One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Colby you can estimate when it's the best time to plant calla lily by checking out the USDA zone info.

Planting Calendar for Calla Lily

Frost tolerance for calla lily:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You really shouldn't plant calla lily until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant calla lily in Colby 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 calla lily and expect a good harvest is probably August. Any later than that and your calla lily may not have a chance to grow to maturity. Starting your calla lily indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Colby and it can change quite a bit from year to year. Since half of the time in Colby you get a frost after April 15 be ready to cover your calla lily if you have a late frost.

USDA Zone Info for Colby

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Colby

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