One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Owasso you should be able to figure out when it's a good idea to plant asters.

Planting Calendar for Asters

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

Asters do ok in mild cold which means that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant asters in Owasso 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 fully mature. 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

In Owasso the average date of last frost happens on April 15. You should expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Owasso is not always accurate the actual date of last frost will vary from year to year. Half of the time in Owasso last frost occurs after April 15 so always be ready to protect your asters in the event of a surprise late frost.

USDA Zone Info for Owasso

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Owasso

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