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.

In Spearfish you can determine when it's possible to plant bougainvillea by using the USDA zone info.

Planting Calendar for Bougainvillea

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

Since bougainvillea are not cold tolerant it is important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant bougainvillea in Spearfish 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 bougainvillea and expect a good harvest is probably August. You probably don't want to wait any later than that or else your bougainvillea may not have a chance to grow to maturity. You can get started a little bit earlier by starting your bougainvillea indoors.

Last Frost Date

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

Just be sure to remember 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 it frosts late in the year after April 15 so be sure to be ready to cover your bougainvillea if you have a surprise 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.