The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Markham you can estimate when it's a good idea to plant portulaca by reviewing the USDA zone info.

Planting Calendar for Portulaca

Frost tolerance for portulaca:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since portulaca are not cold tolerant you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant portulaca in Markham 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. You can get started a couple of weeks earlier by starting your portulaca indoors.

Last Frost Date

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

It's important to remember that USDA zone info for Markham is just an average and the actual date of last frost changes from year to year. Since half of the time in Markham there is a last frost after April 15 be ready to protect your portulaca if you have a surprise late frost.

USDA Zone Info for Markham

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 Markham

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