Hybrid poplars are usually propagated by taking cuttings from a locally grown poplar. Using this method, the trees produced will be the exact clones of the mother tree. The process is not complicated, but certain steps need to be followed to have a successful rooting.
Cut sections of the hybrid poplar from one-year-old wood, which will have had a chance to harden off, and is usually easily rooted. Make the cut at a 45-degree angle to the branch and remove about 12 inches. Typically this is done in early spring before the tree has started budding out.
Soak the cuttings in cold water for two or three days before planting. About one fourth of the branch should be in water to encourage the rooting process. This is especially important for cuttings taken late in the spring.
Prepare the planting spot by cultivating it and removing any rocks or debris. If you are planting several cuttings, they should be spaced about 4 feet apart. Work the soil down at least 12 inches and make sure it has plenty of organic material in it to hold moisture.
Push the damp cuttings into the soil straight up and down, leaving only an inch of the cutting sticking out of the top of the soil. Make sure the soil is damp, and firm it up around the cuttings to make sure there are no air pockets.
Water the cuttings as needed to keep the soil damp for the first three or four weeks. The cuttings should root quickly and show signs of growth. Keep weeds removed from the area around the base of the cuttings.