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

In San Juan you can determine when it's a good idea to plant oxalis by reviewing the USDA zone info.

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 are not cold tolerant.

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

The last month that you can plant oxalis and expect a good harvest is probably September. 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 few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in San Juan. You should expect an average low temperature of 25°F in the coldest months of winter.

Always keep in mind that USDA zone info for San Juan is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in San Juan last frost occurs after February 15 so make sure that you are ready to protect your oxalis in the event of a surprise late frost.

USDA Zone Info for San Juan

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in San Juan

You may be interested in your other planting guides for San Juan.