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.

By referring to the USDA zone info for Knightdale it's a good idea to determine when it's a good idea to plant helianthemum.

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 moderately cold tolerant you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant helianthemum in Knightdale 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. You can get started a few weeks earlier by starting your helianthemum indoors.

Last Frost Date

The average date of last frost is April 15 in Knightdale. You should expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Knightdale is just an average the actual date of last frost will vary from year to year. Half of the time in Knightdale there is a last frost after April 15 so make sure that you are prepared to protect your helianthemum in the event of a surprise late frost.

USDA Zone Info for Knightdale

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Knightdale

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