early May
PumpkinsEarly MarchLate April to early May
MelonsEarly MarchLate April to early May
ZucchiniEarly MarchLate April to early May
Onions (from seed)Early FebruaryEarly to mid-April
LeeksEarly FebruaryEarly to mid-April
Parsnips(Direct sow outdoors)Early to mid-March
Carrots(Direct sow outdoors)Early to mid-March
Beets(Direct sow outdoors)Early to mid-March
Radishes(Direct sow outdoors)Early to mid-March
Peas(Direct sow outdoors)As soon as the soil can be worked

Note: The dates are approximate and can vary based on specific local weather conditions. Check the last frost date in your area and adjust your planting schedule accordingly. For crops sown directly outdoors, ensure the soil is workable and not too cold or waterlogged.

Zone 8 offers a favorable climate for a variety of vegetables. Starting seeds indoors for heat-loving plants and preparing for direct sowing outdoors for others will help maximize your garden’s productivity. Enjoy the lush growth!


Zone 9 Seed Starting Calendar

Zone 9 is characterized by a very long growing season and mild winters, making it an ideal environment for a wide array of vegetables. Gardeners in this zone can enjoy multiple planting cycles and have the flexibility to start seeds both indoors and directly outdoors. Here’s a seed starting calendar for over 20 vegetables suitable for Zone 9:

PlantStart IndoorsTransplant Outdoors
TomatoesMid-JanuaryEarly April
PeppersMid-JanuaryEarly April
EggplantMid-JanuaryEarly April
BroccoliEarly JanuaryLate February to early March
CauliflowerEarly JanuaryLate February to early March
KaleEarly JanuaryLate February to early March
CabbageLate JanuaryLate February to early March
Brussel SproutsLate JanuaryLate February to early March
LettuceLate JanuaryLate February to early March
SpinachLate JanuaryLate February to early March
Swiss ChardLate JanuaryLate February to early March
CollardsLate JanuaryLate February to early March
CucumbersEarly FebruaryMid to late March
Squash (Summer)Early FebruaryMid to late March
Squash (Winter)Early FebruaryMid to late March
PumpkinsEarly FebruaryMid to late March
MelonsEarly FebruaryMid to late March
ZucchiniEarly FebruaryMid to late March
Onions (from seed)Mid-JanuaryLate February to early March
LeeksMid-JanuaryLate February to early March
Parsnips(Direct sow outdoors)Early February
Carrots(Direct sow outdoors)Early February
Beets(Direct sow outdoors)Early February
Radishes(Direct sow outdoors)Early February
Peas(Direct sow outdoors)Early February or as soon as the soil can be worked

Note: The dates are approximate and can vary based on specific local weather conditions. In Zone 9, it’s important to monitor the temperatures closely, as heatwaves can stress plants. For crops sown directly outdoors, ensure the soil is workable and not too cold or waterlogged.

Zone 9’s long growing season and mild temperatures offer a great opportunity for a thriving garden. Starting seeds indoors for heat-loving plants and preparing for direct sowing outdoors for others will help ensure a continuous and bountiful harvest throughout the year. Enjoy your lush, productive garden!


Zone 10 Seed Starting Calendar

Zone 10 is characterized by its warm climate year-round, providing an exceptional environment for growing a wide range of vegetables. Gardeners in this zone can enjoy multiple planting cycles and have the opportunity to grow plants continuously throughout the year. Here’s a seed starting calendar for over 20 vegetables suitable for Zone 10:

PlantStart IndoorsTransplant Outdoors
TomatoesLate December to early JanuaryLate March
PeppersLate December to early JanuaryLate March
EggplantLate December to early JanuaryLate March
BroccoliEarly JanuaryLate February
CauliflowerEarly JanuaryLate February
KaleEarly JanuaryLate February
CabbageMid-JanuaryLate February
Brussel SproutsMid-JanuaryLate February
LettuceMid-JanuaryLate February
SpinachMid-JanuaryLate February
Swiss ChardMid-JanuaryLate February
CollardsMid-JanuaryLate February
CucumbersLate JanuaryEarly March
Squash (Summer)Late JanuaryEarly March
Squash (Winter)Late JanuaryEarly March
PumpkinsLate JanuaryEarly March
MelonsLate JanuaryEarly March
ZucchiniLate JanuaryEarly March
Onions (from seed)Late December to early JanuaryLate February
LeeksLate December to early JanuaryLate February
Parsnips(Direct sow outdoors)Early January
Carrots(Direct sow outdoors)Early January
Beets(Direct sow outdoors)Early January
Radishes(Direct sow outdoors)Early January
Peas(Direct sow outdoors)Early January or as soon as the soil can be worked

Note: The dates are approximate and can vary based on specific local weather conditions. Zone 10’s warm climate allows for a year-round growing season, but it’s important to be mindful of the intense heat during the summer months, which can stress some plants. For crops sown directly outdoors, ensure the soil is workable and not too hot.

In Zone 10, the warm temperatures and long growing season provide an excellent opportunity for a continuous and diverse garden. Starting seeds indoors for temperature-sensitive plants and preparing for direct sowing outdoors for others will help ensure a vibrant and productive garden throughout the year. Happy gardening in the warmth of Zone 10!

Final Thoughts

Starting seeds can be a delightful journey. Each plant and zone has its requirements and timings, making it crucial to plan accordingly. By following these calendars and adjusting as needed based on your local climate conditions, you’ll be well on your way to a bountiful harvest. Happy gardening!

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