One of the first steps you take when you are getting a good idea 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.

A way of figuring out when you can plant sunflowers is to consult the USDA zone info for Caldwell.

Planting Calendar for Sunflowers

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

Sunflowers require warm weather which tells us that you really should wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant sunflowers in Caldwell 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 couple of weeks earlier.

Last Frost Date

In Caldwell the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Caldwell is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Caldwell it frosts late in the year after April 15 be ready to cover your sunflowers if you have one of those late frosts.

USDA Zone Info for Caldwell

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 Caldwell

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