One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when to plant sweet williams in Louisville by referring to 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.

Since sweet williams do well in moderate cold you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

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. If you are starting your sweet williams indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Louisville. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Louisville is an average the actual date of last frost will vary from year to year. Half of the time in Louisville it frosts late in the year after March 15 so be sure to be ready to cover your sweet williams if you have a late frost.

USDA Zone Info for Louisville

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Louisville

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