When to Plant Catnip in Illinois

Growing Catnip in Illinois: Complete Guide

Catnip (Nepeta cataria) is a warm-season crop that needs a head start indoors before Illinois's last frost. Most Illinois gardeners begin seeds indoors around Wednesday, February 18, 2026 and move transplants outside around Wednesday, April 29, 2026, after the risk of frost has passed.

Because Illinois stretches across 5 USDA hardiness zones (5a, 5b, 6a, 6b, 7a), planting windows can shift by as much as six to eight weeks from one end of the state to the other. Gardeners in the warmer southern zones can start earlier, while those in cooler northern zones should wait until the zone table above shows their last frost has passed.

With 90 days to maturity, Catnip needs the indoor head start that Illinois's growing season requires. Starting indoors ensures you have strong transplants ready the moment outdoor conditions are right.

Catnip requires full sun to partial shade and low (less than 1 inch/week) moisture. Most of Illinois receives adequate sunlight during the growing season, though gardeners in humid eastern regions should watch for fungal issues and ensure good air circulation.

For the most precise planting dates tailored to your exact location, enter your ZIP code on our planting calendar or use the zone table above to find the schedule for your area of Illinois.