Illinois · Great Lakes & St. Lawrence Lowlands · hardiness zone 6a
Now
19°C · Overcast
Today
21° / 11°
Soil 6 cm
19°C
First frost
~48 days (Nov 1)
The kindest day for transplanting there is, and the safest for sowing.
In the garden now · September
The insects and soil life out near Chicago, Illinois in September. Most of them are on your side — learn the few that aren't before you reach for anything.

Danaus plexippus
Orange with heavy black veins and a white-spotted black border. The caterpillar is banded yellow, white and black.
What it does in the garden →Photo: Christine Young · CC BY 4.0

Archilochus colubris
Tiny, iridescent green above; the male has a black-looking throat that flares ruby in the right light.
Writing your field guide — reading the forecast, the moon and the map…
Overhead · Chicago, Illinois
The two clocks nothing on the ground can argue with: the length of the day, and the phase of the moon.
The sun
12h 30m of light
Sunrise
06:30
Solar noon
12:45
Sunset
19:00
A month from now the day will be 1h 23m shorter. Enough light for steady growth.
Right now · Chicago, Illinois
Nothing here is a guess. Each of these is read from this week's forecast and this location's climate record, and each one is pushing the season one way or the other.
192 frost-free days
Typically Apr 23 to Nov 1 here. Coldest night in the next week: 11.1 °C.
The hard edge of the growing season. Ice inside a leaf ruptures its cells — one night ends a tomato and sweetens a parsnip.
19.2 °C
Warm enough for beans, corn, squash, cucumber and transplanted tomato and pepper. Roots run hard at this temperature.
Seeds read soil temperature, not the calendar. Six centimetres down is where the decision gets made.
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Apis mellifera
Golden-brown, banded, furry thorax, and pollen packed onto the hind legs in visible baskets.
What it does in the garden →
Bombus spp.
Big, round and very furry, in black with yellow, orange or white bands.
What it does in the garden →
Syrphidae
Wasp-striped but a true fly: two wings not four, huge eyes, and it hovers dead still in mid-air.
What it does in the garden →
Papilio spp.
Large, with tails on the hindwings; black-and-yellow tiger stripes, or black with blue and orange spots.
What it does in the garden →Photographs are research-grade observations from iNaturalist, each credited to its photographer. Ranges and timing are typical, not guaranteed — 54 species are covered across Canada and the US.
The moon
Waxing Crescent
11% lit · waxing · day 3 of 29.5
Planting by the moon: New to first quarter: sow leafy crops and anything harvested for its leaves — lettuce, spinach, brassicas, herbs.
Fishing: good — feeding peaks in the days either side of new and full, and around moonrise and moonset.
Turn of the season
Fall equinox
Sep 22 · 7 days away
About 48 days to the average first frost (Nov 1).
Next moons
12h 30m
Losing about 3 minutes of daylight a day.
The one thing weather can't change. Plants count photoperiod to decide when to bolt, bulb, flower and go dormant.
73 GDD / 7 days
Steady heat. Tomatoes set fruit, corn stretches, and pest generations turn over on schedule.
Growing degree days: the running total of warmth above 10 °C. Crops and insects both run on this clock rather than on dates.
75.0 mm / 7 days
75.0 mm in a week is a lot. Expect blight pressure on tomatoes and potatoes, slugs at night, and blown-out, muddy rivers.
Sets the pace for everything: germination, fungal fruiting, slug nights, and how a river runs for the next three days.
4 of 7 flying days
4 good flying days ahead. Open flowers will get worked — leave a shallow water dish out and hold off on any spray until dusk.
A third of what you eat needs an insect to have visited first. Bees fly on temperature and wind, not on your schedule.