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.

In Joshua you can estimate when you can plant centaurea by using the USDA zone info.

Planting Calendar for Centaurea

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

Centaurea do ok in moderate cold which means that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant centaurea in Joshua 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 centaurea and expect a good harvest is probably September. Any later than that and your centaurea may not have a chance to really do well. Starting your centaurea indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Joshua. It might get as low as 10°F during the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Joshua and it can change quite a bit from year to year. Since half of the time in Joshua there is a last frost after March 15 be ready to protect your centaurea in the event of one of those late frosts.

USDA Zone Info for Joshua

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Joshua

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