Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 you can plant purslane is to check out the USDA zone info for Boulder.

Planting Calendar for Purslane

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

Since purslane are barely cold tolerant you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant purslane in Boulder 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 purslane and expect a good harvest is probably August. If you wait any later than that and your purslane may not have a chance to really do well. If you are starting your purslane indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Boulder. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Boulder may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Boulder last frost occurs after April 15 be ready to cover your purslane if you have a surprise 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.