One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

It's a good idea to figure out when it's the best time to plant monkey flower by referring to the USDA zone info for Helena.

Planting Calendar for Monkey Flower

Frost tolerance for monkey flower:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Monkey Flower require warm weather 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 monkey flower in Helena is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant monkey flower and expect a good harvest is probably August. Any later than that and your monkey flower may not have a chance to grow to maturity. You can get started a little bit earlier by starting your monkey flower indoors.

Last Frost Date

In Helena the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Helena is just an average the actual date of last frost is different every year. Since half of the time in Helena there is a last frost after May 15 be ready to protect your monkey flower in the event of 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.