When to Plant Gladiolus in Carbondale, CO

One of the first steps you take when you are determining 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.

By using the USDA zone info for Carbondale it's a good idea to determine when you can plant gladiolus.


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 a tiny bit of cold which tells us that you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant gladiolus
Possibly ok, but a risky time to plant gladiolus
Probably not a good time to plant gladiolus

The earliest that you can plant gladiolus in Carbondale 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. If you wait any later than that and your gladiolus may not have a chance to really do well. If you are starting your gladiolus indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Carbondale. It might get as low as -15°F during the coldest months of winter.

It's important to remember that USDA zone info for Carbondale is not always accurate and the actual date of last frost is different every year. Since half of the time in Carbondale you get a frost after April 15 be ready to cover your gladiolus in the event of a surprise late frost.

USDA Zone Info for Carbondale

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 Carbondale

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