How can I grow a Spiral Aloe from seed?
Aloe polyphylla, or commonly called Spiral Aloe, are notoriously difficult to grow from seed. Spiral aloes are native to the mountains in the country of Lesotho, completely surrounded by South Africa, so while they are hardy in USDA Zones 7b to 10b, they aren’t forgiving of anything outside that firm bracket.
If you are in Westchester and are trying to grow this plant outdoors, that small difference may be one big reason why you’re not having the results you want. If you aren’t sure of your Zone, you can find it by going to http://planthardiness.ars.usda.gov/PHZMWeb/ and entering your ZIP code in the little box near the top of the left side of the page. If your Zone is less than a 7b, which is warmer than a 7a or any lower number, you may be doomed to disappointment.
In the same vein, this plant won’t tolerate many days of temperatures exceeding 80 degrees Farenheit, so too much heat can also be a problem. Those heat waves we’ve had at the beginning of the last few summers could have done your seeds in. A. polyphilla simply isn’t willing to venture much outside its comfort zone. If days in your area will regularly go above this temperature at any time of year, you should put it in a thick container made of wood or glazed ceramic and set it in filtered sun until the days cool down.
Another culprit could be too little drainage. Not only are they succulents, that survive by holding moisture, but these are also originally mountain plants, so they are used to being in a place where the soil drains freely down the slope. Overwatering can kill them with kindness.
If you are starting them in a pot, be sure it’s not too large for them, as this can cause them to rot before they can roll. Both the width and the depth of your container are important. Although these aloes can develop a deep root system eventually, you should gradually increase the size of the pot, instead of giving them a deadly palace too early in life.
Hope this helps.