When vegetable gardening is done well it reaps great rewards. Home gardeners enjoy the freshest produce and save money at the same time. Planting too early or too late, however, will destroy a crop. Knowing when to plant is key to a successful harvest.
US Hardiness Zone
North America is broken up into eleven different hardiness zones. These zones are based on average lowest winter temperature each year. There is a difference of 10 degrees F. between each of the zones.
Most of Vermont is in US Hardiness Zone 4. The average low temperatures in Zone 4 are -20 to -30 degrees F. The average last killing frost in the spring in Zone 4 happens in May.
Last frosts can happen earlier or later than expected. Planting seeds before the last killing frost results in dead seeds and no vegetable garden.
Soil Preparation Before Planting Vegetables in Vermont
Even after the danger of a killing frost has passed, the ground must thaw before seeds can survive in the ground. The Old Farmer’s Almanac recommends walking in the garden once the ground is warm. When footprints remain wet or shiny, it means that there is still too much water in the ground to plant seeds. Seeds planted in wet soil will rot. If footprints look dull, however, it is time to plant.
Another soil test from The Old Farmer’s Almanac is picking up a handful of soil to see whether it crumbles or forms a ball. If it forms a ball, it is still too wet to plant. If it crumbles, it is time to plant.
On average, a soil temperature of 65 degrees Fahrenheit is warm enough to plant most crops.
Vermont gardeners may plant different vegetables at different times. Some crops require 90 days or more to reach maturation and be ready to harvest. Other crops have short maturation times.
Lettuce is a fast-growing crop. It may be planted a few times during spring and summer, and even into early fall.
Pumpkins and winter squashes take a few months to mature and should be started as early as possible. With the relatively short growing season in zone 4, many gardeners choose to start their pumpkin seeds early indoors. Some use greenhouses. If not started indoors, pumpkin seeds must be in the ground in early June to have time to produce pumpkins before winter.
Other crops such as peppers, tomatoes, and carrots have shorter maturation times and may be started outside in June or even as late as July.
Many green bean varieties are fast-producing crops that can be re-seeded as the season wears on. For example, plant rows of bush beans. A couple of weeks later, plant more bush bean seeds in between the plants already growing. This ensures an ongoing supply of beans through the season.
In general, wait to plant outside until there is no prediction of killing frost, and re-seed crops with short maturation times for a bountiful harvest.