One of the first steps you take when you are getting a good idea 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.

A way of determining when to plant helianthemum is to examine the USDA zone info for Bartlesville.

Planting Calendar for Helianthemum

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

Helianthemum can survive in mild cold which means that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Bartlesville 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. You probably don't want to wait any later than that or else your helianthemum may not have a chance to fully mature. If you are starting your helianthemum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Bartlesville. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that USDA zone info for Bartlesville may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Bartlesville you get surprised by a frost after April 15 be ready to cover your helianthemum if you have a late frost.

USDA Zone Info for Bartlesville

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Bartlesville

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