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.

By looking at the USDA zone info for Hillsborough you will be able to estimate when 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.

You can plant asters a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant asters in Hillsborough 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. Starting your asters indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Hillsborough. It might get as low as 5°F during the coldest months of winter.

Since the USDA zone info for Hillsborough is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Hillsborough you get a frost after April 15 be ready to cover your asters in the event of a late frost.

USDA Zone Info for Hillsborough

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Hillsborough

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