The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when it's possible to plant sweet williams by reviewing the USDA zone info for Louisville.

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 one of those plants that can tolerate a little bit of cold weather which tells us that you can start planting them earlier than more sensitive plants.

The earliest that you can plant sweet williams in Louisville 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. If you wait any later than that and your sweet williams may not have a chance to grow to maturity. Starting your sweet williams indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Louisville. It might get as low as -10°F during the coldest months of winter.

Remember that USDA zone info for Louisville may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Louisville there is a last frost after April 15 so always be ready to cover your sweet williams in the event of one of those late frosts.

USDA Zone Info for Louisville

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Louisville

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