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.

You can determine when to plant gomphrena in Duluth by looking at the USDA zone info.

Planting Calendar for Gomphrena

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

Gomphrena tend to make it in mild cold which tells us that you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant gomphrena in Duluth 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 gomphrena and expect a good harvest is probably August. Any later than that and your gomphrena may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your gomphrena indoors.

Last Frost Date

In Duluth the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -30°F.

It's important to remember 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 Duluth and it is different every year. Since half of the time in Duluth it frosts late in the year after May 15 be ready to protect your gomphrena in the event of one of those late frosts.

USDA Zone Info for Duluth

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

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

Plants to Grow in Duluth

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