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When to Plant Napa Valley Fern in Lewistown, MT

Before planting it is a good idea to find your USDA Zone info to determine 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.

A way of making a decision about when you can plant napa valley fern is to consult the USDA zone info for Lewistown.


Planting Calendar for Napa Valley Fern

Frost tolerance for napa valley fern: Not tolerant of frost.
When to plant: After the last frost has passed.

It's probably not a good idea to plant napa valley fern until after all chance of frost has passed because they are not cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant napa valley fern
Possibly ok, but a risky time to plant napa valley fern
Probably not a good time to plant napa valley fern

The earliest that you can plant napa valley fern in Lewistown 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 napa valley fern and expect a good harvest is probably August. You probably don't want to wait any later than that or else your napa valley fern may not have a chance to grow to maturity. If you are starting your napa valley fern indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Lewistown. In the coldest months of winter you can expect an average low temperature of -30°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Lewistown and it is different every year. Half of the time in Lewistown last frost occurs after May 15 so just be sure to be ready to cover your napa valley fern if you have one of those late frosts.

USDA Zone Info for Lewistown

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-30°F
Highest Expected Low-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Lewistown

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