Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when to plant gladiolus is to examine the USDA zone info for Colby.

Planting Calendar for Gladiolus

Frost tolerance for gladiolus:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Gladiolus tend to make it in mild cold which means that you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

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

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

Last Frost Date

The average date of last frost is April 15 in Colby. You can expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Colby is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Colby last frost occurs after April 15 be ready to protect your gladiolus 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.