Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Lock Haven you should be able to estimate when to plant sunflowers.

Planting Calendar for Sunflowers

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

It's not a good idea to plant sunflowers until after all chance of frost has passed because they require warm weather.

The earliest that you can plant sunflowers in Lock Haven 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. You probably don't want to wait any later than that or else your sunflowers may not have a chance to really do well. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

The average date of last frost is April 15 in Lock Haven. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Lock Haven is just an average the actual date of last frost changes from year to year. Half of the time in Lock Haven it frosts late in the year after April 15 so always be ready to cover your sunflowers in the event of a surprise late frost.

USDA Zone Info for Lock Haven

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Lock Haven

You may be interested in your other planting guides for Lock Haven.