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 Urbana you can estimate when to plant helianthemum by checking out the USDA zone info.

Planting Calendar for Helianthemum

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

You can plant helianthemum a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant helianthemum in Urbana 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 helianthemum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your helianthemum may not have a chance to really do well. Starting your helianthemum indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Urbana. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Urbana may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Urbana it frosts late in the year after April 15 be ready to protect your helianthemum in the event of a late frost.

USDA Zone Info for Urbana

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Urbana

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