One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Silvis it's possible to determine when you can plant violas.

Planting Calendar for Violas

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

Violas are one of those plants that can tolerate quite a bit of cold weather which means that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant violas 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 violas and expect a good harvest is probably September. Any later than that and your violas may not have a chance to grow to maturity. If you are starting your violas indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Silvis is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Silvis you get surprised by a frost after April 15 be ready to protect your violas 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.