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

You should be able to figure out when to plant portulaca by looking at the USDA zone info for Mount Vernon.

Planting Calendar for Portulaca

Frost tolerance for portulaca:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably a bad idea to plant portulaca until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant portulaca in Mount Vernon 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 portulaca and expect a good harvest is probably August. If you wait any later than that and your portulaca may not have a chance to really do well. Starting your portulaca indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Mount Vernon the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -10°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Mount Vernon and it will vary from year to year. Half of the time in Mount Vernon it frosts late in the year after April 15 so make sure that you are ready to cover your portulaca in the event of a late frost.

USDA Zone Info for Mount Vernon

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Mount Vernon

You may be interested in your other planting guides for Mount Vernon.