When to Plant Oenothera in Johnston, IA

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant oenothera in Johnston should be figured out by reviewing the USDA zone info.

Create beautiful hand-made plants at forever-plants.com

Planting Calendar for Oenothera

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

Oenothera do well in mild cold which means that you can plant them just a bit earlier in the year than more sensitive plants.

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

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Johnston. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Johnston is just an average the actual date of last frost changes from year to year. Since half of the time in Johnston there is a last frost after April 15 be ready to protect your oenothera if you have a late frost.

USDA Zone Info for Johnston

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 Johnston

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