When to Plant Penstemon in Hamilton, MT

The USDA Zone info is a great tool for gardeners to help us figure out 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 first chance to plant penstemon in Hamilton can be estimated by looking at the USDA zone info.


Planting Calendar for Penstemon

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

You can plant penstemon a little bit earlier in the year because they do well in moderate cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant penstemon
Possibly ok, but a risky time to plant penstemon
Probably not a good time to plant penstemon

The earliest that you can plant penstemon in Hamilton 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 penstemon and expect a good harvest is probably September. If you wait any later than that and your penstemon may not have a chance to grow to maturity. You can get started a little bit earlier by starting your penstemon indoors.

Last Frost Date

In Hamilton the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Hamilton and it is different every year. Half of the time in Hamilton it frosts late in the year after April 15 so make sure that you are prepared to protect your penstemon if you have a surprise late frost.

USDA Zone Info for Hamilton

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 Hamilton

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