Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. 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 basil in Rock Island can be determined by referring to the USDA zone info.

Planting Calendar for Basil

Frost tolerance for basil:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant basil until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant basil in Rock Island is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant basil and expect a good harvest is probably August. Any later than that and your basil may not have a chance to really do well. If you are starting your basil indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Rock Island. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Rock Island and it can change quite a bit from year to year. Since half of the time in Rock Island there is a last frost after April 15 be ready to protect your basil in the event of one of those late frosts.

USDA Zone Info for Rock Island

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 Rock Island

You may be interested in your other planting guides for Rock Island.