OK, here's the rule of nature. One plant can live and do relatively well when growing in the Spring, where temps. are 55 low, & 70 high. An identical strain started when the temps are 60 to 75/80, the later planted plant will shoot up fast, catch up to the older plant, and in most cases, do better because the cool nights stunt the growth. Pott is just like tomatoes & peppers in this aspect, they are HEAT-LOVING plants. Each year, there is a great race to plant tomatoes... and most times, they freeze. The Local Nurseries promote this to sell more plants. So don't plant just because others do. To beat the system, (get a jump), compost the ground well if in soil, & cover them every late afternoon with 5 gal. buckets, and remove them each morning once the sun is shining on the bucket. For further cheating, some avid Gardeners use old fashion Christmas lights under the bucket at night, also. Hell, if you do this, may as well line the bucket with mylar. The plants would love it. Solar powered lites may work also...