Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant dipladenia in Colby can be determined by looking at the USDA zone info.

Planting Calendar for Dipladenia

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

You can not plant dipladenia until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant dipladenia 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 dipladenia and expect a good harvest is probably August. If you wait any later than that and your dipladenia may not have a chance to fully mature. You can get started a few weeks earlier by starting your dipladenia indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Colby. In the coldest months of winter you can expect an average low temperature of -15°F.

It's important 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 is different every year. Half of the time in Colby it frosts late in the year after April 15 so always be ready to protect your dipladenia in the event of one of those late frosts.

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.