When to Plant Erysimum in Knoxville, IA

One of the first steps you take when you are determining 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.

It's a good idea to figure out when it's a good idea to plant erysimum by checking out the USDA zone info for Knoxville.


Planting Calendar for Erysimum

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

Since erysimum are one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than more sensitive plants.

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

The earliest that you can plant erysimum in Knoxville 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 erysimum and expect a good harvest is probably September. If you wait any later than that and your erysimum may not have a chance to really do well. If you are starting your erysimum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Knoxville may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Knoxville there is a last frost after April 15 so always be ready to cover your erysimum in the event of one of those late frosts.

USDA Zone Info for Knoxville

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Knoxville

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