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.

One way of figuring out when you can plant zinnia is to use the USDA zone info for Pleasant Hill.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably not a good idea to plant zinnia until after the last frost because they require warm weather.

The earliest that you can plant zinnia in Pleasant Hill is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant zinnia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your zinnia may not have a chance to grow to maturity. Starting your zinnia indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Pleasant Hill. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Pleasant Hill is just an average the actual date of last frost is different every year. Since half of the time in Pleasant Hill you get a frost after April 15 be ready to protect your zinnia in the event of one of those late frosts.

USDA Zone Info for Pleasant Hill

Here is the info for USDA Zone 5b.

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

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

Plants to Grow in Pleasant Hill

You may be interested in your other planting guides for Pleasant Hill.