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.

By using the USDA zone info for San Juan you should be able to determine when it's the best time to plant chrysanthemum.

Planting Calendar for Chrysanthemum

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

Since chrysanthemum do not do well in cold weather it's important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant chrysanthemum 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 chrysanthemum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your chrysanthemum may not have a chance to fully mature. If you are starting your chrysanthemum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In San Juan the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

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 you get a frost after February 15 so just be sure to be ready to cover your chrysanthemum if you have 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.