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

You should be able to determine when it's possible to plant oxalis by referring to the USDA zone info for Surprise.

Planting Calendar for Oxalis

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

Oxalis require warm weather which means that it's important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant oxalis in Surprise 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. If you wait any later than that and your oxalis may not have a chance to really do well. You can get started a couple of weeks earlier by starting your oxalis indoors.

Last Frost Date

The average date of last frost is February 15 in Surprise. It might get as low as 25°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Surprise and it changes from year to year. Half of the time in Surprise there is a last frost after February 15 so make sure that you are prepared to cover your oxalis if you have a late frost.

USDA Zone Info for Surprise

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 Surprise

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