Fruit, and the seed inside it
The green lump behind the dead flower: what tells you it is ripe, why you cut it off instead of pulling, and the fifteen minutes of washing that decides whether your seed is still alive in two years.
7 min read6 sections
A fruit is not a new organ. It is the swollen base of the flower — that green lump was sitting behind the petals the whole time — and once pollination has taken, it simply carries on growing while the flower above it dies off.
It comes out hairy, because everything on the reproductive end of these plants is. A hairy bud with a hairy fruit behind it is the easiest field check there is for a true .
When is it ready?
- **Firmness first.** Rock hard means no. A little give means close.
- **Colour is a trap.** It only tells you anything on clones whose fruit changes colour — some ripen yellow, some go red or burgundy. Plenty of Trichocereus fruit stays green right through and is perfectly ripe.
- **The real signal is the fruit splitting itself open.** The inside outgrows the skin and it opens along a seam. That is ripe, and no judgement is required.
Rock hard
not yet
A little give
close
Split along its own seam
ripe · no judgement required
Getting it off the plant
Cut, never pull. An that has flowered can flower again from the same spot — unless you tear the fruit off and bring the growing point with it, which is the one way to permanently lose that flowering position.
Spoon it out, leave the shell
areole intact
Take the whole fruit
leaves more of a mark
Spoon it out, leave the shell
Open the fruit where it stands and scoop the pulp and seed into a pot. The shell stays on the plant and dries off. Much less scarring, and the better habit on a plant whose looks you care about.
Take the whole fruit
Cut it away at the base with a razor blade. Faster, and the only realistic option on a fruit you are reaching for at the top of a pole pruner — cut behind the base and catch it. It leaves more of a mark.
Spoon it out, leave the shell
Open the fruit where it stands and scoop the pulp and seed into a pot. The shell stays on the plant and dries off. Much less scarring, and the better habit on a plant whose looks you care about.
Take the whole fruit
Cut it away at the base with a razor blade. Faster, and the only realistic option on a fruit you are reaching for at the top of a pole pruner — cut behind the base and catch it. It leaves more of a mark.
What is inside
A few hundred seeds in a small fruit, up to around two thousand in a good one, all of them embedded in pulp that they will not survive being left in.
One thing worth knowing before you start throwing seed away: if every seed in a fruit is tiny, that is normal for some strains and they are viable. It is a few tiny ones among normal-sized seeds that are the duds.
Cleaning, which is the part that matters
Step 1: Break the pulp up in water
A bowl of water and your fingers. Work the lumps apart until the seed is loose.
Step 2: Rub it against a plastic sieve
Under a slow tap. Plastic, not metal — a metal mesh is abrasive enough to damage the seed coat — and keep the flow gentle or you will lose half of them over the rim.
Step 3: Dry it flat, twice
Spread the seed as thinly as you can on paper towel, press more towel down on top, then repeat once or twice on dry towel. Skip this and the drying pulp glues the seed into lumps you will never separate.
Step 4: Shed the dust
Tip the dry seed from one clean plate to another a few times. What comes off is pulp dust.
Step 5: Disinfect, if you want to
Thirty seconds to a minute in neat 3% hydrogen peroxide, then rinse thoroughly — it also loosens the last of the sticky residue. Rinse your fingers too.
Step 6: Bin anything that touched mould
Or at the very least keep it in its own envelope, labelled, and sow it away from the rest.
One — break the pulp up in water
a bowl, and your fingers
Two — rub it against a plastic sieve
plastic, not metal · a slow tap
Three — dry it flat, twice
thin layer · press · repeat
Cleaned and dried
loose · glossy · pours
Never washed
tacky · clumped
Storage, and the truth about the word fresh
For about six months seed needs nothing special. Past that, store it properly or it fades: a glassine envelope inside an airtight jar with a very small silica gel sachet, kept dark and cool. A big sachet is worse than none, because it pulls the air too dry.
Kept that way, seed still germinates four years on, at a rate that falls the whole time. One grower's own hand-pollinated seed, cleaned and stored carefully, showed no measurable drop at eighteen months.
And the blunt version, because it is the most useful sentence in this guide: old seed is the commonest reason a sowing fails, and almost every shop describes its seed as fresh. Buy from whoever produced it, and ask what year it came off the plant.
What the seed will be
Every one of them is a new individual. The mother is the plant that carried the fruit; the father donated the . Growers repeat a rule of thumb that the mother's traits dominate at roughly two parts to one — worth knowing as a hedge rather than a law, because it is a pattern people have noticed rather than anything measured.
Siblings out of one fruit differ in shape, in vigour, and later in the size and shape of their own flowers. If you want them to be alike you want . If you want them to be interesting, this is how you get that.
Nobody grows these for the fruit, incidentally. It is hairy and mostly seed, and the growers who make the most of it keep it for exactly that.
Quick check
Did any of that land?
Question 1: What is the definitive sign that a fruit is ripe?
Question 2: Why cut a fruit off rather than pull it?
Question 3: How should cleaned seed be stored past six months?