One of the best tools that you have as gardeners to help us estimate 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 calendula in Forest Grove can be estimated by checking out the USDA zone info.

Planting Calendar for Calendula

Frost tolerance for calendula:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Calendula are moderately cold tolerant which tells us that you can start planting them earlier than plants that are more sensitive to the cold.

The earliest that you can plant calendula in Forest Grove is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant calendula and expect a good harvest is probably September. If you wait any later than that and your calendula may not have a chance to grow to maturity. If you are starting your calendula 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 March 15 in Forest Grove. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Forest Grove is not always accurate the actual date of last frost will vary 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 cover your calendula 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.