The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Humboldt you can determine when it's a good idea to plant dahlia by using the USDA zone info.

Planting Calendar for Dahlia

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

You can not plant dahlia until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant dahlia in Humboldt 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 dahlia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlia may not have a chance to really do well. You can get started a little bit earlier by starting your dahlia indoors.

Last Frost Date

The average date of last frost is April 15 in Humboldt. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Humboldt may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Humboldt it frosts late in the year after April 15 be ready to protect your dahlia if you have a surprise late frost.

USDA Zone Info for Humboldt

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 Humboldt

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