Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Portland you should be able to determine when it's a good idea to plant melampodium.

Planting Calendar for Melampodium

Frost tolerance for melampodium:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You really shouldn't plant melampodium until after the last frost has passed because they require warm weather.

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 really do well. If you are starting your melampodium indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on March 15 in Portland. In the coldest months of winter you should expect an average low temperature of 15°F.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portland and it changes from year to year. Since half of the time in Portland there is a last frost after March 15 be ready to cover your melampodium in the event of a late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Portland

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