When to Plant Pearl onions in Knoxville, IA

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

You can figure out when it's the best time to plant pearl onions in Knoxville by referring to the USDA zone info.


Planting Calendar for Pearl onions

Frost tolerance for pearl onions: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Pearl onions tend to make it in mild cold which tells us that you can plant them just a tiny bit earlier in the year than more sensitive plants.

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

The earliest that you can plant pearl onions in Knoxville 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 pearl onions and expect a good harvest is probably August. You probably don't want to wait any later than that or else your pearl onions may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your pearl onions indoors.

Last Frost Date

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

Remember that USDA zone info for Knoxville is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Knoxville you get a frost after April 15 be ready to protect your pearl onions in the event of a surprise late frost.

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.