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.

The best time to plant asters in Estes Park should be figured out by looking at the USDA zone info.

Planting Calendar for Asters

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

Asters are moderately cold tolerant which tells us that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant asters in Estes Park 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 asters and expect a good harvest is probably September. If you wait any later than that and your asters may not have a chance to really do well. If you are starting your asters 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 when the weather gets warmer is on April 15 in Estes Park. You should expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that USDA zone info for Estes Park is not always accurate and the actual date of last frost changes from year to year. Half of the time in Estes Park you get surprised by a frost after April 15 so always be ready to protect your asters in the event of one of those late frosts.

USDA Zone Info for Estes Park

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 Estes Park

You may be interested in your other planting guides for Estes Park.