In order to grow seeds indoors, you need to have very strong sunlight or use grow lights. Some seeds germinate in darkness so read any instructions before planting. If using grow lights, keep the seeds a few inches away from the light so they do not burn. Grow lights should be used 12-16 hours per day.
It's important to keep seeds warm at all times and maintain a temperature of 65-85 degrees F. You can use heat mats to increase the temperature if needed. Keep in mind that these may cause the seed mix to dry out faster.
Seeds like to be moist, but not soggy at all times. A spray bottle is recommended for watering. Check seeds at least twice a day to ensure moisture. They dry out fast!
Humidity & Airflow
It's important to maintain high humidity when starting seeds. You can use a seed cover or clear plastic wrap to serve as a greenhouse. Make sure to remove the cover at least 1-2x per day to allow fresh air to flow through. A fan can also be used to help with air circulation. If the airflow is poor and the humidity is too high, the seeds may develop a fungus. Once you see the seeds sprouting with green leaves, you can remove the cover permanently. Once removed, the seeds will dry out faster and may need more regular watering.
Soil & Container
To start seeds, you'll need a seed starting mix or peat pellets. Some of these will need to be hydrated prior to planting so read any instructions carefully. Seed trays, egg cartons, or jiffy pots can be used as containers to start your seeds. Some of these can be planted with your seed into a larger pot as the material break down over time. Seeds should be lightly covered with seed mix. Do not press down too deeply! Follow the directions on seed packs for spacing and depth. Make sure to label your seeds so you remember what type you've planted.
After the second set of leaves appear, you can begin fertilizing. Make sure to dilute the fertilizer to 1/4 or 1/8 strength every 2-3 weeks.
Thinning & Potting
Most seeds benefit from being thinned out. Select the weakest seeds and cut them out with scissors (do not pull). Generally, you want to leave just 1-2 seeds per cell. When seeds have grown at least a few inches (about 4-5 weeks), you can repot them into a larger container two inches bigger than the current pot. Once repotted, water the seeds deeply to encourage the roots to spread out. Seeds should be kept moist, but not soggy at all times.
To acclimate your seeds to the outdoors, move them to a covered outdoor area a little bit each day. The first day, they should be outside for one hour. The second day, two hours and the third day, three hours, etc. Seedlings should be ready to be planted outdoors after one week of hardening off.
Seeds to Start Indoors February/March
Early spring is a great time to begin sowing seeds indoors for plants that will be transplanted outdoors later in the season. Most seed plants can be transplanted outdoors when temperatures warm up in late-April or early May.
Vegetables & Herbs to start indoors
Basil, Broccoli, Cabbage, Cauliflower, Celery, Chamomile, Chives, Cucumber, Echinacea, Eggplant, Fennel, Feverfew, Leeks, Lettuce, Onions, Oregano, Parsley, Peppers, Pumpkin, Rhubarb, Rosemary, Sage, Savory, Sorrel, Squash, Swiss Chard, Thyme, Tomatoes, Watercress
Annuals & Perennials to start indoors
Agastache, Allium, Alyssum, Bachelor’s Buttons, Calendula, Columbine, Echinacea, Grasses, Lavender, Marigolds, Rudbeckia, Salvia, Scabiosa, Snapdragon, Sweet Peas
Seeds to Start Outdoors April/May
Seeds of hardy herbs, vegetables, and annuals can be sown directly outdoors. These plants will tolerate temperatures down to 32 degrees with minimal damage. Most seeds will germinate at soil temperatures around 50-60 degrees F.
Vegetables & Herbs to start outdoors
Arugula, Beans, Beets, Carrots, Chives, Cilantro, Corn, Dill, Fennel, Garlic, Leeks, Mustard, Parsley, Peas, Potatoes, Radishes, Shallots, Turnips
Hardy Annuals & Perennials to start outdoors
Achillea, Asclepias, Poppies, Monarda, Myosotis, Nigella, Phlox