While gardeners can purchase bedding plants at garden centers and greenhouses in spring, many gardeners prefer to get a head start on the garden season by starting flower and vegetable seedlings indoors. Growing quality seedlings indoors requires high-quality seeds, a well-drained growing medium, containers, proper temperature and moisture conditions, and adequate light.
Germination requirements (light and temperature) vary among annuals and vegetables. The various crops also differ in the length of time from seed sowing until the seedlings are planted outdoors.
More resources on starting seeds can be found in this article: Resources for Seed Starting Indoors.
Below is germination and growing information for commonly grown annual flowers, herbs, and vegetables.
Annuals | Vegetables & Herbs | Vegetables & Herbs Direct Sown in Garden | More Information
Germination Requirements for Select Annuals
| Germination Temperature (°F) | Light Requirements for Germination | Days to Germination | Weeks Sowing to Planting | |
|---|---|---|---|---|
| Ageratum (Ageratum houstonianum) | 70-75 | L | 7-10 | 8 |
| Snapdragon (Antirrhinum majus) | 70 | L | 7-14 | 8-10 |
| Wax Begonia (Begonia x semperflorens-cultorum) | 70-75 | L | 14 | 10-12 |
| Annual Aster (Callistephus chinensis) | 70 | L-D | 7-10 | 6-8 |
| Vinca (Cathranthus roseus) | 70-75 | L-D | 14 | 10 |
| Cockscomb (Cleosia spp.) | 70-75 | D | 7-10 | 6-7 |
| Bachelor's Button (Centaurea cyanus) | 65-70 | L-D | 7-14 | 8 |
| Cosmos (Cosmos spp.) | 70 | D | 5-7 | 4-6 |
| Lisianthus (Eustoma grandiflorum) | 75 | L | 10-14 | 14 |
| Globe Amaranth (Gomphrena globosa) | 70 | L-D | 14 | 7-8 |
| Sunflower* (Helianthus annuus) | 70 | D | 5-7 | 3-4 |
| Strawflower (Helichrysum bracteatum) | 70-75 | L-D | 7-10 | 6-8 |
| Impatiens (Impatiens wallerana) | 70-75 | L | 10-14 | 8-10 |
| Annual Statice (Limonium sinuatum) | 70 | L-D | 7-10 | 8-10 |
| Melampodium (Melampodium paludosum) | 65-70 | L-D | 7-10 | 7 |
| Four-O'Clock (Mirabilis jalapa) | 70 | D | 5-7 | 6-8 |
| Flowering Tobacco (Nicotiana alata) | 70-75 | L | 10-14 | 8 |
| Geranium (Pelargonium x hortorum) | 70-75 | D | 7-21 | 12 |
| Petunia (Petunia x hybrida) | 75 | L | 7-10 | 8-10 |
| Moss Rose (Portulaca grandiflora) | 75 | L | 7-10 | 10 |
| Black-Eyed Susan (Rudbeckia spp.) | 70 | L-D | 7-14 | 10 |
| Red Salvia (Salvia splendens) | 70-75 | L | 10-14 | 8 |
| Mealycup Sage (Salvia farinacea) | 70-75 | L | 10-14 | 8-9 |
| Creeping Zinnia (Sanvitalia procumbens) | 70 | D | 7-10 | 6-7 |
| Coleus (Plectranthus scutellarioides) | 70-75 | L | 10-14 | 8-10 |
| Dahlberg Daisy (Thymophylla tenuiloba) | 65-70 | L | 14 | 8 |
| Nasturtium* (Tropaeolum majus) | 65-70 | D | 10-14 | 5-6 |
| Zinnia (Zinnia elegans) | 70 | D | 5-7 | 5 |
* These species do not transplant well. Should be seeded directly into peat pots.
Germination Requirements for Select Vegetables and Herbs
| Germination Temperature (°F) | Light Requirements for Germination | Days to Germination | Weeks Sowing to Planting | |
|---|---|---|---|---|
| Onion | 70-75 | L-D | 4-20 | 8-10 |
| Dill | 65-70 | L | 7-14 | 5-6 |
| Kale** | 65-70 | D | 4-7 | 4-6 |
| Cauliflower | 65-70 | D | 4-7 | 4-6 |
| Cabbage | 65-70 | D | 4-7 | 4-6 |
| Broccoli | 65-70 | D | 4-7 | 4-6 |
| Brussels Sprouts | 65-70 | D | 5-8 | 4-6 |
| Pepper | 70-75 | D | 7-10 | 6-8 |
| Watermelon** | 75-80 | D | 3-10 | 3-4 |
| Muskmelon** | 75-80 | D | 3-10 | 3-4 |
| Cucumber** | 75-80 | D | 3-10 | 3-4 |
| Squash and Pumpkin** | 75-80 | D | 5-10 | 3-4 |
| Tomato | 70-75 | D | 6-12 | 5-7 |
| Basil | 65-70 | D | 10-14 | 5-6 |
| Parsley | 70-75 | D | 20-25 | 6-8 |
| Eggplant | 70-75 | D | 7-10 | 6-8 |
| Celery | 70-75 | L-D | 14-21 | 10-12 |
** Can be successfully (and frequently are) direct sown in the garden in spring when temperatures are warm enough.
Germination Requirements for Select Vegetables and Herbs that are Direct Sown in the Garden
Plant these vegetables directly in the garden in spring when temperatures are warm enough.
| Germination Temperature (°F) | Light Requirements for Germination | Days to Germination | |
| Beans | 70-80 | D | 8-10 |
| Beets | 50-80 | D | 5-8 |
| Carrots | 50-80 | D | 7-21 |
| Sweet Corn | 65-85 | D | 4-7 |
| Kohlrabi | 65-70 | D | 4-7 |
| Lettuce | 60-70 | L | 7-14 |
| Peas | 50-65 | D | 9-14 |
| Radish | 55-75 | D | 3-4 |
More Information
- Guide to Starting Seed Indoors
- How to Successfully Start Seed Indoors
- Starting Garden Transplants at Home (pub)
- Vegetable Planting and Harvesting Times
- Starting Seeds Indoors FAQs
- Gardening in the Zone: Starting Seeds Indoors (video)
- What are some good sources of flower and vegetable seeds?
- Supplies for Starting Seeds Indoors
- Selecting, Hardening, and Planting Bedding Plants