Questions and answers

A group of tall, column-shaped cacti from the Andes mountains of South America. They are grown as ornamental garden and container plants. The name refers to the hairy flowers and fruit they produce. Unlike the desert cacti most people picture, they come from places with real rainfall and heavy dew — which is why they want more water than a typical cactus.

"San Pedro" is the common name usually given to one species in the group, Trichocereus — what Trichocereus means pachanoi — what Pachanoi means. The other names you will see — Peruvian Torch (peruvianus — what Peruvianus means), Bolivian Torch (bridgesii — what Bridgesii means), scop (scopulicola) — are close relatives with the same care needs. In practice growers use all these names loosely, and the formal botanical naming has been revised more than once and is still argued about.

Fast, for a cactus — but it depends enormously on your climate. In Southern California, roughly one to three feet a year. In Spain, measured single-season growth on three plants was 22, 20 and 17 inches. Move the same collection to northern Europe and it grows at less than half that pace. A cold-climate grower will see much slower growth but still real thickening over a decade.

A clone — what Clone means is one original plant plus every piece ever cut from it. These cacti cannot pollinate themselves, so seed from a named plant never comes out the same — the only way to copy a specific plant exactly is to cut a piece off it. That is why collectors trade named cuttings — what Cutting means rather than named seed, and why the names are usually a person, a street, a collection code or a nickname.

Probably not. Two things are happening. First, the same clone — what Clone means genuinely looks different in different conditions — full sun makes longer spines and yellower, blockier growth; shade makes slimmer, greener, bluer plants. Second, a clone name can drift: at least one well-known name is documented as covering several genetically distinct plants held by different collectors. So the same name is not a guarantee of the same plant.

No, and neither can anyone else honestly. Growing conditions and age change every feature people use to identify these plants, so photographs are pointers at best — real certainty needs flowers or DNA. We will happily tell you what we can see in your photo (rib — what Rib means count, spine type, skin — what Epidermis means colour), but we will not put a name on it. That is a rule we hold ourselves to on our own plants too: every name on this site is the label the plant came to us with.

Photograph it in the box before you do anything else — that is what every seller's claim window needs. Then take it out; a cutting — what Cutting means should never sit sealed in cardboard longer than it has to. Check the cut face is hard, dry and shiny. Put it somewhere shaded but bright for a few days, standing upright, and do not water it and do not plant it in wet soil.

No — that step already happened. A cutting — what Cutting means bought from a proper seller arrives already callused, which is the whole point of the two-to-three-week wait between cutting and shipping. The drying advice you read online is written for someone who just cut a piece off their own plant.

One to two inches — just enough to hold it up. Depth is the single biggest cause of a rotted — what Rot means cutting — what Cutting means, because the green flesh below the soil line is the vulnerable part. If it is tall and wants to fall over, stake it rather than burying it deeper.

Not at planting. Wait about a week, then give it a splash — just enough to darken the top inch of the mix. Another small sip a week after that. Only once you can see roots have taken hold does it get a proper soak. (The stricter schedule — nothing at all until roots show — works too; what fails is mixing the two.) Water sitting around an unrooted cutting — what Cutting means has nothing to drink it and everything to rot — what Rot means.

Usually a few weeks to about two months, but it genuinely varies — from days to several months. Once it starts, it moves fast. Warmth and long days speed it up; cold and dark slow it right down.

Don't dig it up — pulling a cutting — what Cutting means to check breaks the new roots and sets it back. Watch the plant instead. The ribs fattening is the real signal: it means water is being absorbed. A fresh growing tip is another. If you must check physically, the only permitted move is a very gentle side-to-side wiggle near the top — resistance means roots are gripping.

Almost certainly not — that is the normal sequence. A cutting — what Cutting means typically keeps growing a little, then visibly shrivels as it lives off stored water, and roots appear shortly after that. Once it starts drinking, the column plumps back up. It is safe to leave it dry right up until it wrinkles, then give it a little.

Probably not. Vertical growth commonly stalls for months while all the plant's energy goes into building a root system. That is invisible progress. If it is also getting no warmth or no light, or the mix is holding water rather than draining, those are the three things to fix.

On a tip cutting — what Cutting means it is obvious — the growing point goes up. On a mid cutting, look at the little notch just above each areole — what Areole means (the felted spot the spines come from). It looks like a seagull's wings, and the seagulls fly upward. Spines generally point down. A mid cut — what Mid cut means planted upside down never grows and eventually dies.

Bright, but not automatically maximum. The common belief that these want all the sun they can get is wrong for hot, high-UV places, where all-day sun turns them yellow. In milder or more northern climates, full sun is often fine. The important rule is not how much, but how fast: every increase in light has to be gradual. One week's jump from cloudy and 80°F to sunny and 95°F is enough to cause a burn.

Water thoroughly, let it dry out, then water thoroughly again. In real heat you can water before it is bone dry; in cooler weather let it sit dry for a few days first. A rough hobby rhythm is about once a week in the growing season, more in extreme heat. What you must not do is either extreme: leaving it bone dry for weeks, or leaving it soaking.

Look at the ribs. They work like an accordion — squeezed tight and sunken means the plant is running low; spread wide and flat means it is full. Cacti cannot droop like a leafy plant, so rib — what Rib means compression is the signal. Wrinkling of the skin — what Epidermis means after several hot days means the internal reserve is empty and it needs water now.

Something that drains fast. A reliable starting point is roughly two thirds gritty mineral material (pumice — what Pumice means, lava, perlite — what Perlite means) to one third organic — what Organic (in a soil mix) means material. Richer, more organic mixes grow plants faster where the drainage genuinely keeps up — the ratio is a lever, not a law — but drainage itself is not negotiable. And one thing to skip no matter what: do not put a layer of gravel in the bottom of the pot. It makes drainage worse, not better.

Anything with drainage holes and no attached saucer. A handy rule: the plant should not be taller than the pot is wide, or it will topple. Fill the soil to about half an inch below the rim — that gap is your watering reservoir. Avoid glazed decorative pots with no hole; if there is a plastic liner inside one, use the liner.

Not to keep it alive, but yes if you want it to grow well — these are heavy feeders by cactus standards, and they respond visibly. Feed during the warm growing season, at label rate, and make some of your waterings plain water to flush salts through. Stop feeding in extreme heat and hold off entirely through winter. One rule that saves plants: never put fertiliser near a freshly planted cutting — what Cutting means whose buried skin — what Epidermis means is still green.

Full-speed growth happens with daily highs between about 68 and 86°F. Above about 95°F growth slows and the plant wants shade. Growth stops and dormancy — what Dormancy means begins when highs stay below about 60°F, with roughly 55°F being the main trigger.

It depends on your winter and, crucially, on whether the soil is dry. Kept dry, most survive nights down to about 25°F provided the temperature climbs back above freezing at sunrise — but cold tolerance genuinely varies between varieties. A cold plant that is also wet is in real danger; a cold plant that is dry usually is not. If your winters are harder than that, overwinter it somewhere that stays between about 35 and 55°F, dry, and stop watering.

Yes, but light is the hard part. A sunny window is generally not enough for a mature plant — the number to aim for is at least 750 PPFD — what PPFD means on a proper LED panel, with 1000–1250 much better. The other trap is heat without light: a warm heated room in winter tells the plant it is growing season while the light says otherwise, and it produces thin, weak growth. Keep air moving.

Press it. Soft means rot — what Rot means; hard means not rot. A hard dark patch, a black blister you cannot dent, or a healed white scar are all fine and need nothing. Soft, squishy, dark tissue does need cutting — what Cutting means out with a sterilised knife, back until no discoloured flesh remains — and re-sterilise the blade between every cut, or you carry the infection into the next slice. Rot starting below the soil line is the dangerous kind; rot higher up much more often stops by itself.

Most often too much sun, especially if it is worst on the sunny side and on the raised parts of the ribs. But yellowing all the way round the lower column points at a nitrogen or calcium shortage instead, and cold weather colours the whole plant temporarily and reverses in spring. The tell is where the colour is and whether it is on one side.

That is etiolation — what Etiolation means. On a rooted plant it means not enough light. On an unrooted cutting — what Cutting means it means the tip is running ahead of what the plant can supply — nothing to do with light. Either way the thin section stays thin permanently; it can fatten again above the waist, but the narrow part is a permanent weak spot. Fix the cause first, then either live with the waist, or cut the tip off and re-root or graft — what Graft means it.

Run the quick tests before you spray anything. If it wipes off with a damp cloth or toothbrush, it is scale — what Scale means; if it will not budge, it is old scarring. Sticky white cotton-wool patches are mealybugs — what Mealybug means. If the insect jumps when you blow on it, it is a springtail — what Springtail means and it is harmless. Fast-moving specks that make no webbing are predator mites and are on your side. Identify first: broad-spectrum spraying kills the predators and lets the real pest bounce back from protected eggs.

Maybe, and maybe not — this is the one confusion worth taking seriously. Natural monstrose — what Monstrose means and crested — what Crested (cristate) means growth is prized. But witch's broom — what Witch's broom means looks similar and is a contagious, incurable infection spread by sap-sucking insects. The tell is a pup — what Pup means on a pup on a pup — each new pup already pushing more from its own areoles — along with ribs vanishing and a lot of woolly fluff. Pest damage to the growing tip can raise a similar, harmless cluster that clears up once the pest is treated, which is why the move is to isolate first and identify second. Isolation costs you nothing; a spread costs the collection.

Usually too much water at once, sometimes combined with heavy nitrogen feeding — the inside grows faster than the skin — what Epidermis means can stretch. Leave it alone. Splits heal into scars on their own and should not be cut. If it keeps happening, ease off the water and give the plant somewhere to spend that growth, such as feeding for pups instead.

A tip has the growing point on it and carries on getting taller from that same tip. A mid is a section from further down with no growing point; it restarts by pushing new branches out of its areoles — what Areole means. A mid roots and grows just as well, it cannot etiolate at a tip because it has none, and it usually costs a little less. The only extra thing a mid asks of you is that you plant it the right way up.

For a tip cutting — what Cutting means, yes — and it is about the ratio, not the raw length. A bigger, fatter piece carries more stored energy and is far less likely to produce thin, weak growth while it roots. A rough guide: a two-inch-wide tip wants about two to three feet of length to be safe, and a very fat clone — what Clone means needs more again. Short tip cuttings are cheaper and easier to ship, which is exactly why they are common — and why they etiolate.

Three things move the number, and it helps to know them before you compare two listings. Size does most of the work, and the community's unit is inches, so read the length first. The name does the rest: a clone — what Clone means people are queueing for asks a great deal more than an easy-to-find one of exactly the same size, and a plant with no name at all sits below both. Then read the price line itself — a trailing "+" means postage is added on top, an auction figure is a starting bid rather than a sale, and a pack or lot price covers an unknown number of plants. What is fair is whatever a plant of that size, that name and that condition is going for the week you are buying.

It means the seller cuts the piece off the mother plant — what Mother plant means only after you order, so the two-to-three-week drying period happens after you pay rather than before. That is a good sign, not a bad one — it means the plant was alive on the mother until your order came in. Thick cuts take longer. You can usually change or cancel any time before the cut is actually taken.

You can, but add a heat pack — what Heat pack means, and understand the risk. Cold plus wet is the dangerous combination, and there is a documented case of cuttings — what Cutting means damaged in transit when the weather dropped from 40–50°F to 5°F while they were in the mail. Most sellers disclaim transit temperature explicitly and ask you to think about your own local weather before ordering.

Usually not. Outdoor-grown plants carry old healed bug bites, sun marks, corking — what Corking means and small scuffs — these are the marks of a plant that has lived outside and hardened off, and they grow out over time. What is not normal is soft squishy tissue, fuzzy grey mould, or a cut face that is not hard and dry. Photograph everything on delivery day and raise a claim within 48 hours if something is genuinely wrong — that is the window the Terms and the Returns page both give you.

Yes, for a few weeks. The most common way pests enter a collection is on a newly bought plant — eggs hide between the ribs and in the roots. Thrips — what Thrips means are the worst case: their eggs sit inside the plant tissue and their pupae in the soil, so a new plant can look completely clean under a magnifier and then erupt a week later.

Yes, and cutting — what Cutting means one usually gets you more plants, not fewer — a healthy column typically returns two or three new heads from a single cut. Take the cut when the plant is healthy, hydrated and the weather is good. Angle the cut so it does not form a little bowl that holds water. Sterilise the blade. Then stand the piece on a rack in shade with air all round until the cut face is hard, dry and shiny — reckon on about a week of drying for every inch of stem thickness, so two to three weeks for an ordinary cutting and longer for a fat one — before you plant it.

Probably, given time, warmth and food — flowers come in spring through summer, open at nightfall and are gone within about a day. Two things carry buds all the way through to open flowers: steady moisture and a phosphorus-rich feed. A plant that has flowered before will very likely flower again after being cut and repotted, so an old flower scar on a cutting — what Cutting means is a good sign. And some individual plants simply never bloom.

No. These cacti cannot fertilise themselves, and two cuttings — what Cutting means of the same clone — what Clone means are genetically the same plant — so no matter how many you own, they will never set seed with each other. A whole fence line of one clone can flower every summer for decades and never set a single fruit. You need two genetically different plants: two seedlings, or two different clones.

Grafting — what Graft means joins a piece of one cactus onto the roots of another so the top grows faster and fatter than it would on its own roots — what Own roots means. People do it for speed, to multiply a rare plant quickly, to rescue a broken piece, and to keep variegated — what Variegation means plants alive when they lack the green tissue to feed themselves. You do not need to do it — most of these plants root perfectly well on their own. It is a technique, not a requirement.

Only if you enjoy the process. Seed is much cheaper and genuinely rewarding, but it needs near-daily attention for months, and the plants take roughly ten to fifteen years to reach flowering. Buying a year-old seedling skips the slowest and riskiest year. And remember: because these cacti cannot self-pollinate, seed from a named plant will never give you that named plant.