The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of figuring out when it's a good idea to plant hardy hibiscus is to refer to the USDA zone info for Lowell.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant hardy hibiscus earlier in the year because they are very cold tolerant.

The earliest that you can plant hardy hibiscus in Lowell 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 hardy hibiscus and expect a good harvest is probably September. If you wait any later than that and your hardy hibiscus may not have a chance to really do well. If you are starting your hardy hibiscus indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Lowell. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Lowell is just an average the actual date of last frost changes from year to year. Half of the time in Lowell you get a frost after April 15 so always be ready to cover your hardy hibiscus in the event of a late frost.

USDA Zone Info for Lowell

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 Lowell

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