Troubleshooting common issues

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Symptom- dark brown or black discolored spot, squishy. Cause- Rot. Too wet for too long, too low of temperatures, or other untreated infection gone wrong. Treatment - cut out rot with a sharp knife. Disinfect knife with alcohol before each individual cut. Cut until no discoloration on inner flesh is visible. Dust cuts with sulphur powder and let dry. Reduce moisture, identify and treat causes of the rot.

Symptom- raised blister. Sometimes matches green skin coloring, sometimes black. Can be oozing black. Cause- Oedema, aka “humidity spots” or “humidity blisters”. Roots are drinking and pushing more moisture into the column than the pores on the skin can exhale. Treatment- make sure to wait until the soil is dry beneath the surface before watering again. Make sure humidity is low enough during the day and that there is airflow. Do not treat columns with oil products - can block pores from exhaling properly. Make sure the soil substrate has sufficient air filled porosity and drainage.

Symptom- In seedlings, red coloration all the way around the column showing from the base going up. Tip not red or less red. Cause- phosphorous and/or potassium deficiency. Treatment- use a well balanced fertilizer.

Symptom- yellowish discoloration through the lower portion of the column, all the way around. Cause- nitrogen and/or calcium deficiency. Treatment- Apply a well balanced nutrient fertilizer.

Symptom- yellow or red discoloration focused on protruding portions of ribs, tips, and around areoles, facing the sun. Cause- sunburn. Treatment- provide shade for a few days. Burned areas may scar. Make light reintroductions gradually.

Symptom- white fuzzy clusters on column, around areoles and between ribs. Alternatively, on roots.

Cause- mealybugs Treatment- isolate affected plants. Remove and discard soil, inspect roots. Scrub mealies away with a toothbrush and alcohol. If you can get it, Imidacloprid.

Symptom- small circular white or tan scab looking spots with darker centers. Possible cause- scale insects. Treatment- scrub with toothbrush and alcohol. If they easily dislodge, likely scale. If they do not easily dislodge, they could instead be scarring or a fungal issue.

Symptom- scarring or small chunks missing from the tip. Cause- “Tip nibbler” class of pests. Grasshoppers, slugs, snails, earwigs, even rodents. Treatment- First, identify the pest. Treatment will depend on pest type. Check under pots for slugs or snails, to treat try Sluggo. Sluggo Plus adds earwig control. For extreme measures, foliar feeding a mixture of water soluble gypsum and/or Epsom salts will leave a powder residue on plants that tip nibblers do not like, but will leave plants ugly and with permanently damaged farina. Sometimes you just have to accept that living with your local ecosystem means your outdoor plants will occasionally be food.

Symptom- very tiny speck like insects. Diagnostic- It is important to identify insects before arbitrarily applying insecticides. Try blowing on them. If they jump when blown on - springtails. Springtails are beneficials. Non jumping, fast moving speck like insects that do not fly- predator mites, another friend. Other beneficials include worms, spiders, lacewings, ladybugs, praying mantis. Treatment- these are signs of a healthy ecosystem. Leave them be, they will not harm your plants.

Symptom- small discolored specs on column, or a tan crust like area. Cause- “Sucker” class of pest insects. Slow moving speck like insects that do not jump with no flying insects present could be bad mites. If very fine webbing is present, possibly Spider Mites - but dont confuse these with tiny spiders. If insects are oblong shaped and flying insects are also present, could be Thrips. Use yellow sticky traps to help detect and identify thrips. Also, Aphids. Treatment- Spinosad spray concentrate (Monterey garden insect spray), alternatively flying skull nuke em works similarly with a different active ingredient. These are food safe and kill any insects that try to suck juice from your column. Apply every 4-5 days, for 4-5 applications to disrupt egg, larvae, and adult life cycles. Only apply at dusk or risk wet droplets of spray magnifying light and causing small black burn marks on columns. Another effective treatment is releasing beneficial predatory insects, such as ladybugs, mantis, preditory mites, or lacewings.

Symptom- skinny new growth at tip.

Cause- etiolation. Typically due to lack of sufficient light. Also can happen to cuttings while they are rooting.

Symptom- wobbly columns or seedlings want to tip over. Cause- typically older etiolation. Long term insufficient light. You can try to prop the columns up with bamboo skewers or garden stakes, but typically they eventually will need to be cut and rerooted or logged so they can regrow fatter growth that can support their own weight.

Symptom- reddish orangish specks, or even larger patches.

Cause- rust fungus. Treatment- copper fungicides can be tried, but typically are too weak to affect an active infection. Mancozeb is a stronger alternative, but read and understand the label before application.

Symptom- concentric circles, alternating tan and dark brown/black. Cause- alternaria fungus. This is an aggressive spreading, dangerous fungus. Treatment- Isolate the plant. Mancozeb, garden phos/phos acid, consider cutting or disposing of the plant in severe cases, if you do, also dispose of the soil and sterilize the pot before reuse.

Symptom- black tip or spots between ribs with purpleish hue, oozing.

Cause- Bipolaris fungus. Aggressive, dangerous, fast spreading fungus. It will enter the core and rapidly spread under the skin to kill the whole column. Loves warm humid conditions. Looks similar to rot, but look for that blackish purpleish color hue to differentiate it from the brown or slightly translucent darker green of rot. Treatment: Immediate surgery required. Be sure to sterilize cutting utensil between cuts and to get it all out from the center to prevent it spreading further. If internal discoloration extends through the whole column, dispose of the plant and soil, sterilize pot.

Symptom- pups on pups on pups. Abnormally fuzzy areoles. Pups out of every areole on pups.

Cause- Witches Broom. Phytoplasma infection spread by pests. Highly contagious. Not to be confused with normal or stress induced monstrose growth.