Vegetable Planting Schedule, Hardiness Zone Look-up, & Germination Temperature Chart (2024)

FAQs

What are the optimum germination temperatures for vegetable seeds? ›

An inexpensive soil thermometer helps keep planting time in perspective. “Fifty degrees is a good benchmark for cool-season crops,” Weston said. “And the soil should be 60 degrees or more for warm-weather plants like tomatoes, peppers and basil. In fact, for tomatoes it should ideally be 65 to 70.”

The last frost in most areas of New Jersey happens between mid- to late-April. Therefore, our garden center in New Jersey recommends waiting until the first weekend in May to be safe.

As a general rule, put tall veggies toward the back of the bed, mid-sized ones in the middle, and smaller plants in the front or as a border. Consider adding pollinator plants to attract beneficial insects that can not only help you get a better harvest, but will also prey on garden pests.

Temperatures that reach 130 degrees are enough to kill most weed seeds, but some of the tougher ones (i.e. bindweed, dock, groundsel, speedwell, and lambs quarters) can survive unless temperatures hit 145 degrees for at least a month.

A light freeze is considered 28°-32°F, and a hard freeze below 28°F. However, any temperature below 25°F is dangerous territory for most vegetable plants.

Warm season crops, such as beans, tomatoes, peppers and squash can germinate at minimum soil temperatures of 55 - 60 degrees. The same soil temperatures should also be used when planting transplants.

Mid-March to mid-April—early spring–for planting early, hardy crops. May 1 to June 1—late spring– for planting tender crops. Late June to late July—mid-summer–for planting succession crops warm weather crops and cool-season crops for fall and winter harvest.

What hardiness zone is New Jersey? ›

Knowing your first and last frost dates will help you start your vegetable seeds at the right time. New Jersey is in USDA plant hardiness zones 6-7. Use your last and first frost dates below to calculate your planting schedule.

Starting seeds too early may expose the young plants to pests and diseases that thrive in cooler temperatures.

Most seeds germinate when the soil temperature is between 68° and 86°F. Once germination occurs, the optimum growing temperature for the seedling is about 10°F cooler than the optimum germination temperature.

Ideal temperatures for germination are 70-80 degrees Fahrenheit. Temperatures much lower than 70 degrees will cause slower germination, and if temperatures dip far below, germination may not occur at all. Likewise, hot temperatures well above 80 can also cause germination to fail.

Many factors affect seed germination, but the most challenging for gardeners and often least understood is soil temperature. While there is can be variation from one seed type to the next, most seeds for warm-season edibles prefer soil temperature between 70 and 80 degrees Fahrenheit (21.1 and 26.7 Celsius).

Light stimulates or inhibits the germination of some seeds. Some crops, including ageratum, begonia, browallia, impatiens, lettuce, and petunia require light to help them germinate. Others, such as calendula, centaurea, annual phlox, verbena and vinca germinate best in the dark.