Winter is still the best time to prune woody plants; shrubs and trees

Prune trees in winter

Prune trees in winter

Woody trees and shrubs are best pruned when sap flows slowly during dormancy. As these plants start into active growth, they are more likely to bleed sap and to go through more shock when cut back severely. Minor pruning can be done at any time of year, but winter tree pruning is the best time for the heaviest trimming.  So time is running out!

Young fruit trees should be pruned (and sprayed at this time of year) properly according to the type of tree. Most fruit trees do well trained in a vase shape, so pruning out wood and crossed branches in the middle of the tree is best. This lets light into the center of the tree so the fruits ripen well. Prune cherries, apples and pears with a single tall shoot rather than the vase shape.  In general, cutting about one third of last year’s new growth will help keep the tree from growing lanky yet leave enough wood for flowering and fruiting.  Some fruit trees will set fruit on newly grown wood, but most set on last years’ growth or older wood.  So you want to preserve some old wood and allow the tree to add new wood for the future.  There are many good books and web sites dedicated to fruit tree pruning.  Let it suffice to say that winter is the time of year to get the job done! I do want to underscore that the shaping of your fruit trees in the first few years will set up the health and productivity of those trees for the rest of their lives.

Shade trees are best pruned young as well, so they grow into a healthy, wind-resistant shape.  This means cutting lower branches to encourage taller rather than bushy growth.  If you want to have a trunk you can pass under easily when the tree is mature, you will want to remove a few of those lower branches each year.  Take off no more than three or four branches, ideally while they are still less than 1 inch in diameter.  You can shorten another two or three for next year’s removal.  And if the central stem of the tree starts to branch, it is best to shorten new competitors.  This is called single-heading.  If two main branches are allowed to develop, one is likely to split and break in the wind when the branches get heavy enough.  This can severely injure the tree and will certainly make it less attractive.

If your trees are overgrown and harbor dead branches, call in a tree trimmer. Make sure you have someone who knows and cares about your trees because different trees require different pruning approaches. Sometimes the least expensive tree trimmer doesn’t know this and lops off whatever is convenient, wounding or encouraging the tree to grow out unattractively and leaving it vulnerable to insect attack, or worse, condemning it to death.

Pruning can be a science in itself.  You’re always safe cutting out dead wood.  It’s better to trim less if you aren’t sure.  But don’t neglect those young trees.  Proper pruning when young not only establishes the beauty and health of the tree for the rest of its life, but helps it grow in a form that assures future safety for the people and structures around it.

It’s getting late to prune roses, but you can still squeeze the job in: the roses will simply bloom later in the spring. The pruning of roses depends on how you want your roses to grow. Look up proper pruning methods in a gardening book or the internet for details. Taking the bush down to about a foot tall will encourage long, strong growth in the spring. Cutting back less radically (about a third) will produce shorter stems with a bushier look. You will get more, but smaller flowers. Butterfly bushes (Buddleia) benefit by being cut back severely. Most bushes and shrubs can be shaped now and any decorative grasses that have gone into dormancy for the winter can be cut back low. Ornamental grasses will be sending up green growth by now, so if you haven’t cut out the brown stuff, you’ll want to do it before it gets too difficult to get at.

If you have tender shrubs and trees like Hibiscus, Brugmansia, Citrus and Abutilon, leave them alone for a little while longer if you live where frosts are still possible. Frost in December may have caused some damage to outer branches that can be trimmed back in the spring. (This goes for most perennials and climbers, too.) For now, those cold-burnt branches will form protection for the rest of the plant from winter’s chill (if winter ever returns!). Most of these plants need protection in our area even though this has been another mild-temperature winter like last year.

Know that just because it has not been a cold winter in Southern California, we can still get some frosty nights in in-land areas, so make sure your most delicate plants are still sheltered beneath an overhang or are placed close to the house. When frost hits, you want the soil to be moist enough that the roots don’t freeze. But don’t keep the soil wet because wet + cold = bad news for winter survival.  The hardier plants in the ground should have their protective mulch cozy around their roots, and a more delicate plant that cannot be moved will benefit from both mulch and a loose-fitting fabric cover at nighttime.

Apart from pruning and clipping woody plants, you may also want to take some time to hoe the surface of areas where weeds are germinating. With the generous rain we’ve received this winter, weed seedlings are sprouting all over the place. If you scrape them down early, they are easy to clean up. Waiting until their roots grip into the soil will make the job much harden in a month or two.