Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Riverton can be reviewed to estimate when to plant twinspur.

Planting Calendar for Twinspur

Frost tolerance for twinspur:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Twinspur do ok in mild cold which means that you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant twinspur in Riverton is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant twinspur and expect a good harvest is probably August. You probably don't want to wait any later than that or else your twinspur may not have a chance to really do well. Starting your twinspur indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Riverton. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Riverton is just an average the actual date of last frost is different every year. Since half of the time in Riverton it frosts late in the year after May 15 be ready to cover your twinspur if you have a late frost.

USDA Zone Info for Riverton

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Riverton

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