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.

In Thornton you can determine when it's the best time to plant geum by using the USDA zone info.

Planting Calendar for Geum

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

Geum do ok in moderate cold which tells us that you can get them planted just a bit earlier than other plants that might not handle the cold.

The earliest that you can plant geum 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 geum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your geum may not have a chance to grow to maturity. If you are starting your geum indoors then you might be able to get away with starting them a few weeks earlier.

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.

It's important to remember that USDA zone info for Thornton is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Thornton you get surprised by a frost after April 15 so make sure that you are prepared to cover your geum 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.