When to Plant Sweet Williams in Swarthmore, PA

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant sweet williams in Swarthmore can be figured out by using the USDA zone info.


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 are moderately cold tolerant which means that you can start planting them earlier than more sensitive plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant sweet williams
Possibly ok, but a risky time to plant sweet williams
Probably not a good time to plant sweet williams

The earliest that you can plant sweet williams in Swarthmore 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. Any later than that and your sweet williams may not have a chance to really do well. You can get started a little bit earlier by starting your sweet williams indoors.

Last Frost Date

On average the last frost is on April 15 in Swarthmore. You should expect an average low temperature of 0°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Swarthmore and it changes from year to year. Half of the time in Swarthmore you get a frost after April 15 so make sure that you are prepared to protect your sweet williams if you have one of those late frosts.

USDA Zone Info for Swarthmore

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 Low0°F
Highest Expected Low5°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 Swarthmore

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