There are basically two options for herb and vegetable gardening: start seedlings indoors and transplanting them to the garden, or buy plants that are already growing in containers. (These will be available in a few months.)
Starting vegetables indoors is easy. You’ll save money and you won’t believe the number of varieties available when you’re buying seeds.
Here’s what you need to know:
Containers: Pick up some plastic cell packs or small peat pots (which can be planted directly into the ground later).
Soil: Seedlings are sensitive to infection and need lots of moisture and nutrition, so look for special “seed starter” soil which will be sterilized, light and airy.
Planting: Plant seeds to the depth specified on your seed packet.
Water: Water with a fine mesh watering can or spritz with a spray bottle. Too much water will wash your seeds away.
Put the containers in another tray filled with pebbles to keep the containers up out of the excess water.
Light: In Minnesota, even a south-facing window probably won’t give enough light. Hang a fluorescent light about four inches above the seedlings.
Heat: Most seeds need a temperature of 68-70 degrees to germinate. To create more heat, you can place glass or plastic over the tops of your containers until the first sprouts emerge. Then remove the covering—the seedlings are now slightly more tolerant of temperature change.
Transplanting: Your plants need a little transition time before you put them into the garden. For a few days, place them outside for several hours in the shade. Then let them spend a night outside while still in the pots. This process of “hardening off” will prevent shock once your plant goes into the garden.
Timing: You need to get an early start, but too much time indoors isn’t good either. Your plants can become spindly and produce less.
Tomato seeds, for example, should be started indoors between April 1 and April 15. Then transplanted to the garden between May 15 and June 1.
Here’s a great link with dates for planting and transplanting your favorite herbs and vegetables in Minnesota gardens: