The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's a good idea to plant rhubarb in South Portland by looking at the USDA zone info.

Planting Calendar for Rhubarb

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

Rhubarb do well in moderate cold which tells us that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant rhubarb 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 rhubarb and expect a good harvest is probably September. Any later than that and your rhubarb may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your rhubarb indoors.

Last Frost Date

The average date of last frost is April 15 in South Portland. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for South Portland is just an average 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 rhubarb in the event of 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.