@kalikuma For maximum fullness, cut your plant back closer to the soil line - maybe 3" from the soil line. You'll get a number of new branches/stems in almost all if not all of the leaf axils (crotch formed by the leaf petiole/stem and the main stem). After a while, when new branches have lengthened and thickened, you can cut those back and they in turn will also back-bud and produce branches.
There is a chemical compound/ hormone/ growth regulator (auxin) produced near the tip of the stem. One of this growth regulator's primary functions is suppression of already existing buds located above every leaf and/or leaf scar left after a leaf has fallen.
Here ^^^ yiou see both leaf scars and suppressed buds. If you were to cut the tip off (pinch) the branch/stem seen in the image, the buds closest to the pruning cut will almost immediately begin active growth (within hours). If you don't cut back far enough, only the buds immediately below the pruning cut, potentially leaving you with pretty much what you have except a slightly shorter bare spot.
Also, and very important, because plants age differently than animals, tissues nearest to the root to shoot transition zone maintain their juvenility, which makes them the most vigorous part of the plant. The closer you cut back to that transition zone, the stronger the plant's response will be.
Timing also plays a major part in how enthusiastically the plant will respond. Now is not the time to be doing any hard pruning because the loss of foliage can seriously impact the plant's ability to create energy/ make food (sugar). It would be best if you could hold off until sometime between Memorial day and the summer solstice. The plant will have rebuilt it's energy reserves, making the response both faster and more robust. Fertilizing a month or so before the pruning with a high-nitrogen lawn fertilizer will also contribute to the response if your soil is at all deficient in nitrogen, a nutrient that plays a major part in getting bud growth underway.
If compact/bushy is the goal, leave the growth at the base of the plant. They will develop into new stems which can later be pinched.
@Gina1960 You can cut the plant back as far as you like w/o need for concern the plant might be damaged. Best time to prune is a few weeks after the spring push begins.
Al
