Keeping shrubs and small trees healthy is vital not only to their appearance, but also their ability to fight disease, insect infestations, and extreme weather. Plant pruning encourages new growth and blooms and is necessary for many species of shrubs and small trees. If left unpruned, many plants become woody and do not produce enough new wood to support blooming.
However, when it comes to plant pruning, many questions arise as to what is old wood and what is new wood? Distinguishing between old and new wood is crucial in understanding the correct wood pruning methods for your plants.
What is Old Wood?
Spring flowering shrubs such as forsythia bloom on last year’s stems, which are known as old wood. The best time to prune these types of plants is right after they bloom. Flower buds will form during the summer and fall in preparation for spring blooms.
What is New Wood?
Stems that develop during the present season are known as new wood. Many hydrangeas and summer blooming spirea bloom on new growth. Trim new wood bloomers in late winter or early spring before blooming to encourage growth.
Distinguishing Between Old and New Wood
Most plants develop what is known as a vegetative bud at the end of a year’s stem growth. The expansion of the bud the following spring leaves a noticeable scar. The scar is the place where old growth ends and new growth begins. Many times there is also a slight difference in the stem color of old and new wood.
Wood Pruning Methods on Old Wood Bloomers
Prune old wood bloomers to thin and control size. All dead or crossing stems should be cut as close to the ground as possible.
Since buds will form on old wood, it is important to remember that the more wood that is removed, the less prolific the bloom will be.
Also, be sure to sterilize your pruning shears before cutting.
Wood Pruning Methods on New Wood Bloomers
Plants that bloom on new wood will handle severe pruning, if necessary, in their dormant season.
Most new wood bloomers need to be shaped and thinned, just like old wood bloomers. Be sure to cut back any dead or damaged limbs or any that cross.
As always use clean and sharp pruning shears.