One of the first steps you take when you are estimating 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.

In Johnston you can estimate when it's possible to plant evolvulus by checking out the USDA zone info.

Planting Calendar for Evolvulus

Frost tolerance for evolvulus:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since evolvulus require warm weather you really should wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant evolvulus in Johnston 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 evolvulus and expect a good harvest is probably August. If you wait any later than that and your evolvulus may not have a chance to grow to maturity. Starting your evolvulus indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Johnston. You should expect an average low temperature of -20°F in the coldest months of winter.

Keep in mind that USDA zone info for Johnston is an average and the actual date of last frost changes from year to year. Half of the time in Johnston you get surprised by a frost after April 15 so be sure to be ready to cover your evolvulus in the event of a surprise late frost.

USDA Zone Info for Johnston

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Johnston

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