The USDA Zone info is a great tool for gardeners to help us estimate 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.

You will be able to figure out when to plant hardy asters by reviewing the USDA zone info for Middleton.

Planting Calendar for Hardy Asters

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

Since hardy asters are barely cold tolerant you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant hardy asters in Middleton 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 hardy asters and expect a good harvest is probably August. If you wait any later than that and your hardy asters may not have a chance to really do well. You can get started a couple of weeks earlier by starting your hardy asters indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Middleton. In the coldest months of winter you should expect an average low temperature of -20°F.

It's important to remember that USDA zone info for Middleton may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Middleton it frosts late in the year after April 15 so just be sure to be ready to protect your hardy asters in the event of a late frost.

USDA Zone Info for Middleton

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 Middleton

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