One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to figure out when it's possible to plant myosotis by reviewing the USDA zone info for Thornton.

Planting Calendar for Myosotis

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

Myosotis do ok in mild cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

On average the last frost is on 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 just an average the actual date of last frost changes from year to year. Since half of the time in Thornton you get a frost after April 15 be ready to protect your myosotis 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.