The Cannabis Harvest Date, Explained
Read the harvest date, because it is the only date on a cannabis label that tells you how long the flower has been aging. For flower you plan to smoke, we look for a harvest within the last six months and treat anything past a year as a discount jar, whatever the price. The packaged-on date can trail the harvest by months, so when the harvest date is missing, ask for it before you pay.
By Eleanore Editorial, editors of the eleanore guides to cannabis craft · Published
You are holding the jar. You have turned it over twice, looking for a number that means something, and found a sticker that reads Packaged 09/18 next to a batch code and a THC figure in large type. The budtender, who is lovely, tells you it is fresh. It came in Tuesday.
Tuesday is when the truck came.
It says nothing about when the plant was cut, which is the date that actually decides what is in that jar, and which a surprising number of producers leave off the label entirely. We have bought enough flower on the strength of a recent packaging date, and opened it at home to the smell of a hay barn, to hold a firm view on this. The harvest date is the single most useful line a producer can print. When it is missing, the missing part is usually the point.
The dates on a cannabis label
A typical jar carries one or two dates, and the certificate of analysis behind it carries another. They record very different events. Here is what each one tells you, and what it can quietly leave out.
| Date on the label | What it records | What it can hide | How far to trust it |
|---|---|---|---|
| Harvest date | The day the plant was cut | Nothing about age. It can hide a rushed cure, which the packaged date will reveal. | High. This is the one to read. |
| Packaged on | The day the flower went into this jar | Weeks or months the flower may have spent in a bulk tote before that | Medium. Tells you the latest the flower could be, never the earliest. |
| Lab test date (on the COA) | The day a lab sampled the batch | Everything after the sample, including a long stay in a warm stockroom | Medium. Useful as a floor when no harvest date is printed. |
| Best by or expiration | A date the producer chose | How it was chosen, which is rarely explained | Low for flower. More meaningful on edibles and drinks. |
| “It just came in” | The day the delivery reached the shop | The whole life of the flower before the truck | None at all. |
The gap between the first two rows is where most of the mischief lives. Flower is often cured and then held in large sealed totes until a buyer places an order, and only then weighed into eighths. A jar packaged in September can hold flower harvested the previous October, and nothing on a packaged-only label will tell you so. The same gap, read the other way, also tells you how long the cure could have lasted; our guide to how to tell if cannabis is properly cured does that arithmetic.
What the months do to a jar
Aroma leaves first. The terpenes behind bright notes like lemon peel and fresh pine are the lightest and most volatile compounds in the flower, and they start to slip away from the moment the plant is cut, faster in a warm room and faster still in moving air. The heavier notes (earth, black pepper, old wood, the leathery base of a good Afghani) hang on for much longer, so an aging jar fades from the top down and ends up smelling darker and heavier than it did in spring.
THC is slower to change. Over many months oxygen converts some of it to CBN, which people tend to describe as heavier and sleepier, and that is why a forgotten jar so often smokes flat and drowsy rather than simply weak. Our page on what CBN is goes further into that conversion. How fast any of this happens depends almost entirely on storage, so read the bands below as what we usually find on a shop shelf. A cool, dark cupboard at home runs slower.
| Time since harvest | In the jar | In the smoke | Our verdict |
|---|---|---|---|
| Under 3 weeks | Loud, sometimes grassy or sharp | Can be harsh and green | Probably under-cured. Fresh is not yet finished. |
| 1 to 4 months | Full top notes over a settled base | Smooth if the cure was patient | The window we shop for |
| 4 to 6 months | Citrus and pine notes softening first | Still good in a sealed, cool jar | Buy it, but smell it first |
| 6 to 12 months | Earth and spice outlast the fruit | Flatter, rounder, a little sleepier | Fair at a lower price; poor at a top-shelf one |
| Over 12 months | Hay, or very little | Dull and drowsy as THC slowly becomes CBN | A discount jar, whatever the sticker says |
The first row surprises people. A harvest date two weeks old looks like the best news on the shelf, and it usually means the flower spent about ten days hanging and four in a jar before someone sealed it for sale. That is a dried plant. Cured is something else, and it takes time nobody can buy back later.
The sun-grown calendar
Full-term outdoor cannabis has one harvest a year, and in Mendocino and Humboldt it comes down between late September and early November. Add two weeks hanging and a month or more of cure, and the first finished jars of a new harvest reach good shops around late November and December, as our guide to sun-grown cannabis describes. From then until about March, outdoor flower is as good as it will ever be.
Then the calendar turns against it. Every outdoor jar on a California shelf in July is at least seven months old, by simple arithmetic, and often older. That is the season when we buy light-dep greenhouse flower, which can be harvested from early summer, or carefully grown indoor, which a well-run facility harvests in every season. The guide to indoor vs outdoor cannabis covers the rest of that trade.
Buy outdoor in winter.
A note on the word fresh
Every jar is fresh on the day it arrives at the shop.
Where each date fits (and where it does not)
The harvest date matters most for whole flower and for pre-rolls, where the aroma you are paying for is the same aroma that time removes. It matters less for edibles and drinks, which are usually made from extracted oil rather than raw flower and age on a different schedule entirely; there the production or best-by date is the more honest guide. And it matters least of all for pressed hash, which, as our traditional hashish guide explains, is pressed resin that can taste better after a few months of rest than on the day it was made.
We should also concede the obvious limit of our own rule. A jar harvested seven months ago, sealed in glass and kept cool and dark the whole time, can easily smell better than a jar harvested two months ago that sat in a warm display case beside the window. The date gives you the starting odds. Your nose settles the bet, and our guide to storing cannabis flower explains how to keep the odds in your favor once the jar is home.
The rule applies to us as well. Our Parlor Smokes are sun-grown flower blended with botanicals (rose petal and chamomile in The Fainting Couch, citrus and mint in Afternoon Ruse) at about 2.5 percent THC, and you cannot see the flower inside a pre-roll any more than you can in anyone else’s. If you want the harvest window for a batch, write to hello@deareleanore.com and ask. You should be able to ask any producer that question and get a straight answer.
At the counter
Ask for the harvest date first, before the price and before the THC figure. If the label lacks it, ask whether the shop has the certificate of analysis, and look for the date the lab sampled the batch; the flower is at least that old. Then open the jar and smell it, and give it a few seconds, because the bright notes in a young jar arrive immediately while an old jar takes a moment to say anything. Our guide to reading a COA shows where the dates sit on the page.
A shop that cannot find any date older than “Tuesday” has given you an answer of a kind. It is a fine reason to buy the jar at a lower price, and a poor reason to pay for the top shelf, which, as we argue in what top shelf cannabis means, should be about freshness and care long before it is about a famous name.
Frequently asked questions
How old is too old for cannabis flower?
For flower you plan to smoke for pleasure, we aim for a harvest date within the last six months and treat anything over a year old as a discount jar. Storage changes the answer: a sealed glass jar kept dark and near 60°F ages far more slowly than flower left in a warm stockroom or a sunny window.
What is the difference between a harvest date and a packaged date?
The harvest date is when the plant was cut. The packaged date is when the flower went into the container you are holding, which can be weeks or many months later if the flower sat in bulk storage first. Only the harvest date tells you how long the flower has been aging.
Does old cannabis lose potency?
Slowly. Aroma goes first, because terpenes are volatile and evaporate within months in warm, open conditions. THC degrades more slowly, and with oxygen and time some of it converts to CBN, which is why old flower often feels flatter and drowsier rather than simply weaker.
When is the best time to buy outdoor cannabis?
In Northern California, full-term outdoor plants come down from late September into November, then spend weeks drying and curing, so the first finished jars of a new harvest reach shops around late November and December. Buying from then into early spring gets you outdoor flower near its best. By summer the same jars are seven months old or more.
What if the jar has no harvest date?
Ask the shop, and if they cannot tell you, look for the lab test date on the certificate of analysis. Testing happens after harvest, so the flower is at least as old as that date. A shop that cannot produce either should not be charging top-shelf prices.