When to Plant Bougainvillea in Belfast, ME

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Belfast should be used to determine when it's a good idea to plant bougainvillea.


Planting Calendar for Bougainvillea

Frost tolerance for bougainvillea: Not tolerant of frost.
When to plant: After the last frost.

It's a bad idea to plant bougainvillea until after all chance of frost has passed because they require warm weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant bougainvillea
Possibly ok, but a risky time to plant bougainvillea
Probably not a good time to plant bougainvillea

The earliest that you can plant bougainvillea in Belfast is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant bougainvillea and expect a good harvest is probably August. If you wait any later than that and your bougainvillea may not have a chance to fully mature. If you are starting your bougainvillea indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Belfast. You can expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Belfast is not always accurate and the actual date of last frost is different every year. Since half of the time in Belfast there is a last frost after April 15 be ready to protect your bougainvillea if you have one of those late frosts.

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.