One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Collingswood should be read to determine when to plant sweet williams.

Planting Calendar for Sweet Williams

Frost tolerance for sweet williams:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Sweet Williams do well in moderate cold which means that you can start planting them earlier than other frost tender plants.

The earliest that you can plant sweet williams in Collingswood is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant sweet williams and expect a good harvest is probably September. You probably don't want to wait any later than that or else your sweet williams may not have a chance to fully mature. Starting your sweet williams indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Collingswood. It might get as low as 0°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Collingswood and it changes from year to year. Half of the time in Collingswood you get surprised by a frost after April 15 so be sure to be ready to cover your sweet williams in the event of one of those late frosts.

USDA Zone Info for Collingswood

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Collingswood

You may be interested in your other planting guides for Collingswood.