One of the best tools that you have as gardeners to help us estimate 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.

In Collinsville you can figure out when it's the best time to plant rosemary by checking out 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 can survive in a bit of cold which tells us that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant rosemary in Collinsville 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. If you are starting your rosemary indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Collinsville the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Remember that USDA zone info for Collinsville is just an average and the actual date of last frost will vary from year to year. Half of the time in Collinsville there is a last frost after April 15 so just be sure to be ready to protect your rosemary if you have one of those late frosts.

USDA Zone Info for Collinsville

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Collinsville

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