When to Plant Rosemary in Spring Valley, IL

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Spring Valley you will be able to estimate 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.

Since rosemary are very cold tolerant you can plant them earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant rosemary
Possibly ok, but a risky time to plant rosemary
Probably not a good time to plant rosemary

The earliest that you can plant rosemary in Spring Valley 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. You can get started a few weeks earlier by starting your rosemary indoors.

Last Frost Date

In Spring Valley the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Spring Valley is an average the actual date of last frost will vary from year to year. Half of the time in Spring Valley last frost occurs after April 15 so make sure that you are prepared to cover your rosemary if you have a surprise late frost.

USDA Zone Info for Spring Valley

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 Spring Valley

You may be interested in your other planting guides for Spring Valley.