Yes, you can propagate succulents fallen leaves if the base of the leaf stayed intact when it came off. The key is that tiny bit of tissue at the very bottom where the leaf connects to the stem. That tissue holds the cells that grow into new roots and plantlets. Without it, your leaf will just dry up and die.
I find fallen succulent leaves under my plants all the time. Some of them root just fine while others shrivel up with no growth at all. The difference comes down to one thing. Leaves that fell off clean with their base intact tend to work. Leaves that tore or rotted off at the stem leave that crucial tissue behind and they always fail.
The tissue you need is called meristem tissue. Think of it like stem cells for plants. These special cells can turn into roots or new leaves as needed. Iowa State University Extension explains that the entire leaf plus the cells where it attaches to the stem must be there. Fallen succulent leaves that broke off clean still have this tissue and can grow.
Leaves fall for different reasons and each reason affects your odds. Healthy leaves that got bumped off work best. Naturally dropped leaves propagation works when the tissue stayed intact. But leaves that dropped due to rot lost their base tissue to that damage. The plant cuts off dying tissue to protect itself.
Check your succulent leaves on ground before you try to root them. Look at the bottom edge where it attached to the stem. A clean curved edge means the base stayed intact. A torn or jagged edge means tissue got left behind on the mother plant. A dark mushy spot means rot got there first. Only the clean ones are worth your time and effort.
Leaves you pull off yourself have better odds than ones that fall on their own. When you twist a leaf off with a gentle side motion the whole base comes with it. You get that meristem tissue every time if you do it right. Fallen leaves give you about a 50% success rate at best. Pulled leaves hit 80% or higher in my experience.
Collect your fallen leaves anyway since some will work. Just set your expectations lower than with pulled leaves. Put them all on a tray and see which ones show signs of life in 2-3 weeks. The ones that work will push out pink roots or tiny baby leaves. Toss the ones that shrivel since they never had a chance in the first place.
Read the full article: 7 Steps for Succulent Leaf Propagation Success