One of the best tools that you have as gardeners to help us figure out 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 reviewing the USDA zone info for South Houston you will be able to determine when it's the best time to plant pyrethrum.

Planting Calendar for Pyrethrum

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

Since pyrethrum are moderately cold tolerant you can plant them a little bit earlier in the year than other frost tender plants.

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

Last Frost Date

In South Houston the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 20°F.

Since the USDA zone info for South Houston may not be accurate from year to year the actual date of last frost is different every year. Half of the time in South Houston you get surprised by a frost after February 15 so always be ready to cover your pyrethrum in the event of a surprise 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.