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When to Plant Sweet Williams in Missoula, MT

One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when it's a good idea to plant sweet williams is to refer to the USDA zone info for Missoula.

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Planting Calendar for Sweet Williams

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

Sweet Williams are moderately cold tolerant which tells us that you can plant them earlier than plants that are more sensitive to the cold.

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

The earliest that you can plant sweet williams in Missoula 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 sweet williams and expect a good harvest is probably September. Any later than that and your sweet williams may not have a chance to fully mature. If you are starting your sweet williams indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Missoula. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Missoula and it is different every year. Half of the time in Missoula you get a frost after April 15 so make sure that you are prepared to cover your sweet williams if you have one of those late frosts.

USDA Zone Info for Missoula

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 Missoula

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