This is what I would to if I were to start soft cuttings from HPs in the summer. Again, this is my own way of doing things.
They are called soft wood cuttings because the operation is done with trees that are growing. Not because they are soft wood, however, in this case they happen to be soft wood also.
You
will need:
1.
Rootone.
Found in every garden supply store next to the Miracle Grow. Not a
requirement, but it improves your odds greatly.
2.
A hybrid poplar tree .
Prepare a small corner of your garden, a place that you can keep shaded for a month or so, and ready it to plant petunias... that is, nice and fluffy to about 10" down, add whatever it needs to make it nice soil, if it has too much clay, add peat, vermiculite, sand or whatever. An alternative would be using pots with potting soil but make sure they are at least 8" tall.
Now, take as many cuttings as you need: branch endings are fine, so use the last 20" or so of every new branch. These will be 1-year old branches, without secondary branches, only leaves. Don't worry, the tree will not die because you are trimming a few branches, in fact if you take the whole tree down with a chain saw, it will start growing back right away.
From those branches make cuttings about 6" long. All cuttings have few leaves. - if they don't, discard, they're only sticks. Remove all but the top leaf. Remove also the buds except the one that still has a leaf. Now cut that remaining leaf so that only about 1/3 of it remains.
If you were to leave the leaves untouched and plant this cutting 2" deep, the very large surface of the leaves would use up the little internal moisture the cutting has, and the cutting would die shortly. We leave the minimum amount of green so the tree has a chance to grow roots that will start bringing chow to the rest of the tree, but it will be a few days before that rooting miracle happens.
At this point you cannot have a snack. If you do, when you come back you will have a bunch of dead sticks. Do the whole procedure from cutting the branches to watering the cuttings quickly and away from direct sunlight.
Dust the lower half of the cutting with Rootone (you can just dip it). Now slip the cutting in the dirt so that only the one leaf left shows. Notice that at the base of that leaf there is a bud. This is what will grow! Follow this procedure for all cuttings, planting them about 4 inches apart in all directions. 4 square feet is all you need to plant 50 cuttings. Tamp the dirt around the cuttings to remove any air pockets. Water well and you are done. Be sure no direct sunlight reaches the cuttings. Now you can have a snack. Water daily, twice a day if it is a hot day, if you have a sprayer, use it also. It will keep the leaves from dehydrating.
The
leaves will turn black and fall off within 4 days, and the buds will
start opening up by then. The fact that you see 8 or 10 leaves does
not mean that the cutting has any roots. Do not disturb and keep the
shade on at least for 1 month.
If
mother nature helps with rain, don't water that day. The amount of
growth depends on the month you started, the amount of water, the
temperature, and the amount of sunlight.
I received e-mail from a gentleman who told me Miracle Grow did wonders for his new trees (he had trees, not cuttings) . You can use miracle grow, but don't use for the first month or so. That would be like giving a triple dose of Viagra to an 18-year-old.
At the end of the year, and after all leaves are gone, just pull the trees out of the ground (the roots are not deep) and plant them wherever you wish. This time you don't have to worry about what kind of soil you use. They grow on just about any soil, just don't plant them in a place where your snickers squish.
You can do this with many different trees, plants and bushes, like forsythias, rose of sharon, weeping willow, hedges, and many others. Some day surprise yourself and try it with geraniums. or butterfly plant. It works!
This is the best I can do with soft wood cuttings. You may or may not get good results. If anyone has better ideas, I will put them here and give you credit for it!