One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant rosemary in Zone 1b can be determined by referring to the USDA zone info.

Planting Calendar for Rosemary

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

Rosemary do well in cold weather which tells us that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant rosemary in Zone 1b is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant rosemary and expect a good harvest is probably July. Any later than that and your rosemary may not have a chance to grow to maturity. 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 has passed is on June 15 in Zone 1b. It might get as low as -55°F during 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 Zone 1b and it changes from year to year. Since half of the time in Zone 1b it frosts late in the year after June 15 be ready to cover your rosemary in the event of a late frost.

USDA Zone Info for Zone 1b

Here is the info for USDA Zone 1b.

Average Date of Last Frost (spring)	June 15
Average Date of First Frost (fall)	July 15
Lowest Expected Low	-55°F
Highest Expected Low	-50°F

This means that on a really cold year, the coldest it will get is -55°F. On most years you should be prepared to experience lows near -50°F.

Plants to Grow in Zone 1b

You may be interested in your other planting guides for Zone 1b.