Pruning season begins with new year

By Staff
January 14, 2004
For all the mad hackers out there, get away from the computers and sharpen up those pruning shears. January is smack dab in the middle of the dormant season, and is the prime time to begin reshaping and renewal of prized landscape trees or shrubs.
A wide range of plants can benefit from late winter pruning, especially broadleaf evergreen foundation shrubs like holly, cleyera, boxwood, red tip photinia, nandina and euonymus. Plants of this type normally have one main growth spurt that starts in early spring, so it is best to whack them back just ahead of this growth cycle for maximum results.
Before you go to hacking, remember that spring blooming evergreens such as azalea and Chinese witch hazel (i.e. "Burgundy" Loropetalum) will be flowering in just a couple of months, so their pruning can wait until right after the bloom period.
Summer flowering plants that bloom after May (crape myrtles, roses, althea, gardenia, vitex) will flower on brand new "wood" that emerges this growing season, so pruning them now is no problem.
Anytime between mid-January and the end of February is good pruning time for the summer bloomers, and many gardeners may wonder why pruning is not recommended during late summer or fall.
Pruning stimulates new growth soon after the plant stems are cut, and young tender shoots are very prone to freezing temperatures.
Gardeners with the itchy trigger fingers who pruned between Labor Day and Halloween are likely to have shrubs with winter freeze damage by now. Plants with thin woody bark are particularly prone to bark splitting (fruit trees, privet, azalea) as plant sap turns to ice on frosty nights and then thaws quickly the next day. Injury may extend into the root zone and kill entire plants.
The goal with pruning is to first remove dead or diseased growth, then focus on reshaping and reducing plants to a functional size. To keep plants on a normal flower or fruiting cycle, only about one-third of the total height or width is pruned away at any one time.
Severe renewal pruning to the ground can be done on tough established shrubs like holly and camellia, but is not necessary in most cases. Severe pruning and removal of large limbs should be done before March while the sap is still down in the root systems. Pruning paint or other treatment of the cuts is not needed.
When pruning evergreen hedges, remember that sunlight must continue to reach the base of the shrubs to maintain thick foliage all the way to the ground.
To prevent shading and thinning of lower branches, prune the shape of the hedges in a triangular or trapezoidal form, where the base is left wider than the top to capture sunlight.
For fruit trees such as fig or peach, wait about another month before pruning if possible. Delaying pruning until around the first of March helps hold the plants in dormancy longer, and this can be an advantage for plants that are susceptible to late spring freezes. March is also a great time to fertilize any of the plants you have pruned this winter.
A couple of other pruning tips are to always use sharp shears, and to prune stems at a 45-degree angle to speed healing. Pay close attention to where buds are located before making pruning cuts, because the direction of the top bud left on the pruned stem will be the same direction the new branch tries to point.
Be aware that vigorous growers such as crape myrtle and loropetalum can grow back six or eight feet in a single summer, so cutting them back properly the first time will prevent excessive pruning later in the growing season.
For more info on pruning and other winter gardening chores, visit the MSU Extension Web site at www.msucarescom.