When Can Marigold Seeds be Planted in Pennsylvania?

Pennsylvania's Climate

• Pennsylvania lies mostly within U.S. Department of Agriculture plant hardiness zones 5 and 6. In the southeastern corner of the state, as well as close to Lake Erie (both zone 6), the last frost date ranges from March 30 to April 30. The biggest part of Pennsylvania, from the northeast to the southwest, is in zone 5 and has an average last frost date between May 1 and May 31. Consult a local garden center for exact frost dates for your area, since altitude and other factors can influence the frost date in your immediate area.

Starting Seeds Outdoors

• Plant marigold seeds directly outdoors after the last expected frost date. Cover emerging seedlings with plastic or a bed sheet if a late frost arrives.

Getting a Head Start Indoors

• Get a head start by planting marigold seeds indoors. Count backwards the required number of weeks from your last frost date. Tall marigolds need four to six weeks' lead time. Shorter varieties need six to eight weeks. Add an extra week to these estimates to acclimate plants to the outdoors before planting.