One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

You should be able to estimate when it's possible to plant asters by referring to the USDA zone info for South Portland.

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 some cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant asters in South Portland 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. Any later than that and your asters may not have a chance to fully mature. You can get started a few weeks earlier by starting your asters indoors.

Last Frost Date

In South Portland the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Always keep in mind that USDA zone info for South Portland may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in South Portland it frosts late in the year after April 15 be ready to protect your asters if you have one of those late frosts.

USDA Zone Info for South Portland

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 South Portland

You may be interested in your other planting guides for South Portland.