Sweet peas (Lathyrus odoratus) can survive some chilly weather and you can plant them out around the last frost date for your area, which is approximately May 1st, depending upon your precise location. Make sure that your seedlings are getting lots of light now and pinch out the growing point when they are about six inches tall to encourage branching. These beautiful plants need strong nutritional support to produce abundant flowers, so prepare the planting location with compost and fertilizer amendments before transplanting.

Courtesy of NYBG Plant Information Service