When to Plant Portulaca in Harlan, IA

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.

The earliest that you can plant portulaca in Harlan should be figured out by referring to 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.

Portulaca require warm weather which tells us that you have to wait until it warms up after all chance of frost has passed before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant portulaca
Possibly ok, but a risky time to plant portulaca
Probably not a good time to plant portulaca

The earliest that you can plant portulaca in Harlan 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. Any later than that and your portulaca may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your portulaca indoors.

Last Frost Date

In Harlan the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Harlan is an average the actual date of last frost will vary from year to year. Since half of the time in Harlan you get surprised by a frost after April 15 be ready to cover your portulaca in the event of a surprise late frost.

USDA Zone Info for Harlan

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Harlan

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