One of the best tools that you have as gardeners to help us determine 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 Sulphur you can figure out when it's possible to plant yarrow by looking at the USDA zone info.

Planting Calendar for Yarrow

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

Yarrow do well in pretty solid cold which means that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant yarrow in Sulphur 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 yarrow and expect a good harvest is probably September. Any later than that and your yarrow may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your yarrow indoors.

Last Frost Date

In Sulphur the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Remember that USDA zone info for Sulphur is just an average and the actual date of last frost will vary from year to year. Half of the time in Sulphur there is a last frost after April 15 so make sure that you are ready to protect your yarrow if you have a surprise late frost.

USDA Zone Info for Sulphur

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Sulphur

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