One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of making a decision about when it's a good idea to plant sedum is to examine the USDA zone info for Thornton.

Planting Calendar for Sedum

Frost tolerance for sedum:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

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

The earliest that you can plant sedum 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 sedum and expect a good harvest is probably September. If you wait any later than that and your sedum may not have a chance to fully mature. If you are starting your sedum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Thornton. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Thornton is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Thornton it frosts late in the year after April 15 so make sure that you are ready to cover your sedum 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.