When to Overseed a Lawn in Illinois
The safe window for overseeding a cool-season lawn in Illinois runs from late August through mid-September, and the exact cutoff depends on your county’s…
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.
What Eats Spinach in Illinois, and When
University of Illinois Extension tracks eight garden pests statewide, but only two realistically show up on spinach leaves: Japanese beetle and brown…
What Eats Onion in Illinois, and When
Search “onion pests” in Illinois and most results come back full of tomato hornworms, squash beetles, and tree-eating insects, nothing built for alliums.
What Eats Corn in Illinois, and When
University of Illinois Extension documents two pests from its state pest list that actually feed on corn: the Japanese beetle, which clips silks right as…
What Eats Pumpkin in Illinois, and When
Illinois gardeners dealing with chewed leaves, wilted vines, or scarred rinds on pumpkin plants are usually looking at one of three insects the state…
What Eats Potato in Illinois, and When
In Illinois, the short answer is one insect: the Colorado potato beetle. It’s the only pest on the University of Illinois Extension’s documented list for…
What Eats Parsnip in Illinois, and When
Of the eight pests University of Illinois Extension documents for the state, only two have a real shot at feeding on parsnip: Japanese beetle and brown…
What Eats Carrot in Illinois, and When
None of the eight pests University of Illinois Extension documents for this state are specialist carrot feeders.
What Eats Beet in Illinois, and When
Beets grown in Illinois face almost no dedicated insect threat. Of the species University of Illinois Extension documents for gardens across the state…
First and Last Frost Dates in Illinois
The short answer: in the reference Illinois location tracked by NOAA, the last spring frost typically falls between April 11 and April 22, and the first…