When to Plant Marigold in Monticello, IL

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Monticello you should be able to determine when it's a good idea to plant marigold.


Planting Calendar for Marigold

Frost tolerance for marigold: Not tolerant of frost.
When to plant: After all chance of frost has passed.

It's not a good idea to plant marigold until after all chance of frost has passed because they do not do well in cold weather.

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

The earliest that you can plant marigold in Monticello 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 marigold and expect a good harvest is probably August. If you wait any later than that and your marigold may not have a chance to grow to maturity. If you are starting your marigold indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Monticello the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Monticello is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Monticello you get surprised by a frost after April 15 be ready to protect your marigold in the event of a surprise late frost.

USDA Zone Info for Monticello

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 Monticello

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