One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

In Romeoville you can determine when it's a good idea to plant diascia by using the USDA zone info.

Planting Calendar for Diascia

Frost tolerance for diascia:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since diascia are moderately cold tolerant you can plant them a little bit earlier in the year than more sensitive plants.

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

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

Last Frost Date

In Romeoville the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Romeoville is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Romeoville last frost occurs after April 15 be ready to cover your diascia if you have a 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.