Discussing toxic plants is always a bit complicated.
You might think it would be cut and dry, that a plant is either toxic or it is not, but it isn’t that simple. Plants can have both toxic parts and safe parts, for example, can be safe to eat in modest quantities, but toxic when too much is consumed, safe at certain seasons and toxic at others, or again, can be toxic raw and safe or even edible after cooking. When I published a list of 200 Poisonous Houseplants a few months ago, for example, I specifically included plants that could be toxic if nibbled on by a child or pet. It was not intended to be a condemnation of a plant’s toxicity under all circumstances!
Aloe: Both Harmless and Toxic
The highly popular medicinal aloe (Aloes vera), generally called just aloe, is a good example. This popular houseplant (in cold climates) and garden plant (in mild ones) is perfectly safe to use, even internally, when you know what to do, but irritating and somewhat toxic (plus highly bitter) if not used carefully.
The part you want is the clear gel inside the leaf, used to reduce the pain of scrapes, minor burns and cuts, etc., and to help quicken healing as well as, internally, to soothe the gastrointestinal tract. However, just inside the leaf, there is a narrow band of yellow tissue that gives off a toxic, bitter sap due to the presence of aloin. You don’t want to use that!
It’s therefore not wise just to cut off the tip of a leaf and squeeze out the gel like so much toothpaste. Than can release aloin along with the gel, resulting in irritation. Rather than squeeze the leaf, harvest one (or part of one) and cut it open. Here’s how:
Put on a pair of gloves (aloe leaves have spiny edges—not wickedly prickly, but still!) and pull a healthy leaf back and forth until the leaf pulls free. Some people prefer to cut the leaf free with a sharp knife.
Use the same sharp knife to “filet” the leaf, cutting off the green and yellow layers on top. Now simply scoop out the gel with a spoon, leaving behind the lower layer of gel, closest to the rind.
If you only need a small amount of aloe sap, after you harvest the leaf, cut off a small section and only filet that, wrapping the rest up in plastic wrap. It will store for 10 to 15 days at room temperature or for 20 to 25 days in the refrigerator.
You can store excess aloe gel in a container in the refrigerator for 3 to 4 days. There are also treatments you can use to make the gel last even longer, like mixing in vitamins C and E, but I find an aloe plant produces enough leaves that it is much easier just to harvest a new one than to use complicated procedures to extend the use of gel you’ve harvested.
To learn how to grow an aloe plant, read Save Money: Grow Your Own Aloe.
Enjoy growing your aloe plant. It’s an attractive and easy-to-grow plant, practical to have on hand for minor medical emergencies. I just hope you don’t need to use its gel often!