One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when it's a good idea to plant oxalis is to refer to the USDA zone info for Urbana.

Planting Calendar for Oxalis

Frost tolerance for oxalis:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since oxalis do not do well in cold weather you must wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant oxalis in Urbana 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. 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 Urbana. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Urbana may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Urbana last frost occurs after April 15 so make sure that you are ready to protect your oxalis if you have a late frost.

USDA Zone Info for Urbana

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 Urbana

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