One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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 to plant gladiolus is to check out the USDA zone info for Olean.

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 can survive in mild cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant gladiolus in Olean 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 grow to maturity. If you are starting your gladiolus indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Olean. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Olean is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Olean there is a last frost after April 15 so always be ready to protect your gladiolus in the event of one of those late frosts.

USDA Zone Info for Olean

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Olean

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