One of the first steps you take when you are getting a good idea 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.

You can estimate when you can plant sweet potatos in Boulder by reviewing the USDA zone info.

Planting Calendar for Sweet Potatos

Frost tolerance for sweet potatos:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's a bad idea to plant sweet potatos until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant sweet potatos in Boulder 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 sweet potatos and expect a good harvest is probably August. Any later than that and your sweet potatos may not have a chance to fully mature. If you are starting your sweet potatos 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 Boulder. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Boulder is just an average the actual date of last frost will vary from year to year. Since half of the time in Boulder it frosts late in the year after April 15 be ready to cover your sweet potatos if you have a late frost.

USDA Zone Info for Boulder

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 Boulder

You may be interested in your other planting guides for Boulder.