One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Thornton you should be able to determine when it's the best time to plant swan river daisy.

Planting Calendar for Swan River Daisy

Frost tolerance for swan river daisy:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since swan river daisy do not do well in cold weather you need to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant swan river daisy in Thornton 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 swan river daisy and expect a good harvest is probably August. Any later than that and your swan river daisy may not have a chance to really do well. You can get started a few weeks earlier by starting your swan river daisy indoors.

Last Frost Date

The average date of last frost is April 15 in Thornton. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Thornton is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Thornton you get a frost after April 15 be ready to cover your swan river daisy if you have 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.