The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant creeping zinnia in Helena can be figured out by checking out the USDA zone info.

Planting Calendar for Creeping Zinnia

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

Creeping Zinnia tend to make it in a tiny bit of cold which means that you can plant them a bit earlier in the year than other frost tender plants.

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

The last month that you can plant creeping zinnia and expect a good harvest is probably August. If you wait any later than that and your creeping zinnia may not have a chance to grow to maturity. If you are starting your creeping zinnia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Helena. It might get as low as 10°F during the coldest months of winter.

It's important to remember 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 Helena and it is different every year. Half of the time in Helena you get surprised by a frost after March 15 so always be ready to protect your creeping zinnia in the event of one of those late frosts.

USDA Zone Info for Helena

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 Helena

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