Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant santolina in Helena can be estimated by using the USDA zone info.

Planting Calendar for Santolina

Frost tolerance for santolina:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Santolina do well in a bit of cold which means that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant santolina 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 santolina and expect a good harvest is probably August. If you wait any later than that and your santolina may not have a chance to grow to maturity. Starting your santolina indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Helena. It might get as low as -25°F during the coldest months of winter.

Keep in mind that USDA zone info for Helena is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Helena you get a frost after May 15 be ready to cover your santolina if you have one of those late frosts.

USDA Zone Info for Helena

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Helena

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