One of the first steps you take when you are estimating your gardening schedule is find your 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.

The USDA zone info for Palo Alto should be reviewed to determine when it's the best time to plant purple coneflower.

Planting Calendar for Purple Coneflower

Frost tolerance for purple coneflower:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since purple coneflower are barely cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant purple coneflower in Palo Alto 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 purple coneflower and expect a good harvest is probably September. If you wait any later than that and your purple coneflower may not have a chance to grow to maturity. If you are starting your purple coneflower indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Palo Alto. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Palo Alto is an average the actual date of last frost will vary from year to year. Since half of the time in Palo Alto there is a last frost after February 15 be ready to cover your purple coneflower in the event of a surprise late frost.

USDA Zone Info for Palo Alto

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Palo Alto

You may be interested in your other planting guides for Palo Alto.