One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's possible to plant nasturtium in Rock Island by reviewing the USDA zone info.

Planting Calendar for Nasturtium

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

Nasturtium do not do well in cold weather which tells us that it is necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant nasturtium 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 nasturtium and expect a good harvest is probably August. If you wait any later than that and your nasturtium may not have a chance to fully mature. You can get started a few weeks earlier by starting your nasturtium indoors.

Last Frost Date

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

Keep in mind that USDA zone info for Rock Island is just an average and 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 nasturtium if you have 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.