To enjoy those spring flowers, New Englanders should plan to plant in mid-autumn, according to Dr. Leonard P. Perry, a professor of the University of Vermont Extension. Perry recommends planting spring bulbs in mid-September through October.
Tender bulbs, such as dahlias and cannas, require special treatment. These tropical flowers cannot withstand freezing temperatures, so you should plant them only after the danger of frost has passed in your area. The last frost date generally occurs in mid-May through June in New England, according to National Climatic Data Center data.
Planting dates may vary widely based on location, even in a relatively small region like New England. Check with your local extension office or the NCDC website for more information about normal weather for your region and planting dates.