One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

The earliest that you can plant alstromeria in Spearfish can be estimated by checking out the USDA zone info.

Planting Calendar for Alstromeria

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

You can plant alstromeria just a bit earlier in the year because they are moderately cold tolerant.

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

The last month that you can plant alstromeria and expect a good harvest is probably September. Any later than that and your alstromeria may not have a chance to really do well. Starting your alstromeria indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Spearfish is an average the actual date of last frost is different every year. Since half of the time in Spearfish it frosts late in the year after April 15 be ready to cover your alstromeria in the event of a late frost.

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.