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.

By checking out the USDA zone info for Harvard it's a good idea to figure out when it's a good idea to 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 are very cold tolerant which tells us that you can start planting them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant rosemary in Harvard 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. If you wait any later than that and your rosemary may not have a chance to fully mature. If you are starting your rosemary indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Harvard. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Harvard and it can change quite a bit from year to year. Half of the time in Harvard there is a last frost after April 15 so make sure that you are prepared to protect your rosemary if you have a surprise late frost.

USDA Zone Info for Harvard

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 Harvard

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