When to Plant Hollyhocks in Silvis, IL

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Silvis should be looked at to figure out when it's possible to plant hollyhocks.


Planting Calendar for Hollyhocks

Frost tolerance for hollyhocks: Tolerant of some frost.
When to plant: Up to 5 weeks before last frost.

Since hollyhocks are one of those plants that can tolerate a little bit of cold weather you can plant them a little earlier in the year than plants that are more sensitive to the cold.

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

The earliest that you can plant hollyhocks 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 hollyhocks and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hollyhocks may not have a chance to really do well. If you are starting your hollyhocks indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Silvis the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Silvis and it can change quite a bit from year to year. Half of the time in Silvis there is a last frost after April 15 so just be sure to be ready to protect your hollyhocks 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.