One of the first steps you take when you are determining 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.

By looking at the USDA zone info for Riverdale it's a good idea to estimate when 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 moderately cold tolerant you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant hollyhocks in Riverdale 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. If you wait any later than that and your hollyhocks may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your hollyhocks indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Riverdale. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Riverdale is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Riverdale there is a last frost after April 15 be ready to cover your hollyhocks in the event of a late frost.

USDA Zone Info for Riverdale

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Riverdale

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