One of the best tools that you have as gardeners to help us determine 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.

One way of making a decision about when to plant digitalis is to consult the USDA zone info for Thornton.

Planting Calendar for Digitalis

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

Digitalis do ok in moderate cold which means that you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant digitalis in Thornton 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 digitalis and expect a good harvest is probably September. You probably don't want to wait any later than that or else your digitalis may not have a chance to really do well. If you are starting your digitalis 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.

Remember that USDA zone info for Thornton is just an average and the actual date of last frost will vary from year to year. Since half of the time in Thornton it frosts late in the year after April 15 be ready to protect your digitalis if you have a surprise 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.