Rose of Sharon Blue Satin PP#12,680

You needn't cut down annuals when they finish for the season. You can just yank them out. Annuals live only one year. Leaving their roots will do no good.

Perennials usually don’t have a very long bloom period. They often will benefit from a trim in midseason, either to keep them at a manageable height – think perennial prairie sunflowers (Helianthus maximilianii) and chrysanthemums – or to stimulate newer, healthier looking leaves – think leaf miners in columbine (aquilegia).

Sometimes this tidying will also bring about another session of fall flowers. When fall turns to winter cold, you can cut the dead leaves and stems to the ground and mulch them. Supplying this blanket will give perennials a better chance of survival during their winter sleep.

Shrubs and trees are another matter altogether. Pruning is done in different seasons depending on the bloom time of the prunee', or the results you, the pruner, wish to accomplish.

Although many gardeners think they prune to contain growth or keep a plant small, pruning usually stimulates a plant to expand. Twiggy growth results from pruning while a plant is still growing. When we prune a bush, it becomes bushier.

This is the very reason you should not prune a shrub in the fall. As the air is ready to turn from nice to ice, any new growth stimulated at this time of year is susceptible to a quick freeze. Not only can it kill the young growth, but also the injury can travel down the stem, opening up whole areas of the shrub to winterkill or rot or insect attack. Wait until the shrub or tree is dormant before you begin your attack.

A quick rule of thumb: Prune in the late winter or early spring before the new growth starts, any summer flowering shrubs or trees that bloom after June 1. These bloomers usually blossom on new wood, so stimulating new growth promotes more flowers.

Some bushes that should be pruned in the late winter or early spring are Beautyberry (Callicarpa), Floribunda Roses, Japanese Barberry (Berberis thunbergii) Japanese Spirea (Spiraea japonica), Rose-of-Sharon (Hibiscus syriacus), Summer Sweet (Clethra alnifolia), Anthony Waterer Spirea (Spiraea x bumalda ‘Anthony Waterer’).

Trees that should be pruned before they leaf out are Chastetree (Vitex), Sourwood (Oxydendrum arboreum), Goldenrain Tree (Koelreuteria spp.), and Mimosa (Albizia julibrissin).

Prune spring flowering shrubs or trees, those that blossom before June 1, after they finish flowering, in late spring or early summer. Since they set their buds on growth from the previous summer, if you prune them in the late winter or early spring, you cut off the flower buds waiting to burst in the new year.

Hydrangea quercifolia 'Pee Wee'

Trees that should be pruned after they have spent their flowers include Crabapple (Malus spp.), Bradford Pear (Pyrus calleryana ‘Bradford’), Dogwood (Cornus spp.), Flowering Cherry (Prunus serrulata), Lilac (Syringa vulgaris); Redbud (Cercis spp.), White Fringetree (Chionanthus virginicus), Saucer Magnolia (Magnolia x soulengeana), and Star Magnolia (Magnolia stellata).

You can cut out dead wood at any time. Some trees have a tendency to bleed. This oozing sap probably isn’t enough to harm the tree, but it does look like you’ve been an abusive gardener. Wait to prune maple, birch, beech, elm, willow, or plum trees after their leaves have totally matured. They will still bleed sap, but not enough to cause your neighbors concern.

If you must make major cuts on trees, like removing limbs, do this during their dormancy even if they are spring flowering. Think of a dormant tree as under a kind of sedation. The tree will recover quicker and you will be able to see the structure of the tree without leaves to interfere with your sight or your work.

Wait to prune hollies and other winter berried bushes and trees until late winter, before they flower in the spring. This preserves their berries for the winter and for the birds.

You can prune any tree or shrub during its dormancy. Just remember that you might be sacrificing the coming year’s flowers or berries or you might have a bleeder. The plants will recover and you will have blossoms aplenty in another year, that is if you don’t make unkind cuts during their formative seasons.

---Posted by Coach Anne November 5, 2008---