The time of the last spring frost greatly influences vegetable garden planting dates. Other important factors include the soil and daytime growing temperature and the plant preferences.
Frost Free Date
Determine the average date of the last frost in the spring. Find the length of the growing season and the average date of the first fall frost. Vegetables are planted in the spring and if growing conditions allow, planted again for fall harvest.
Cool-season vegetables tolerate light frost and prefer a 60 to 80 degree Fahrenheit growing temperature. Plant hardy vegetables such as onions, turnips, spinach and kohlrabi as soon as the ground can be worked in the spring. Sow semi-hardy vegetable seeds two to three weeks before the date of the last frost. Beets, broccoli, cabbage, carrot, lettuce, peas, potatoes and radishes are classified as semi-hardy vegetables.
Plant tender vegetables such as beans and corn at the time of the last spring frost. Wait until two to three weeks after the last frost to plant very tender vegetables. Cucumbers, eggplant, muskmelon, peppers, pumpkin, squash, tomatoes and sweet potatoes are very tender vegetables. Warm-season vegetables prefer a warm soil and a 70 to 95 degree Fahrenheit daytime temperature.