The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of determining when you can plant sanvitalia is to consult the USDA zone info for Thornton.

Planting Calendar for Sanvitalia

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

You can plant sanvitalia a bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant sanvitalia in Thornton 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 sanvitalia and expect a good harvest is probably August. If you wait any later than that and your sanvitalia may not have a chance to fully mature. If you are starting your sanvitalia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Thornton 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 Thornton is not always accurate the actual date of last frost changes from year to year. Since half of the time in Thornton it frosts late in the year after April 15 be ready to cover your sanvitalia in the event of a late frost.

USDA Zone Info for Thornton

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 Thornton

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