Buying smart

A cactus listing gives you a photograph and a price. Neither tells you the two things that decide whether the plant does well: how thick it is, and whether the cut end has healed properly. Here is how to read the rest of the page, and what to do in the ten minutes after the box arrives.

Six pieces of vocabulary do most of the work in a listing. Get these and you can read almost any of them.

The market's unit is inches, and almost every listing leads with a length. That is the one measurement sellers reliably publish, so read it before anything else — a photograph on its own tells you nothing at all about scale — what Scale means. Where a listing quotes a range rather than a figure, assume the short end, and where it quotes nothing, ask.

The number that actually predicts how the plant will do is thickness, and hardly any listing prints it. A fatter piece carries more stored energy, so girth is what decides whether a tip cutting — what Cutting means goes thin while it roots. It is the ratio that matters rather than raw length: a two-inch-wide tip wants around two to three feet of stem behind it. Short top cuts are common because they pack and post easily, and short top cuts are the ones that go thin.

A mid cut — what Mid cut means sidesteps the question entirely, because there is no tip to go thin. And if flowers are what you are after, look for old flower scars: a branch that has bloomed before is very likely to bloom again once it is cut and repotted.

Cut to order — what Cut to order means stacks three delays: the drying window, how often the seller takes cuts, and how often they ship. The useful flip side is that you can normally change or cancel right up until the knife goes into the mother plant — what Mother plant means.

In cold months, add a heat pack — what Heat pack means. There is a documented case of cuttings damaged in transit when the weather fell from 40–50°F to 5°F while they were in the post. Freshly callused cuts and recently rooted plants take cold far less well than an established column, and cold plus wet is much worse than cold alone. Most sellers disclaim transit temperature explicitly and ask you to think about your own local weather before you order.

On our side of that exchange, the packing is the part a buyer never gets to inspect before it matters. Cuttings must not touch each other in the box — spines wreck their neighbours — so they get a divider or a cardboard wrap each.

The touch test settles most of it: soft flesh means rot — what Rot means, and a hard dark patch does not. Black spots are fresh damage and white spots are healed scars, so white is the outcome you want. Spine-poke scars, where one cactus has jabbed another, come in a line or a cluster, and that pattern is the giveaway that the damage was mechanical.

Two things are worth refusing outright, whatever else the listing says. Dense clustered growth where pups are pushing out of pups out of pups may be witch's broom — what Witch's broom means, which is contagious and cannot be cured. White cotton-wool patches around the areoles — what Areole means or in the roots are mealybugs — what Mealybug means, and mealybugs are one of the things that carry it between plants.