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Repotting Mistakes 101 (don't you do this)
� How to mix potting soil from store bought material

� How to repot a root bound cutting into a larger pot
... i recently bought 6 peruvianus cactuses from your site. i quickly repotted them using screened soil composted from yard clippings (they give it away at our local dump). i mixed the compost with sand, perlite, and peat moss at the ratios recommended on your site. .. i am watering them once a week with water mixed with one tablespoon of all purpose miracle grow fertilizer. the cactus's are receiving about 4 hours of direct sunlight per day...a small spot just about an inch above the dirt, the skin has turned a pale brown color and seems to be dead. under the "dead" skin, the cactus looks to be rotting. i dug down into the dirt, and this seems to have extended down below the soil towards the roots. i dug around the rest of the base, and the rest of it looks healthy... and overall, the cactus looks healthy and strong. it's just that one small area that is unhealthy.

do you know this is and what might have caused it?... what can i do to prevent it from getting worse?

Don't repot a large specimen immediately after receiving it. Plants live by their roots which include thousands of fine hair thin roots that branch off the large, visible ones. Handling the specimen for packing, shipping, and unpacking is going to break/disturb many roots. Allow a recently shipped plant to sit quietly in a shady location for a week or two to recover.

Don't use yard waste as "compost". That stuff is horribly toxic and suitable only for use as mulch around shrubs or trees. I know what I'm talking about from direct experience.


You obtained this material (so called compost) from the "dump". I've been to that very same dump because I used to live in Mountain View, CA where you are. The city is constantly trying to get residents to take this "free" compost as part of their efforts to reduce landfill. But it is NOT compost - it is like foul smelling, steaming hot shredded wood with sewerage sludge.

The "yard waste" is not just grass clippings. I used to see what Mountain View residents put in their YARD WASTE RECYCLING TOTES. I saw drywall, plywood, tree branches, along with noxious plant oils from pine (terpenes) and oleander. People dump all sorts of crap in them as a way to avoid paying for trash pickup.

The City Dump shreds all that to "compost it" only it won't decompose because the huge amounts of wood (carbon) requires an added source of nitrogen - lots and lots of nitrogen. Know how they do that? They use another waste produce; sewage sludge. That's right - foul smelling concentrated sewage - which is very high in nitrogen.

I drove to that same dump you went to with a helper about 9 years ago to get a pick up truck load of the "free compost". The smell was terrible. The stuff was not composted - it was hot, fresh and smelled bad! It looked like black shredded wood - wood is something you never want to put in plant soil because it robs nitrogen, from the plants, in order to feed the micro-organisms to break it down. Underneath the soil those pieces of wood will rot by anaerobic fungal/bacterial activity; tying up nitrogen that the plant needs.

The stuff was unfit to put into the soil of a garden - instead I used it to mulch along a driveway around shrubs and rose bushes. It took a year or two for my local bugs & microbes to digest it. I never went back to that dump for any more "free compost."


13190. (b) "Compost" means the product resulting from the controlled biological decomposition of organic wastes...

When you get compost from the city dump it is steaming hot because it is NOT yet compost! It is carbonaceous material heated up with added nitrogen to activate thermophillic bacteria. That hot product from the dump is the verb composting; as opposed to the noun compost.

Organic compost should sit and age for a year. After the initial heat dies down it will "cold compost" with worms, insects, fungus, etc. - a complex world of micro-organisms. These are an essential element for organically healthy soil.

City dwellers can't make piles comprised of many tons of material that have to sit for a year. That is why I advise buying a potting mix. Screen out the wood as shown in my tutorial.
Real compost is humus - the fine, spongy stuff you find under the leaves of a forest floor. But yard waste compost is shredded wood drenched in sewer sludge. And you think this is "compost?" If you read my articles about this subject and my enclosed literature I clearly state that real compost is out of the reach of people living is cities, etc. For that reason I recommend buying bagged potting mix.
My directions are to buy potting mix, then screen out the wood as shown. Also, use coir - not peat moss because peat moss supports some diseases. Coir is better and helps with small root growth.

Plants have an immune system and heal themselves
Apparently you rushed to repot the specimen in toxic sewerage sludge yard waste. Then you found a "brown spot" -that is a bruise - just like when a human gets a bruise. You should leave such things alone, don't pick at it, don't dig up the roots, etc. Picking at brown spots and digging up the roots invites infection. When left alone bruises turn into the tan colored scabs commonly called blemishes on a cactus.

Transplanting guide, summary of recommendations for city dwellers

� Allow a new plant rest after shipping - to heal any broken roots.
� Do not use what "you think is compost" for repotting soil because it isn't.
� After repotting let the specimen rest in a shady area without watering for a week.
� Small "brown areas" may be the surface appearance of a bruise (mechanical injury).
� Introduce the plant to full or direct sunlight gradually to avoid sunburn.
� Don't obsess on blemishes, tip pimples, bruises; the plant is not a statue. It'll grow huge.
� Never perform "surgery" to cut out bruises - that introduces infection.
� After watering let the soil dry out (stick your finger in the pot) then water thoroughly.

You probably bruised the plant during repotting by mechanical injury to the tissue.  After potting I move plants to a shady spot to recover without watering for about a week. This allows any broken roots to heal before watering the plant. Don't repot a large columnar cactus and immediately water it.  Itsa cactus and doesn't need water right away as would a deciduous tree or shrub.

Don't pick at scabs
You picked at the "small brown spot" because you state that under it you found it rotting. Well... it was simply dead tissue and the plants immune system will take care of it. LEAVE IT ALONE! Bruise heal to become hard tan colored blemishes. They are normal.

After repotting in toxic yard waste sludge, bruising the plant, then picking at a small bruise to open it to infection, you dug into the roots to disturb them, then you began watering & feeding fertilizer. It needs to rest & recover - the last thing the cactus needed was a shot of fertilizer.

4-hours a day of light?
Inadequate light is an invitation to a sickly plant. My 3-page cactus guide (included with orders) has a paragraph about light on the first page. Cactus need bright light but not all day direct sun. Read the advice in my handout.

This essay is public to serve as a reference to others. I emailed to the customer my money back guarantee. While I don't mind fully explaining this once for everyone - I cannot write all this information to only one person, then have to explain it again, and again to another person. Please use this as a reference on what happens when an inexperienced person ignores my repotting advice and makes up their own rules. Oh, well.

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