Michigan has a changeable climate with four distinct seasons. According to Farmers' Almanac, the last spring frost arrives around the last week in April in southern cities like Detroit, while it is delayed until the middle of May toward the north in Cheboygan. The first fall frost usually arrives some time in October throughout the state, so the growing season in Michigan generally lasts about six months.
Check with your local county extension service or Farmers' Almanac to find the average last frost date for spring in your area. The date will give you a basic timetable on which you can plan your garden.
Start seeds of tender plants indoors in mid-March, to give them about six weeks in which to grow before transplanting. Plant tomato, pepper and other long-season vegetables in peat pots. Place them in sunny windows when the sprouts appear above the soil, and keep them watered every day.
Dig your garden after the last frost has passed and the soil is drained and crumbly. If the dirt is wet and muddy, wait a few days for it to drain, then check again for better conditions. Dig your soil 6 inches deep and mix in a 4-inch layer of compost.
Plant peas and lettuce as soon as the ground can be worked. These cool-season vegetables love Michigan spring weather and will do well before the hot days of summer arrive.
Transplant your seedlings the first week of May if the ground has drained. Plant cucumber, broccoli, beans, corn and any other long-season plants now, as well as the first batch of carrots and radishes.
Plant another small patch of carrots and radishes in the beginning of June. Carrots generally take about six to eight weeks until harvest, so planting a series of small patches gives you a steady crop throughout the summer.
Plant another batch of peas, lettuce and broccoli in mid-August to take advantage of the coming cooler days. September in Michigan is generally sunny and relatively warm without the high heat of July and August that would make tender vegetables bolt, or go to seed.
Harvest the last of your vegetables by the middle of October. Pull up any plant material and put it on the compost pile.