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 Rock Island you can determine when it's the best time to plant asparagus fern by using the USDA zone info.

Planting Calendar for Asparagus Fern

Frost tolerance for asparagus fern:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's a bad idea to plant asparagus fern until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant asparagus fern 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 asparagus fern and expect a good harvest is probably August. Any later than that and your asparagus fern may not have a chance to really do well. Starting your asparagus fern indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Rock Island. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Rock Island is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Rock Island you get a frost after April 15 so make sure that you are ready to protect your asparagus fern if you have a late frost.

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.