To start seeds indoors start with good seed, properly moist starting mix, and a seedling heat mat to ensure proper temperature.
Start with fresh seeds that have been stored properly.
Keep records and properly tag your seedlings to avoid confusion when it’s time to plant.
Pre-moisten soil – Use a good quality seed starter Mix, soak in water for a few minutes to properly moisten. After soil is wet scoop it out and fill shallow containers with good drainage.
Do not plant seeds too deeply. Extremely fine seed are not covered, but lightly pressed into the soil and watered in with a fine mist.
Large seeds are frequently sown into a small container or cell pack which eliminates the need for early transplanting. 2 or 3 seeds are sown per unit and lightly cover with soil and spray with mister. Thin later, allow the strongest seedling to grow.
Use a seedling heat mat – I would never try to start seed seedling without using a heat mat. Maintaining warm soil temperature
One week before transplanting your seedlings outdoors, start to harden them off. This process acclimates the soft and tender plants, which have been protected from wind, cool temperatures, and strong sun, to their new environment. Move the plants to a shady outdoor area at first, and bring them indoors for the night if night temperatures are cold. Each day, move them out into the sun for a few hours, increasing the time spent in the sun each day. Keep them well watered during this period, and don’t place them directly on the ground if slugs are a problem. Monitor them closely for insect damage since tender young seedlings are a delicacy for insects.
| Plant Indoors Before Last Frost | Approximate Germination Time (days) | Germination Temperature Degrees F. | Germination Light (L) Dark (D) |
| 12 weeks or more | |||
| Begonia Browallia Geranium Larkspur Pansy Vinca |
10-15 15-20 10-20 5-10 5-10 10-15 |
70 70 70 55 65 70 |
L L L D D D |
| 10 weeks | |||
| Dianthus Impatiens Petunia Portulaca Snapdragon Stock Verbena |
5-10 15-20 5-10 5-10 5-10 10-15 15-20 |
70 70 70 70 65 70 65 |
— L L D L — D |
| 8 weeks | |||
| Ageratum Alyssum Broccoli Cabbage Cauliflower Celosia Coleus Dahlia Eggplant Head lettuce Nicotiana Pepper Phlox |
5-10 5-10 5-10 5-10 5-10 5-10 5-10 5-10 5-10 5-10 10-15 5-10 5-10 |
70 70 70 70 70 70 65 70 70 70 70 80 65 |
L — — — — — L — — L L — D |
| 6 weeks | |||
| Aster Balsam Centurea Marigold Tomato Zinnia |
5-10 5-10 5-10 5-10 5-10 5-10 |
70 70 65 70 80 70 |
— — D — — — |
| 4 weeks or less | |||
| Cucumber Cosmos Muskmelon Squash Watermelon |
5-10 5-10 5-10 5-10 5-10 |
85 85 85 85 85 |
— — — — — |