Here are some things to look for:
Adequate Light: If you can’t use a south facing window, or don’t get enough natural light in your climate (a real problem here in cloudy Michigan!), you will need to use artificial lights. Insufficient light will produce leggy, weak plants. The plants need about 16 hours of strong light each day.
Warmth: Many seedlings want to grow in conditions between 65-75 degrees Fahrenheit. While the basem*nt may seem like a good space, many basem*nts are too cold and the plants will grow very slowly. This can be overcome by leaving the plants on a heat mat to provide supplemental warmth.
Air Flow: If the space does not have good air flow, a small fan can provide the necessary air movement to prevent disease problems.
Safe from Pets: This can be a real issue! Cats love to lay on heat mats and flatten your tender seedlings (ask me how I know this. Ha!). They might even think your seed trays are litter boxes. Eek! Dogs may like to eat the soil.
Proximity to Water Sources: You will need to water your babies frequently, so be sure they are in a location that has easy to access to water… or else you’ll get lazy and won’t water them enough (oh, is that just me?).
Timing of Sowing
It’s important to know your Average Last Spring Frost Date. Do a simple web search to find the Average Last Spring Frost Date in your area.
This is the date when it’s safe to plant most flowers, veggies and herbs outdoors.If you plant outdoors before this date, you risk losing your plants to a late spring frost. (There are some plants that are “hardy” or “frost tolerant” that can be planted out before this date. Check the seed packet to be sure.)
While it seems counterintuitive, err on the side of sowing seeds a bit later rather than earlier. Seeds that are sown too early can result in plants that are rootbound and stunted, or may try to bloom at 2 inches tall. Eek!
Here are some rough guidelines/suggestions for commonly grown flowers, veggies and herbs. You may need to experiment to find the correct timing for your climate.
8-10 Weeks before Average Last Spring Frost
Carnation
Feverfew
Onion/Leek
Pepper (Hot or sweet)
Sweet William
Yarrow
6-8 Weeks before Last Average Spring Frost
Ageratum
Bells of Ireland
Delphinium
Herbs (perennial types, like chives, oregano, sage, thyme, etc)
Phlox
Poppy
Sweet Annie
4-6 Weeks before Last Average Frost
Ammi (False Queen Anne’s Lace)
Bachelor’s Button
Basil
Broccoli
Cabbage
Cauliflower
Forget-Me-Not
Kale
Lettuce
Marigold
Morning Glory
Sweet Pea
Tomato
2-4 Weeks before Average Last Spring Frost
Cucumber
Melon
Nasturtium
Pumpkin
Squash
Watermelon