One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when it's possible to plant rosemary is to look at the USDA zone info for Lewiston.

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 means that you can plant them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant rosemary in Lewiston 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 fully mature. Starting your rosemary indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Lewiston. In the coldest months of winter you should expect an average low temperature of 5°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 Lewiston and it is different every year. Half of the time in Lewiston there is a last frost after April 15 so be sure to be ready to protect your rosemary if you have one of those late frosts.

USDA Zone Info for Lewiston

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 Lewiston

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