The following is a copy of information provided to me by Alan C Beverly of Ecoscape Nursery, a specialist in the growing of Spiral Aloe, Aloe polyphylla.
Cultivation of Aloe polyphylla from seed - Fall 2020
Alan C Beverly - Ecoscape Nursery
424 National St. Santa Cruz CA 95060
This seed was harvested In Aug-Sept 2020 and stored at refrigerator temperature. It is hybrid seed produced by hand pollination of differing genotypic parents. Other researchers (Royal Botanic Garden Edinburgh) have found that a good way to proceed is to soak the seeds in water for a few weeks until the root begins to emerge. Then transplant the germinated seed to real media to establish a seedling. I have performed a partial scarification using 150 grit san paper to break the outer dry "wings" to facilitate imbibition of water before planting the seed into the media. This facilitates faster germination but exposes the endosperm to micro-organisms which kill the seed. There must be an anti-microbial compound in the seed coating (wings) that protects the seedling. As each seed germinates remove it from the water and place into shaded media. Do NOT cover the seed with mulch. The root emerges and the first seed-leaf is formed. The root descends into the soil but may not find sufficient spaces between the soil particles to descend, resulting in the seedling lifting itself up. This is the critical moment to help the seedling to establish a downward pointing root in contact with soil and the reason I recommend using no organic matter, only red lava. You may want to manipulate seedlings which have a looped root to help establishment. In week 4 you will want to watch and manipulate each seedling carefully to anchor the root. Grow-lights and a fan on a 16-hour day length are helpful. You may begin to use a crystalline fertilizer such as Miracle-Gro at label rate. Recent trials are showing that 100% red lava, 8mm (5/16”) washed, offers the best result. When the first root begins to explore the soil, the soil must conform to the physiological needs of the root tissue to provide enough oxygen. Only COOL soil temperature fosters seed germination, bottom heat is NOT necessary. Temperature range of 4-21°C (40-70°F) is suggested. When the first cotyledon leaf is formed with a root your seedling is beginning to establish itself. The soil media as prescribed has little water holding capacity, and your seedling wants a very porous soil now, so decrease water applications to about 1x/3 days lightly.
At the 4-leaf stage you may safely transplant seedlings to increase personal space required for plant development. The media should be 50/50 red lava and perlite. Do NOT overwater believing it to be essential to the seedling. This is just one of the counterintuitive factors I have come to realize growing this species.
Cultivation of Aloe polyphylla - Fall 2020
Alan C Beverly - Ecoscape Nursery
424 National St. Santa Cruz, CA 95060
Thanks for your business and interest in Aloe polyphylla. Here is a brief set of instructions and caveats to start your journey of wonderment growing the Spiral Aloe. Please visit our website for updates and more information.
1. Soil Mix: I have experimented with several concepts of soil formulae and now recommend this: Very Little POTTING SOIL- Use 50% RED LAVA, 8mm (5/16") washed, and 50% #3 PERLITE. For tub specimens this is amended to read 100% 19mm (3/4") red lava, with some potting soil (10%) and/or perlite permitted.
2. Prevent the soil temperature from going above 27°C (80°F) by using a large container of ceramic, wood, or terra cotta. Overpotting is the rule for good growth. The leaf tolerance of high air temperatures is much higher than the root’s tolerance.
3. Plant must have some outdoor light quality with UVA, UVB radiation to achieve good spiral form. Remember that it is infrared radiation which heats up the container, but that UVA & B radiation is the energy which drives photosynthesis.
4. Use only water you would drink and enjoy, No chlorine, No salt, Not alkaline. No graywater.
5. Adult plants with 150+ leaves have a rated hardiness of -12°C (10°F) if winter sun is ~6 hours/day. Juvenile plants have less hardiness and should be protected.
6. Organic materials fertilizers are NOT safe. The added microorganisms are facultative, meaning they can act as both a pathogen or in a saprophytic benign behavior. No osmocote, No salty granular formulations. I use Miracle-Gro at 1 teaspoon/gallon only (this originally said 1 tablespoon/gallon but that seems excessive. I suggest clarifying this with Alan C. Beverly).
7. Be watchful of ant activity and use chemical warfare to kill and deter them and aphids and mealy bugs by using 1% soap with some pyrethroid additive. Mites have proven to be a major threat, see #14
8. Never pull off a leaf with tip necrosis mid-spiral. The only plant grooming is to pull off the lowermost leaf when paper thin. The plant will release its hold on it when the goo is resorbed. At a maximum size of ~175 leaves the dynamic ratio of new leaf creation to old leaf retirement is 1. Fusarium infection of roots alters this ratio to less than 1, and mites in the root stump do the same.
9. Healthy roots are yellow, dead roots are brown. Some live older roots will have a brown color due to suberization . If the plant collapses pull it up, clean off the dead roots, jet wash, scrape the root stump with a penknife down to hard tissue, removing all dead tissue. Let the plant dry before replanting on moist soil in shade. In 2-3 weeks, new roots form. I call this plant rehabilitation and is a normal and expected event in the life of A.p. Adult container specimens require this every 5 years. Do not water the plant until a "push test" proves that new roots have formed to grab the media, creating resistance to push or pull. Healthy roots require much oxygen to inflate each leaf. High soil temperatures and/or flooded soil will suffocate the roots.
10. The above recommendations are written with reference to container plants. In the landscape a mound of sandy loam free of root competition from other plants will be a good start for 65-75 leaf plants and diminish concerns of high soil temperatures.
11. I warranty each plant for 60 days after shipment. If you follow instructions and your plant suddenly dies, I will send another only if you provide a pic via email of the plant. Upon receipt, expose the plant to air and light, there is no immediate requirement to install in the specified media. Prepare the media and water it. Place your plant high in the center of your container and wait several weeks for new roots to form. You may apply liquid fertilizers at this time.
12. I enclose a sample of the media to show just how radically different it is from other commercial "cactus & succulent" media. It is closer to what is used in hydroponic grow systems than any media specification you have seen.
13. Your plant has been treated with systemic insecticides and miticides to protect it against the Springtails (Collembola) and the Eriophyid mites which may inhabit the root stump. The Springtails are easy to eliminate, but the red mites are very small and cause a very big problem for A.p. The mite adults are visible with a hand lens, but the larvae measure in at about 250 microns, making them invisible to even those with hand lens. They occupy the live/dead tissue boundary in the root stump. A mite-infested plant will die slowly from symptoms which mimic death by Fusarium. After 30 years of dealing with this I'm convinced that the major pest of A.p. is actually the red spider mites, and not Fusarium, which is now listed in second place. Most other Aloes in Southern California can be plagued by subcutaneous mites which generate a hyperplasia (tumor) easily viewed. There is NO CURE. Prevention is then the only strategy. Abamectin is one miticide but is not systemic. Spirotetramat is a systemic miticide. The use of essential oils such as garlic, clove, rosemary, and castor (Mite-X) has value in surface treating the root stump by soaking for plants undergoing a rehabilitation procedure. The Orange-guard product has limonene which is also good. For A.p. infected with red mites there is a stasis reached where they simply stay put in the root stump. They cannot live outside of the root stump, like termites, are very vulnerable to desiccation and UV light. Plants so infected may begin to lean to one side and have an altered dynamic leaf ratio, losing more leaf than are being grown. This is all you will witness unless the mites are disturbed by carving back dead tissue of the root stump to reveal the live/dead tissue boundary. I cannot report any success to spray or soak mite infested plants with any miticide.
14. I receive many questions regarding tip necrosis. This is the effect of a limited soil volume, insects, or the Fusarium fungus. If the symptom occurs only on the oldest leaf, then this is considered a symptom of pre-retirement of the leaf, but if this occurs in mid-spiral with larger lesions then I would recommend pulling up your plant and inspecting closely for insects etc... clean dead tissue, jet-wash, and re-root. The root stump should be hard. If soft, cut away all soft tissue, spray with an aerosol insecticide and re-root.