One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when to plant helianthemum is to look at the USDA zone info for Port Isabel.

Planting Calendar for Helianthemum

Frost tolerance for helianthemum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since helianthemum do well in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Port Isabel is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant helianthemum and expect a good harvest is probably October. You probably don't want to wait any later than that or else your helianthemum may not have a chance to really do well. Starting your helianthemum indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is January 31 in Port Isabel. It might get as low as 30°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Port Isabel and it is different every year. Since half of the time in Port Isabel you get a frost after January 31 be ready to cover your helianthemum if you have a surprise late frost.

USDA Zone Info for Port Isabel

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Port Isabel

You may be interested in your other planting guides for Port Isabel.