The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when to plant spinach is to look at the USDA zone info for Helena.

Planting Calendar for Spinach

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

Since spinach are moderately cold tolerant you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant spinach in Helena 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 spinach and expect a good harvest is probably September. You probably don't want to wait any later than that or else your spinach may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your spinach indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Helena. In the coldest months of winter you should expect an average low temperature of 10°F.

Always 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 Helena and it will vary from year to year. Half of the time in Helena there is a last frost after March 15 so make sure that you are prepared to protect your spinach if you have 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.