When to Plant Nasturtium in Harrisburg, IL

One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Harrisburg you can figure out when it's the best time to plant nasturtium by looking at the USDA zone info.


Planting Calendar for Nasturtium

Frost tolerance for nasturtium: Not tolerant of frost.
When to plant: After the last frost has passed.

Nasturtium are not cold tolerant which means that you must wait until it warms up after the last frost has passed before you can plant them.

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

The earliest that you can plant nasturtium in Harrisburg is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant nasturtium and expect a good harvest is probably August. Any later than that and your nasturtium may not have a chance to really do well. You can get started a couple of weeks earlier by starting your nasturtium indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Harrisburg. In the coldest months of winter you can expect an average low temperature of -5°F.

Just be sure to remember that USDA zone info for Harrisburg may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Harrisburg there is a last frost after April 15 so make sure that you are prepared to protect your nasturtium in the event of one of those late frosts.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-5°F
Highest Expected Low0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Harrisburg

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