One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Rock Springs you will be able to determine when it's possible to plant lupine.

Planting Calendar for Lupine

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

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

The earliest that you can plant lupine in Rock Springs 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 lupine and expect a good harvest is probably September. You probably don't want to wait any later than that or else your lupine may not have a chance to grow to maturity. Starting your lupine indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Rock Springs the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Rock Springs may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Rock Springs you get surprised by a frost after April 15 be ready to cover your lupine in the event of a surprise late frost.

USDA Zone Info for Rock Springs

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 Rock Springs

You may be interested in your other planting guides for Rock Springs.