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.

It's possible to figure out when it's possible to plant sunflowers by referring to the USDA zone info for Crystal Lake.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After the last frost.

You really shouldn't plant sunflowers until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant sunflowers in Crystal Lake is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant sunflowers and expect a good harvest is probably August. If you wait any later than that and your sunflowers may not have a chance to grow to maturity. If you are starting your sunflowers indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Crystal Lake. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Crystal Lake is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Crystal Lake you get a frost after April 15 be ready to protect your sunflowers if you have a surprise late frost.

USDA Zone Info for Crystal Lake

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 Crystal Lake

You may be interested in your other planting guides for Crystal Lake.