One of the first steps you take when you are determining 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.

One way of determining when it's possible to plant sunflowers is to examine the USDA zone info for Thomson.

Planting Calendar for Sunflowers

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

It's not a good idea to plant sunflowers until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant sunflowers in Thomson 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. Any later than that and your sunflowers may not have a chance to really do well. 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

On average the last frost has passed is on March 15 in Thomson. You can expect an average low temperature of 10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Thomson 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 Thomson you get a frost after March 15 be ready to cover your sunflowers in the event of a surprise late frost.

USDA Zone Info for Thomson

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Thomson

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