When to Plant Cosmos in Milton, WI

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

In Milton you can determine when it's possible to plant cosmos by using the USDA zone info.


Planting Calendar for Cosmos

Frost tolerance for cosmos: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Since cosmos do ok in moderate cold you can plant them just a tiny bit earlier in the year than other frost tender plants.

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

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

The last month that you can plant cosmos and expect a good harvest is probably August. If you wait any later than that and your cosmos may not have a chance to really do well. You can get started a few weeks earlier by starting your cosmos indoors.

Last Frost Date

The average date of last frost is April 15 in Milton. You can expect an average low temperature of -20°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Milton and it changes from year to year. Half of the time in Milton last frost occurs after April 15 so always be ready to cover your cosmos in the event of a surprise late frost.

USDA Zone Info for Milton

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Milton

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