One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's the best time to plant sunflowers in Campbell by referring to the USDA zone info.

Planting Calendar for Sunflowers

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

Sunflowers do not do well in cold weather which tells us that you must 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 Campbell 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 little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Campbell. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Campbell may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Campbell 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 Campbell

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 Campbell

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