One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. 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 you can plant sweet peas is to refer to the USDA zone info for Spearfish.

Planting Calendar for Sweet Peas

Frost tolerance for sweet peas:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Sweet Peas do well in very little cold which means that you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant sweet peas in Spearfish 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 sweet peas and expect a good harvest is probably August. Any later than that and your sweet peas may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your sweet peas indoors.

Last Frost Date

In Spearfish the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Keep in mind that USDA zone info for Spearfish may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Spearfish last frost occurs after April 15 so be sure to be ready to cover your sweet peas in the event of one of those late frosts.

USDA Zone Info for Spearfish

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Spearfish

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