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.

The USDA zone info for Portland should be looked at to determine when you can 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.

Since melampodium are not cold tolerant it's important to wait until after the last frost before you can plant them.

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

The last month that you can plant melampodium and expect a good harvest is probably September. Any later than that and your melampodium may not have a chance to really do well. You can get started a little bit earlier by starting your melampodium indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Portland. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Portland is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Portland there is a last frost after February 15 be ready to cover your melampodium if you have a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Portland

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