The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of making a decision about when it's the best time to plant sunflowers is to refer to the USDA zone info for Richland.

Planting Calendar for Sunflowers

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

You should not 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 Richland 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. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

The average date of last frost is March 15 in Richland. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Richland is not always accurate the actual date of last frost is different every year. Half of the time in Richland you get surprised by a frost after March 15 so make sure that you are prepared to cover your sunflowers if you have a late frost.

USDA Zone Info for Richland

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 Richland

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