One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to estimate when it's a good idea to plant asters by looking at the USDA zone info for Belfast.

Planting Calendar for Asters

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

Asters tend to make it in a little bit of cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant asters in Belfast 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. You can get started a couple of weeks earlier by starting your asters indoors.

Last Frost Date

The average date of last frost is April 15 in Belfast. In the coldest months of winter you can expect an average low temperature of -15°F.

Remember that USDA zone info for Belfast is just an average and the actual date of last frost changes from year to year. Half of the time in Belfast there is a last frost after April 15 so make sure that you are ready to cover your asters if you have a surprise late frost.

USDA Zone Info for Belfast

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 Belfast

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