When to Plant Nasturtium in Portland, ME

One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Portland it's possible to determine when you can plant nasturtium.


Planting Calendar for Nasturtium

Frost tolerance for nasturtium: Not tolerant of frost.
When to plant: After all chance of frost has passed.

Since nasturtium are not cold tolerant you have to wait until after the last frost when the weather gets warmer before you can plant them.

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

The earliest that you can plant nasturtium in Portland 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 nasturtium and expect a good harvest is probably August. If you wait any later than that and your nasturtium may not have a chance to grow to maturity. Starting your nasturtium indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Portland is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Portland it frosts late in the year after April 15 be ready to protect your nasturtium in the event of one of those late frosts.

USDA Zone Info for 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 Portland

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