The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In San Juan you can estimate when you can plant zinnia by referring to the USDA zone info.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost.

Since zinnia require warm weather you have to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant zinnia 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 zinnia and expect a good harvest is probably September. Any later than that and your zinnia may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your zinnia indoors.

Last Frost Date

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

Since the USDA zone info for San Juan is an average the actual date of last frost can change quite a bit from year to year. Half of the time in San Juan there is a last frost after February 15 so just be sure to be ready to protect your zinnia in the event of one of those late frosts.

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.