When to Harvest
Days to maturity gets you into the right fortnight. The ripeness signs get you the right day. Pick a crop for both, and add the date you planted for an expected harvest range.
Choose your crop
Leave blank to see the maturity figures and ripeness signs only.
This matters. Seed packets count days to maturity from different starting points depending on the crop.
Only used to check your expected harvest against your average first fall frost.
How this is calculated, and why the signs matter more
The arithmetic is trivial. Planting date plus days to maturity gives a first harvest date, and the harvest window length gives the far end of the range. This tool shows a range rather than one date because published days-to-maturity figures differ between seed companies for the same crop by 10 to 20 days, and the figure on the packet describes ideal weather.
The arithmetic is also unreliable, and any tool that hands you a single confident date is hiding that. Days to maturity is a variety average measured under trial conditions. A cool June, a dry August, poor soil, crowding or a heat wave during flowering all move it, usually later. In practice a two week error either way is completely normal.
So the ripeness signs are the real answer. The tendril nearest a watermelon browning off, the lower leaves of garlic going brown while five or six stay green, onion tops flopping at the neck on more than half the row, a pumpkin rind that resists a thumbnail: those are the tests experienced growers actually use, and they work regardless of what the packet claimed. Every crop here carries its signs.
Two adjustments are applied and shown separately. If your crop's days to maturity is counted from transplant and you tell us you sowed seed instead, the raising time in the tray is added. If maturity lands after September 1, an autumn slowdown allowance of 10 to 14 days is added, because shortening day length slows growth measurably. Both are optional and both appear on their own line in the working.
Frost checks use average frost dates from the same regional table as our frost date lookup, so the two pages cannot disagree.
Days to maturity and the key sign, for every crop
The whole table on one screen. This is the same data the tool above runs on, so the two can never disagree.
| Crop | Days to maturity | Counted from | Picking lasts | The one sign to check |
|---|
Keep planning
Harvest dates are the last link in a chain. Here is the rest of it.
Common questions
My crop passed its days to maturity and nothing looks ready. Did I do something wrong?
Almost certainly not. Days to maturity is a variety average from trial conditions, and it assumes weather you did not necessarily get. A cool spell, a dry patch, crowded plants or thin soil each add days. Running two weeks late is ordinary. Go by the signs for your crop rather than the calendar, and only start worrying when the plant itself looks wrong rather than merely slow.
Does days to maturity count from sowing or from transplanting?
It depends on the crop, which is exactly why so many people are caught out. For crops normally started indoors, tomatoes, peppers, eggplant, broccoli, cabbage and cauliflower among them, the packet figure counts from the day the transplant went into the garden, and the six to eight weeks in the tray are not included. For direct sown crops such as beans, carrots, radish and corn it counts from sowing. This tool states which applies and adds the raising time for you when you say you sowed seed.
How do I actually tell a watermelon is ripe?
Three signs together, never one alone. The curly tendril nearest the fruit stem dries and turns brown. The ground spot where the melon rests on the soil turns from white to a creamy or buttery yellow. And the melon sounds dull and hollow rather than sharp when you knock it. Watermelon does not ripen after picking, so a mistake here is permanent, which is why you wait for at least two of the three.
When do I pull garlic and onions?
Garlic: when the lower three or four leaves have gone brown but five or six above them are still green. Every green leaf is one intact wrapper around the bulb, and a bulb pulled with no green left has no wrappers and will not store. Onions: when the tops flop over at the neck on more than half the row of their own accord. Do not bend them over yourself, which was old advice and mostly shortens storage life.
Can I harvest before the plant is fully mature?
Frequently, and it is often better. Zucchini at 6 inches beats zucchini at 14. Kohlrabi is tender at 2 inches and woody at 4. Beets are sweet at 2 inches and fibrous at 4. Radish goes pithy and hot within days of being ready. Baby carrots, baby beets and cut-and-come-again lettuce are all deliberate early harvests. The exceptions are the fruits that do not ripen after picking, which are the ones to be patient with.
Which crops keep ripening after picking and which do not?
Tomatoes, cantaloupe, and to a limited extent pears and avocados will continue to soften and develop after picking, so an almost-ripe tomato brought in ahead of frost still finishes well. Watermelon, cucumber, peppers, sweet corn, peas and every leafy green do not. What you pick is what you get, and with sweet corn the sugar starts converting to starch within hours, which is why homegrown corn tastes different at all.
Does frost ruin everything?
No, and treating it that way costs a lot of food. A light frost improves kale, collards, Brussels sprouts, parsnips, carrots and leeks, because the plant converts starch to sugar as a natural antifreeze. It ends tomatoes, peppers, eggplant, beans, squash, cucumbers, corn and basil immediately. This tool flags which side your crop is on when you give it a ZIP code.
Where do these figures come from?
Days to maturity are typical ranges across widely sold varieties, given as ranges precisely because seed companies disagree. Your own seed packet is a better number than any general table and should win. The ripeness signs are the standard indicators taught by US cooperative extension services and used by market growers. For anything you plan to store through winter, check your county extension office's storage and curing guidance too, since that varies more by region than the harvest signs do.