When to Plant Helianthemum in Glenwood, IA

One of the first steps you take when you are making a decision about your gardening schedule is find your 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 earliest that you can plant helianthemum in Glenwood should be estimated by checking out the USDA zone info.


Planting Calendar for Helianthemum

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

Since helianthemum do well in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

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 Glenwood 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 really do well. You can get started a little bit earlier by starting your helianthemum indoors.

Last Frost Date

The average date of last frost is April 15 in Glenwood. In the coldest months of winter you can expect an average low temperature of -20°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Glenwood and it can change quite a bit from year to year. Half of the time in Glenwood last frost occurs after April 15 so just be sure to be ready to protect your helianthemum in the event of a surprise late frost.

USDA Zone Info for Glenwood

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Glenwood

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