One of the first steps you take when you are determining your gardening schedule is find your 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 Harlingen should be used to figure out when it's a good idea to plant xerianthemum.

Planting Calendar for Xerianthemum

Frost tolerance for xerianthemum:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Xerianthemum tend to make it in some cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant xerianthemum in Harlingen is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant xerianthemum and expect a good harvest is probably September. If you wait any later than that and your xerianthemum may not have a chance to fully mature. If you are starting your xerianthemum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Harlingen and it changes from year to year. Since half of the time in Harlingen it frosts late in the year after February 15 be ready to cover your xerianthemum in the event of a surprise late frost.

USDA Zone Info for Harlingen

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 Harlingen

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