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

The first chance to plant gladiolus in Ontario should be figured out by using the USDA zone info.

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 one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

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

The last month that you can plant gladiolus and expect a good harvest is probably September. Any later than that and your gladiolus may not have a chance to fully mature. You can get started a few weeks earlier by starting your gladiolus indoors.

Last Frost Date

The average date of last frost is January 31 in Ontario. In the coldest months of winter you should expect an average low temperature of 30°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Ontario and it changes from year to year. Since half of the time in Ontario there is a last frost after January 31 be ready to protect your gladiolus if you have a surprise late frost.

USDA Zone Info for Ontario

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Ontario

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