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.

The earliest that you can plant alstromeria in Ontario should be determined by referring to the USDA zone info.

Planting Calendar for Alstromeria

Frost tolerance for alstromeria:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Alstromeria do ok in mild cold which means that you can plant them just a bit earlier in the year than other frost tender plants.

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

The last month that you can plant alstromeria and expect a good harvest is probably October. Any later than that and your alstromeria may not have a chance to fully mature. If you are starting your alstromeria indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Ontario the average date of last frost happens on January 31. You can expect an average low temperature of 30°F in the coldest months of winter.

It's important to remember that USDA zone info for Ontario is just an average and the actual date of last frost is different every year. Since half of the time in Ontario it frosts late in the year after January 31 be ready to cover your alstromeria in the event of one of those late frosts.

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.