The USDA Zone info is a great tool for gardeners to help us estimate 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.

The USDA zone info for Mount Vernon can be reffered to in order to determine when you can plant rosemary.

Planting Calendar for Rosemary

Frost tolerance for rosemary:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Rosemary can survive in cold weather which tells us that you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant rosemary in Mount Vernon 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 rosemary and expect a good harvest is probably September. Any later than that and your rosemary may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your rosemary indoors.

Last Frost Date

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

Since the USDA zone info for Mount Vernon is just an average the actual date of last frost changes from year to year. Since half of the time in Mount Vernon there is a last frost after April 15 be ready to cover your rosemary in the event of a surprise late frost.

USDA Zone Info for Mount Vernon

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Mount Vernon

You may be interested in your other planting guides for Mount Vernon.