Day 8 against day 14: what you are actually trading by waiting

Your tray is ready and you are wondering whether another few days would be worth it. That is the question here. If you are still working out whether it is ready at all, that is the other page.

The honest headline is that the biggest published gain shrinks to almost nothing once you divide it by time.

The first row and the last row are the same experiment. The 80.1 percent and the 7 to 12 day cycle are both published by Kyriacou and colleagues in 2021; the bottom row is arithmetic on those two numbers, and it is a calculation you can check rather than a figure anybody measured. Multiply the yield by the days: 1.801 times 7, divided by 12, is 1.051.

So, an eighty percent gain is a five percent gain, if your constraint is shelf space and time rather than seed. The authors say the same thing in their own words, that the trade has to be worked out genotype by genotype.

What to actually do

• Find your own plateau and stop there. In the one study that tested consecutive days, the gain ended on a specific day while the quality losses continued. One day past the plateau costs you something and buys nothing.
• Do the tray-day arithmetic before waiting for weight. Multiply the extra yield by the old cycle, divide by the new one. An 80 percent gain over five extra days was worth 5 percent.
• If seed is your constraint rather than space, wait. The arithmetic below assumes a shelf you want to turn over. A hobby grower with one tray and no schedule is buying the yield gain with time that costs nothing.
• If you sell on color, cut earlier than the weight says. Radish anthocyanins were 23 percent lower on day 11 than on day 9 while the tray was heavier.
• Do not choose a harvest day for nutrition. Some compounds rise, some fall, and the studies report concentration rather than the total per tray.
• Distrust any bitterness or texture claim tied to a day, including the ones on the pages selling you seed. Taste your own tray on two different days and decide for yourself.
• Write down what your own crop did. Fifty-seven of the 62 crops here say to test your own tray for the harvest window, so for most of what you grow your own notes are the record to build.

Where waiting genuinely pays, and where it stops

One controlled study cut the same crops on four consecutive days and measured what came out. USDA-ARS-linked work by Ortiz and colleagues grew Di Cicco broccoli and Rambo radish hydroponically, cutting broccoli on days 11 to 14 and radish on days 8 to 11.

Read the third row, because it is the one that decides the question. Waiting paid until a specific day and then stopped paying, while the quality measures kept falling. That is a plateau, not a slope, and it means the cost of waiting one day too long is real while the benefit is zero.

The radish anthocyanin series is the clearest trade in the literature. Across days 8, 9, 10 and 11 it ran 5,562, 5,748, 5,322 and 4,300 mg per kilogram. Yield was highest at the end of that run and pigment was lowest. If you sell radish on its color, the day that maximizes weight is not the day that maximizes what people are buying.

Nutrient concentration does not peak, and the tray total is a separate number

The claim that nutrients are most concentrated at first true leaf is repeated everywhere and the controlled record does not support it as a general rule. Different compounds move in different directions in the same experiment.

• Up. Total phenolics rose from cotyledon to one and a half true leaves by 57.8 percent in dill and 29.6 percent in chia. Broccoli chlorophyll rose through day 14.
• Down. Radish anthocyanins fell at day 11. Radish antioxidant activity fell after day 10.
• Barely at all. Total glucosinolates and phenolics were comparatively similar across broccoli days 11 to 14 and radish days 8 to 11.

And here is the gap that undoes most of what gets written about this. Every one of those studies reports chemistry as a CONCENTRATION, per gram of tissue. Not one reports the total per tray. A tray that is 20 percent heavier at a slightly lower concentration may contain more of a compound, less, or the same, and the arithmetic that would settle it needs matched yield and concentration in compatible units. The studies report concentration only, so weigh your own tray if the total matters to you.

So, a page telling you that waiting makes your crop more nutritious, or less, is going beyond what these studies report. Concentration is not yield.

The published windows are one to four days long

This directory has a field for how long a crop stays at the right stage, and it is the emptiest field on the site.

Five of the 62 crops here have a number. Fifty-seven say to test your own tray. Where a number exists it is short:

Set that against what the field publishes, which is "7 to 14 days". Those are two different quantities and they get used interchangeably. Seven to fourteen days is the range of dates on which a crop MIGHT be ready. The window is how long it STAYS ready once it is, and where anyone has measured it, the answer is one to four days.

Across the 61 crops here with a researched day range, the median range is 7 days wide. So the honest picture is a week of possible ready dates with a window of a day or two somewhere inside it, and for 57 crops you find where by testing your own tray.

Two of five pages examined give a numeric range at all, and zero of five publish a crop-specific validated window with measured endpoints.

What to check as the extra days pass

Bitterness. Two grower and supplier pages say crops past true leaf turn bitter, and one names radish and mustard as especially unforgiving. Both are practice. The panel work that exists compares different species on one day, so taste your own crop on two different days and write down which you prefer.

Texture. The stems getting stringy is the most repeated claim on this subject. Pinch and chew a stem each day and note the day it turns stringy.

Mold in a standing tray. The 2024 work measured decay after cutting, which is a different thing from mold in a tray still growing. Extension guidance on airflow and venting is sound, and it is not evidence that an older tray molds more, so keep venting and note the age of any tray that molds.

Collapse. The word is borrowed from cereal agronomy and it does not transfer to a dense tray. Note the day your own canopy starts to bend or flatten.

All four of those are things you will read as facts. They may all be true, so check each one on your own trays.

What to track on your own trays

• Weigh the cut tray for each harvest day. The studies report concentration, so cut weight by day is the number that tells you the tray total for your crop.
• Write down your harvest window. For the 57 crops here that say to test your own tray, note the first day the crop is ready and the last day it is still good.
• Taste by harvest day. Write down which day tastes best, in your own words.
• Note texture by harvest day. Record the day stems start to feel tough or stringy.
• Note the age of any tray that molds. It shows whether a standing tray held longer molds more in your room.
• Weigh your cuts from day 8 to day 14. The dry matter comparison here is between crops, from 38.55 g/kg fresh weight for broccoli to 94.34 for sunflower, rather than between days, so your own day-by-day weights fill that in.
• Price your own bench space. Write down bench space, lamp hours, water, labor and rejects against harvest date, which is the calculation every commercial grower is actually making.

Sources

Opened 2026-08-12. The harvest window count, the day range spread and the tray-day arithmetic are this site's own, computed for this page on 2026-08-12 across the 62 crop entries here.

• Ortiz and colleagues, harvest stage in broccoli and radish microgreens, 2024 (PDF) - hydroponic Di Cicco broccoli cut days 11 to 14 and Rambo radish days 8 to 11, the 20 percent yield gain to day 13 and day 10, the absence of a significant further gain the following day, broccoli chlorophyll rising from 0.62 to 0.75 mg per gram fresh weight, radish antioxidant activity peaking at day 10, the radish anthocyanin series of 5,562, 5,748, 5,322 and 4,300 mg per kilogram across days 8 to 11, and the least visual decay at the best-tested day over 16 days of storage at 4°C.
• Kyriacou and colleagues, first against second true leaf in four brassica microgreens, 2021 - the 80.1 percent mizuna fresh yield increase, the crop cycle lengthening from 7 to 12 days, the 41.7 percent reduction in turnover, the finding that the cost and benefit must be worked genotype by genotype, and the largely genotype-dependent mineral and carotenoid results. The publisher page returned HTTP 429 and the PubMed record returned a CAPTCHA on direct open.
• Barut Gök and colleagues, cotyledon against 1.5 true leaves, 2024 and the article PDF - total phenolics rising 57.8 percent in dill and 29.6 percent in chia between the two stages, across dill, chia, garden cress, radish and red beet.
• Di Gioia and colleagues, 17 microgreen species, 2023 - dry matter at one commercial stage running from 38.55 g per kg fresh weight in broccoli to 94.34 in sunflower, average 56.90. A comparison between species rather than between harvest days, and used here only to show that the day comparison does not exist.
• Microgreens production review, 2024 - the sensory panel comparing six species at one stage, with flavor the strongest predictor of overall eating quality, which is the evidence that exists in place of a by-day panel.
• Microgreens review, 2025 - the broad 7 to 21 days after germination category reported in the wider literature in place of a validated window.
• USDA Agricultural Research, microgreens, 2014 - the description of microgreens as typically cut 7 to 14 days after germination with developed cotyledons before expanded true leaves, and the cotyledon and true leaf terminology used throughout this page.
• University of Maryland Extension, growing microgreens and baby greens indoors - airflow and venting guidance, used here as sound extension advice and explicitly not as evidence about tray age and mold.
• University of Nevada Extension - seed, water, temperature, humidity and handling as the food safety factors, used for the same distinction.
• Grower and supplier pages, used as practice only and as the source of the five-page audit: True Leaf Market's starter guide, which says crops grown beyond true leaves may develop a bitter flavor, and Wind River Greens on when to harvest, which claims later stems turn fibrous and bitter and names radish and mustard as especially unforgiving.