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Disease | More about disease | Insects | Tip pimples | Obsessing over your plant | Insect myths
Tip pimples & zits are not rot
As a grower I observe my plants. From observation I try to form a picture of what nature is doing. I cannot say what is going on beyond these observations. But I will not offer theories of fungus, insects, etc. because I have no proof or evidence of those.

These examples of tip pimples, bruises and black spots are not rot. Rot is a malignant disease that will spread like gangrene to kill an entire cutting.
This page is not about this! (left)
That is rot; everything turns to brown slime. It spreads from one end to the other of an infected cutting by overwhelming the plants immune system.

It can travel up from rotting roots and spread through the core of cuttings. It is common during the rainy season or in winter when the plants are dormant. I no longer take cuttings during the winter or during cold, wet weather because of the problems with rot.

Rot has one cure; amputation. You have to cut well ahead of its spread to save parts of a plant not yet destroyed. If roots or lower portions begin to rot you should cut off the upper sections to callus and save for replanting.

Please keep this in perspective!

Your cutting is a baby that will grow into a cluster of columns the mass of an SUV and the size of a tree. Obsessing over juvenile stage blemishes is silly.

New growth tips are vulnerable to injury but soon toughen up. Harvesting, callusing, shipping, and rooting are the tender stages. All new growth will be blemish free if you protect your plants from mechanical injuries.


"Well its been building up inside of me
For oh I don't know how long
I don't know why
But I keep thinking
Something's bound to go wrong

But she looks in my eyes
And makes me realize
And she says "don't worry baby"
Don't worry baby
Don't worry baby
Everything will turn out alright"

Brian Wilson

A) SPONTANEOUS TIP PIMPLES ON NEW GROWTH TIPS

Leave this alone; no fungicide, no insecticides!

Shortcut for those who don't want to read all this
• Don't worry, don't obsess
• Do nothing and it will run its course and go away

1) Tip pimples will appear on both cut and uncut tips. They will appear on rooted, healthy plants.
2) Tip pimples seem to appear when there is very rapid growth, in summer, from a heat wave. After sudden jumps from 90 F to 107 F many plants developed rashes of tip pimples. Yes, even on ones cut and being allowed to callus.
3) Tip pimples can fade away.
4) Tip pimples can leave behind a v-shaped scar similar to "stretch marks" in human skin.
5) They appear on cut tips if the spines are allowed to scratch adjacent tips--this occurs anywhere on the column scratched by another--something like a rash, or small local scratch.
6) Scratches heal to form tan colored scars, tip pimples can fade away or leave behind the v-shaped scar marking that year's growth spurt heat wave.

B) INJURY MARKS ON NEW OR OLD SECTIONS

Bruises such as this example will normally not spread.
This is NOT rot. Do not use any fungicide, etc. In this particular example the little bud should be snapped off and the log (column section) rooted. In the future plenty of new buds will form.

1) Mechanical injury such as bruising or punctures can result in a black area. This is similar to a bruise on a person.
2) Punctures or bruises form more easily on young, new growth tips. But old, thick columns can be bruised--but it takes more mechanical force to injure one.
3) The aftermath of an injury bruise is a scar.

C) BLACK PUSTULES APPEAR INEXPLICABLY ON PLANTS

(left) This may be a fungal disease such as "black spot".
I have never used a fungicide; it always stays localized and runs its course. Why? Because a healthy plant has an immune system and can heal itself.

How this occurs on one out of 50 similar plants under similar conditions is inexplicable. The black spots heal into tan colored scars.

(above) one of my plants.
(below) photo emailed from unknown person.

1) A rooted plant one day shows a black spot. This can grow, swell, spread, and even weep liquid.
2) Pustules can appear on one plant but not affect ones growing nearby under the same conditions.
3) Pustules can occur during the dormant period when the plant is not being watered, or in the spring or autumn. They seem less common during the growing season.
4) Pustules can flow downward on a column.
5) Pustules can be cut open and drained, flushed with alcohol.
6) Pustules can be left untreated.
7) Every pustules on my plants has "run its course" as a localized infection. The aftermath is a tan scar.

Close up of the plant at left. I do not know what the person did to make this plant so unhealthy, but the twist tie holding it up is a big hint that this was a sick plant.


Tip pimple photos

Tip pimples can be like stretch marks.

They seem to form in the delicate new growth tissue of a "growth spurt."
Some scabs can be picked off

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