When can I plant Helianthemum in Zone 4b

One of the first steps we take when we are determining our gardening schedule is find our USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

You should be able to determine when you can plant helianthemum by looking at the USDA zone info for Zone 4b.


Planting Calendar for Helianthemum

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

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant helianthemum
Possibly ok, but a risky time to plant helianthemum
Probably not a good time to plant helianthemum

The earliest that you can plant helianthemum in Zone 4b is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant helianthemum and expect a good harvest is probably August. If you wait any later than that and your helianthemum may not have a chance to grow to maturity. 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

The average date of last frost is May 15 in Zone 4b. We can expect an average low temperature of -25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Zone 4b is not always accurate and our actual date of last frost can change quite a bit from year to year. Since half of the time in Zone 4b we get surprised by a frost after May 15 be ready to protect your helianthemum in the event of one of those late frosts.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-25°F
Highest Expected Low-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in our other planting guides for Zone 4b.