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.

It's possible to determine when it's a good idea to plant hardy hibiscus by reviewing the USDA zone info for Silvis.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since hardy hibiscus do well in cold you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant hardy hibiscus in Silvis is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant hardy hibiscus and expect a good harvest is probably September. If you wait any later than that and your hardy hibiscus may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your hardy hibiscus indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Silvis. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Silvis 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 Silvis you get a frost after April 15 be ready to protect your hardy hibiscus in the event of a late frost.

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.