Gardening in Washington
District of Columbia · Northeast Atlantic Coast & Piedmont · hardiness zone 8a
Fall · September 14, 2026
Washington, District of Columbia
Now
22°C · Clear
Today
28° / 19°
Soil 6 cm
25°C
First frost
~55 days (Nov 8)
Peak photosynthesis and peak water loss. Beds dry fast and transplants sulk.
- Ruby-throated hummingbirdbest now — Feeding hardest in the first and last hour — it burns through the night's reserves by dawn and must refuel before dark.
- Green lacewingbest now — Adults fly at dusk and through the night; the larvae hunt around the clock and do the real work.
In the garden now · September
Who else is working the garden
The insects and soil life out near Washington, District of Columbia in September. Most of them are on your side — learn the few that aren't before you reach for anything.
PollinatorMay–OctMonarch butterfly
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
Writing your field guide — reading the forecast, the moon and the map…
Overhead · Washington, District of Columbia
The sky over the garden
The two clocks nothing on the ground can argue with: the length of the day, and the phase of the moon.
The sun
12h 27m of light
Sunrise
06:49
Solar noon
13:03
Sunset
19:17
A month from now the day will be 1h 15m shorter. Enough light for steady growth.
Right now · Washington, District of Columbia
Forces at work
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.
- Quiet right now
Frost
211 frost-free days
Typically Apr 11 to Nov 8 here. Coldest night in the next week: 13.6 °C.
The hard edge of the growing season. Ice inside a leaf ruptures its cells — one night ends a tomato and sweetens a parsnip.
- Working for you
Soil warmth
25.5 °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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