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.

In South Houston you can estimate when it's the best time to plant primroses by reviewing the USDA zone info.

Planting Calendar for Primroses

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

Primroses can survive in pretty solid cold which means that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant primroses in South Houston 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 primroses and expect a good harvest is probably October. You probably don't want to wait any later than that or else your primroses may not have a chance to grow to maturity. You can get started a little bit earlier by starting your primroses indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in South Houston. It might get as low as 20°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 South Houston and it is different every year. Half of the time in South Houston you get a frost after February 15 so just be sure to be ready to cover your primroses in the event of a late frost.

USDA Zone Info for South Houston

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 South Houston

You may be interested in your other planting guides for South Houston.