Before planting it is a good idea to find your USDA Zone info to determine 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.

In Hillsborough you can figure out when it's possible to plant rosemary by reviewing 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 ok in pretty solid cold which tells us that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant rosemary in Hillsborough 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. You probably don't want to wait any later than that or else your rosemary may not have a chance to grow to maturity. You can get started a little bit earlier by starting your rosemary indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Hillsborough. It might get as low as 5°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Hillsborough is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Hillsborough there is a last frost after April 15 be ready to protect your rosemary if you have one of those late frosts.

USDA Zone Info for Hillsborough

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Hillsborough

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