One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

The first chance to plant sweet sultan in Portland should be figured out by referring to the USDA zone info.

Planting Calendar for Sweet Sultan

Frost tolerance for sweet sultan:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Sweet Sultan are barely cold tolerant which tells us that you can start planting them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant sweet sultan 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 sweet sultan and expect a good harvest is probably August. Any later than that and your sweet sultan may not have a chance to really do well. If you are starting your sweet sultan indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Portland. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Portland may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Portland last frost occurs after April 15 be ready to cover your sweet sultan if you have a surprise late frost.

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.