Gardening in Illinois

Everything we have worked out for Illinois: what to plant and when, which varieties finish in time, the pests that actually turn up here, and the jobs that pay off month by month. We also cover the rest of the property, from lawns and soil to home care and energy, because a garden rarely stops at the vegetable bed.

The numbers first, because everything else follows from them. Measured at the weather station in Chicago, the last spring freeze runs April 11 to April 22 and the first fall freeze runs October 24 to November 3, USDA zones 5a-7b, 3,274 growing degree days in the year.

Garlic does well: 26.1 weeks below 40 °F, comfortably past the six it needs to form a proper head.

Elsewhere on the property in Illinois: the pests that turn up here.

Figures from NOAA's 1991-2020 climate normals. A state is not one climate: elevation, a large lake or the coast can move these dates by two weeks either way, so check your own county with the extension service before you spend money.

Potato Varieties That Suit Illinois

Potato Varieties That Suit Illinois

Illinois gardeners get the best results from early and mid-season potatoes suited to baking or boiling, planted as soon as soil hits 50 degrees rather…

What to Plant in Illinois in September

What to Plant in Illinois in September

September is the second planting season for Illinois gardeners. Soil is still warm from summer, but the first fall frost (October 24 to November 3, per…

What to Plant in Illinois in October

What to Plant in Illinois in October

October in Illinois splits into two very different halves. Early in the month, soil is still warm enough to plant garlic, shallots, and spring-flowering…

What to Plant in Illinois in May

What to Plant in Illinois in May

May is the month Illinois gardens open up. With the average last spring frost falling between April 11 and April 22 across the region, most of the state…