One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

By using the USDA zone info for Silvis you will be able to determine when it's possible to plant trailing portulaca.

Planting Calendar for Trailing Portulaca

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

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

The earliest that you can plant trailing portulaca in Silvis 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 trailing portulaca and expect a good harvest is probably August. If you wait any later than that and your trailing portulaca may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your trailing portulaca indoors.

Last Frost Date

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

Remember that USDA zone info for Silvis is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Silvis there is a last frost after April 15 be ready to protect your trailing portulaca in the event of one of those late frosts.

USDA Zone Info for Silvis

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 Silvis

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