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

A way of making a decision about when it's the best time to plant primula is to examine the USDA zone info for Port Arthur.

Planting Calendar for Primula

Frost tolerance for primula:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Primula are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant primula in Port Arthur 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 primula and expect a good harvest is probably October. If you wait any later than that and your primula may not have a chance to fully mature. Starting your primula indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Port Arthur. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Port Arthur is an average and the actual date of last frost is different every year. Since half of the time in Port Arthur it frosts late in the year after February 15 be ready to protect your primula if you have a surprise late frost.

USDA Zone Info for Port Arthur

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Port Arthur

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