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

The earliest that you can plant sweet williams in Herndon should be figured out by reviewing 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 do well in moderate cold which tells us that you can plant them earlier than more sensitive plants.

The earliest that you can plant sweet williams in Herndon 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 fully mature. You can get started a few weeks earlier by starting your sweet williams indoors.

Last Frost Date

In Herndon the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Herndon and it changes from year to year. Since half of the time in Herndon it frosts late in the year after April 15 be ready to protect your sweet williams if you have one of those late frosts.

USDA Zone Info for Herndon

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 Herndon

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