One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

One way of figuring out when it's the best time to plant gladiolus is to refer to the USDA zone info for Missoula.

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.

Since gladiolus are barely cold tolerant 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 Missoula 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. You can get started a couple of weeks earlier by starting your gladiolus indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Missoula. It might get as low as -15°F during the coldest months of winter.

It's important to remember that USDA zone info for Missoula is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Missoula it frosts late in the year after April 15 so make sure that you are prepared to protect your gladiolus in the event of a surprise late frost.

USDA Zone Info for Missoula

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 Missoula

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