I have been wondering, would there be any difference in rooting hardwood cuttings in an unheated garage, rather than an outside cold frame?
Light is the biggest factor of a garage vs a cold frame.
Use a thermometer to check temperatures and add a grow light for an garage location.
https://www.gardeningknowhow.com/ornamental/trees/tgen/how-to-root-cuttings-from-various-shrubs-bushes-and-trees.htm
My pig's ear plant has a baby growing out of the soil very near the stem. Should I pull it off and replant?
The baby could probably be separated and planted successfully. Try to get some roots with it that may already be growing. If it doesn't have any roots, you can treat it as a cutting:
https://www.gardeningknowhow.com/garden-how-to/projects/rooting-plant-cuttings.htm
In what soil must we root cuttings of oak and black walnut?
Here are some links to help you.
https://www.gardeningknowhow.com/garden-how-to/projects/rooting-plant-cuttings.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/how-to-root-cuttings-from-various-shrubs-bushes-and-trees.htm
Can honey be used to make a rooting agent?
Yes, honey is a very popular natural rooting agent. This article covers a few ways to do it: https://www.gardeningknowhow.com/garden-how-to/propagation/cuttings/honey-root-hormone.htm
How to start ? Yellow branch ? Fori???
This article will help you with propagating by cuttings.
https://www.gardeningknowhow.com/garden-how-to/projects/rooting-plant-cuttings.htm
Can I start a weeping maple tree from a branch?
Yes, you can. The best way to do it is to take a softwood cutting, as explained in this article, and encourage it to grow roots:
The rooting hormone will help, but most cuttings will root without it, so it's optional.
How much protection do young clone plants need