When to Plant Impatiens 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 impatiens in Hamilton can be estimated by using the USDA zone info.


Planting Calendar for Impatiens

Frost tolerance for impatiens: Not tolerant of frost.
When to plant: After the last frost.

It's probably a bad idea to plant impatiens until after the last frost when the weather gets warmer because they are not cold tolerant.

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

The earliest that you can plant impatiens in Hamilton is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant impatiens and expect a good harvest is probably August. You probably don't want to wait any later than that or else your impatiens may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your impatiens indoors.

Last Frost Date

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

Since the USDA zone info for Hamilton is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Hamilton you get surprised by a frost after April 15 be ready to cover your impatiens in the event of a 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.