One of the best tools that you have as gardeners to help us estimate 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.

The USDA zone info for Boston can be reviewed to figure out when it's a good idea to plant oxalis.

Planting Calendar for Oxalis

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

It's probably not a good idea to plant oxalis until after the last frost because they require warm weather.

The earliest that you can plant oxalis in Boston 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 really do well. You can get started a little bit earlier by starting your oxalis indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Boston. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for Boston is an average the actual date of last frost will vary from year to year. Half of the time in Boston there is a last frost after April 15 so make sure that you are ready to protect your oxalis in the event of a surprise late frost.

USDA Zone Info for Boston

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Boston

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