Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 Golden you will be able to determine when you can plant zinnia.

Planting Calendar for Zinnia

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

Zinnia are not cold tolerant which means that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant zinnia in Golden 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 really do well. You can get started a couple of weeks earlier by starting your zinnia indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Golden. You can expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Golden and it can change quite a bit from year to year. Half of the time in Golden there is a last frost after April 15 so always be ready to cover your zinnia if you have a late frost.

USDA Zone Info for Golden

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 Golden

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