Before planting it is a good idea to find your USDA Zone info to estimate 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 Portland can be looked at to determine when it's possible to plant melampodium.

Planting Calendar for Melampodium

Frost tolerance for melampodium:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since melampodium require warm weather it is necessary to wait until after the last frost before you can plant them.

The earliest that you can plant melampodium 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 melampodium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your melampodium may not have a chance to grow to maturity. If you are starting your melampodium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Portland. You should expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Portland is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Portland last frost occurs after April 15 so make sure that you are ready to protect your melampodium if you have one of those late frosts.

USDA Zone Info for Portland

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Portland

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