One of the first steps you take when you are figuring out 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.

One way of determining when to plant helianthemum is to use the USDA zone info for Oak Harbor.

Planting Calendar for Helianthemum

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

Since helianthemum are one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant helianthemum in Oak Harbor 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 helianthemum and expect a good harvest is probably September. If you wait any later than that and your helianthemum may not have a chance to fully mature. You can get started a few weeks earlier by starting your helianthemum indoors.

Last Frost Date

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

Since the USDA zone info for Oak Harbor is not always accurate the actual date of last frost will vary from year to year. Half of the time in Oak Harbor last frost occurs after March 15 so make sure that you are prepared to protect your helianthemum if you have a surprise late frost.

USDA Zone Info for Oak Harbor

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 Oak Harbor

You may be interested in your other planting guides for Oak Harbor.