One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Romeoville can be read to determine when it's the best time to plant scarlet pimpernels.

Planting Calendar for Scarlet Pimpernels

Frost tolerance for scarlet pimpernels:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since scarlet pimpernels are barely cold tolerant you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant scarlet pimpernels in Romeoville is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant scarlet pimpernels and expect a good harvest is probably August. If you wait any later than that and your scarlet pimpernels may not have a chance to grow to maturity. You can get started a little bit earlier by starting your scarlet pimpernels indoors.

Last Frost Date

In Romeoville the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Romeoville is just an average the actual date of last frost changes from year to year. Half of the time in Romeoville there is a last frost after April 15 so make sure that you are ready to protect your scarlet pimpernels if you have a surprise late frost.

USDA Zone Info for Romeoville

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 Romeoville

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