Does Weed Expire?

Not in California, unless the grower chose to print one. The state's labeling rule for flower lists what a package has to show, and the line that matters here is "The date of packaging for retail sale." Nothing in that rule asks for an expiration date.

If a best-by date is on the jar, the shop is bound by it. A retailer can't put cannabis on sale until it "has verified that the cannabis goods have not exceeded their best-by, sell-by, or expiration date if one is provided."

So the date you'll find tells you when the flower went into the jar. Counting forward from it is up to you.

The state starts one clock, and it starts at the lab. Every batch is tested before it can be sold, and the rule for distributors reads: "Cannabis goods that have not been transported to retail within 12 months of the date on the certificate of analysis must be destroyed or retested by the licensed distributor in possession of the cannabis goods." That's a year to reach a store. It isn't a limit on how long a jar can sit once it's there.

We can't quote you a rule for the shelf, but we can count. On September 18 our Hayward and Tracy menus listed 241 flower products. 25 days later, 108 of them were off the menu and 94 new ones had come in. That's 45% of that day's flower shelf gone in under a month.

A listing leaves the menu when it sells out or gets pulled, so that number counts jars moving. It doesn't tell you the age of any one jar. The packaging date does.

The oldest careful answer is from 1976. Researchers stored herbal cannabis and resin for up to two years and concluded that "carefully prepared herbal or resin cannabis or extracts are reasonably stable for 1 to 2 years if stored in the dark at room temperature."

A later study from the University of Mississippi measured the slow part. Flower kept in closed barrels, in the dark, at room temperature lost THC year after year. Its concentration "decreased by 16.6% ±7.4 of its original value after one year" and by 26.8%, 34.5% and 41.4% after two, three and four.

A 2019 study in Forensic Science International found a much steeper drop. It kept samples for four years, and in the ones left at room temperature, lit or dark, "almost 100% of THC was degraded" by the end. The two studies don't agree on the speed. They agree on the direction: THC goes down, and CBN, which THC breaks down into, goes up.

A grinder breaks those containers open, which is its job, and pre-ground flower has already been through one. We list 6 pre-ground flower products across the two menus, from Sunsmoke, each 14 g at $2.14 a gram. Buy it for this week, not for the back of a drawer.

Mold needs water, and California checks for that before flower is sold. A lab measures the flower's water activity, and the sample passes "if the water activity does not exceed 0.65 Aw." The same test covers pre-rolls.

That test happens once, before the jar reaches us. After you open it, the jar is only as dry as the place you keep it, and a steamy bathroom or a hot car is the wrong place.

If flower smells musty, or you can see fuzz on it, don't smoke it. If a jar from us was like that when you opened it, call or text the help desk. Our return terms are in the FAQ.

The smallest jar of flower we sell is an eighth. Eighths are the size we stock most: 129 of them, against 91 half ounces and 7 ounces on the two menus. A bigger jar costs less per gram, and we measured how much less. It's also the jar you'll be opening for longest.

If a half ounce lasts you a month, buy the half. If it lasts you a season, buy eighths and come back.

Flower from our own Eden, The Classics, Honest Flower, Honeycomb Farms and High Road labels sits beside the other growers we carry on the flower page. Get the order in by 7pm and it goes out for delivery the same day, or collect it from the Hayward or Tracy shop.