Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's possible to plant sweet williams by reviewing the USDA zone info for Napoleon.

Planting Calendar for Sweet Williams

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

You can plant sweet williams just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant sweet williams in Napoleon 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. If you are starting your sweet williams indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Napoleon. It might get as low as -10°F during the coldest months of winter.

It's important to remember that USDA zone info for Napoleon is just an average and the actual date of last frost is different every year. Half of the time in Napoleon there is a last frost after April 15 so just be sure to be ready to cover your sweet williams in the event of one of those late frosts.

USDA Zone Info for Napoleon

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 Napoleon

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