The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when you can plant hollyhocks is to refer to the USDA zone info for Green River.

Planting Calendar for Hollyhocks

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

Since hollyhocks do well in moderate cold you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hollyhocks in Green River is March. However, you really should wait until April if you don't want to take any chances.

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

Last Frost Date

In Green River the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Green River is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Green River it frosts late in the year after May 15 be ready to protect your hollyhocks in the event of a surprise late frost.

USDA Zone Info for Green River

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Green River

You may be interested in your other planting guides for Green River.