One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Forest Grove you should be able to estimate when it's possible to plant dahlia.

Planting Calendar for Dahlia

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

It's probably a bad idea to plant dahlia until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant dahlia in Forest Grove 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. Any later than that and your dahlia may not have a chance to fully mature. If you are starting your dahlia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Forest Grove. It might get as low as 15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Forest Grove is not always accurate and the actual date of last frost changes from year to year. Half of the time in Forest Grove it frosts late in the year after March 15 so make sure that you are prepared to protect your dahlia if you have one of those late frosts.

USDA Zone Info for Forest Grove

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 Forest Grove

You may be interested in your other planting guides for Forest Grove.