One of the most colorful springtime flowering shrubs is forsythia. Profusely covered with bright yellow flowers in early spring, these woody plants are popular and easy to grow. They come in many forms, including dwarf and standard varieties. But like any plant, proper care will produce better results when they bloom.
If you are planting forsythia, choose a site in full sun if possible. Forsythia will tolerate most soils, but avoid heavy, poorly-drained soils. Be sure to allow plenty of room for future growth. A spacing of 5 to 7 feet apart is recommended, and at a minimum of 3 to 4 feet from structures. After planting, a little mulch is good for moisture conservation. Don't overwater, but make sure they don't dry out either.
As the plant grows through the years, you will soon see that forsythia needs annual pruning to keep it attractive. The critical point to remember about forsythia is that it forms its flower buds on the new summer's growth. The following spring, those buds will flower.
Because of its flowering habit, timing your pruning is critical. If you wait until fall or winter to prune, like you do with many species, you will be removing flower buds and will have a less attractive bloom, with fewer flowers. The best time to prune is right after the forsythia has finished blooming, in the spring. That way, the new growth will start forming those all-important flower buds, while you have controlled the shape and size of the plant.
When you are pruning, keep an eye out for old, weak, or diseased wood. This should be removed, if possible. Branches which are particularly bad should be cut back to the ground. If the plant is otherwise healthy, this will produce new, vigorous growth.
If you enjoy propagating plants, you can use softwood cuttings of forsythia to produce new plants. Softwood cuttings are taken in May through late June from current season's (new) growth. The cuttings are taken when the wood is flexible, but mature enough to snap if bent sharply.
New cuttings should be cut with a sharp knife. They should be from 4 to 6 inches long. Take your cuttings on the plant just below the point where leaves are attached to the stem (a node). Before placing in the rooting media, it helps to use a rooting compound to encourage root growth.
Rooting media should be well drained. A good choice is coarse sand, perlite, or vermiculite. Make a hole with your finger about two inches deep, and place the cutting in it, taking care to not brush off the rooting compound. Firm up the media to the cutting, and water well. Be sure to check often to make sure the media does not dry out, since the cutting does not have any roots yet, and will need plenty of water. Roots should develop within 6 to 8 weeks. After sufficient roots have developed, harden them off before transplanting by decreasing the water supply. Don't let them dry out, but stress them a little.
After hardening them off, place them into individual pots using a good potting mix. In a few weeks, they will be ready to transplant outdoors. Some people prefer to plant them in a temporary nursery setting before placing them in their permanent location.