M4BB3 (Malo 4 x Betty Boom)

Unpack right away. Take the plant out of the box the day it arrives and brush off packing material. A plant that arrives cool, wrinkled or light is fine — it is just thirsty. Soft is a different thing: soft flesh means rot, and that is what the 48-hour guarantee is for.

Check the callus — the cut base. The cut face should already be hard, dry and shiny, like a fingernail rather than like flesh, and then it can be potted the same day. If it is not, stand the piece upright somewhere shaded with good airflow until it is. An ordinary cutting takes one to two weeks, longer when the air is very humid; a slim pup is quicker and a really fat column slower. The face is what tells you it is done, and you will never be early. Do not put a fresh wet cut into soil. Once the face is hard, set the stock one to two inches deep, just enough to stand it up. A rooted plant has no cut face and skips this step.

Pot it up. Use a fast-draining mix — roughly two parts gritty mineral to one part cactus soil. Pumice is the best of the mineral part and perlite works. Pot into dry or barely damp mix, never wet, and no deeper than it needs. If it wobbles, stake it: burying more of a plant is not safer, it is the commonest way to lose one.

Watering a graft with no roots yet. Nothing on planting day. About a week later, a splash — just enough to darken the top inch of the mix, and no further down than that. A second small sip a week after that. The first proper soak only once you can see roots. There is no full soak before roots appear, and watering a graft with no roots because it looks thirsty is the commonest way to lose one: it has no roots to drink with yet. Roots usually take about two months, and longer in winter, which is fine. Around week six it looks its worst, and that is normally the point just before roots. When a gentle wiggle near the top meets resistance and the ribs fill out again, it has rooted; never pull it up to check.

Grafts. The plant you paid for is the one on top; the rootstock under it is a different plant. Any pup that comes up on the rootstock below the join has to come off, or it starves the plant on top.

Light. Bright light, but ease into full sun. It has just spent a few days in a dark box, so give it shade with plenty of ambient light for a few days, then half sun, then full. Going from shade to hard sun in the space of a week is enough to scar a plant permanently.