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.

A common way of figuring out when it's possible to plant sunflowers is to check out the USDA zone info for Rupert.

Planting Calendar for Sunflowers

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

Sunflowers do not do well in cold weather which tells us that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant sunflowers in Rupert 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. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

In Rupert the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Rupert is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Rupert you get surprised by a frost after April 15 so make sure that you are prepared to protect your sunflowers in the event of one of those late frosts.

USDA Zone Info for Rupert

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 Rupert

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