The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's the best time to plant oxalis in Ottawa by checking out the USDA zone info.

Planting Calendar for Oxalis

Frost tolerance for oxalis:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's a bad idea to plant oxalis until after the last frost because they require warm weather.

The earliest that you can plant oxalis in Ottawa is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant oxalis and expect a good harvest is probably August. If you wait any later than that and your oxalis may not have a chance to grow to maturity. Starting your oxalis indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Ottawa. You can expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ottawa and it will vary from year to year. Since half of the time in Ottawa it frosts late in the year after April 15 be ready to cover your oxalis in the event of one of those late frosts.

USDA Zone Info for Ottawa

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 Ottawa

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