Thawt it would come: Late winter pruning windows

Perhaps an arborist has already told you how much we complicate their job by planting "Please don't trample my ____________'s" all around trees' bases. Winter pruning spares the garden at a tree's foot.

Perhaps an arborist has already told you how much we complicate their job by planting "Please don't trample my ____________'s" all around trees' bases. Winter pruning spares the garden at a tree's foot.

It's a thaw if

...for three or more days the daytime temperatures are above freezing and nights stay above 25F.

If it's dry, too, then it's perfect pruning weather.

Why?

Frozen ground will support your weight without damage to the soil. Not worried about that? You must not have any planted around trees as in the photo, unlike most of us!

More reasons to capitalize on a thaw

48 hours of moderate temperature is enough for stub wood suddenly exposed to the air to harden against cell damage.

Maples, birches and beeches that tend to ooze sap when pruned may remain dry. Although this "bleeding" is not a problem for the tree it does upset gardeners and gunk up pruning tools.

A deciduous tree's structure is apparent when it's leafless. It's easy to decide what to cut.

While you're out, you can cut back any shrubs you planned to prune before budbreak.

On our pruning hit list:

  • A spruce we are keeping small.
  • Several old, worn lilacs, honeysuckles and weigela. We'll lose a year's bloom on each cane we remove, or all the bloom if we opt for cutting them to the ground before budbreak. However, the rejuvenated new wood and clean lines will be worth any lost-flower cost.
  • Many summer blooming species that remain smaller and less cluttered than they would otherwise be.
    Dwarf spirea, rose of sharon, potentilla, beautyberry (Callicarpa), panicle hydrangeas (H. paniculata varieties such as 'Limelight' and 'Peegee') and blue mist (Caryopteris) are in this category.
    We cut them to the ground.
    We could prune them this way only every 2 or 3 years but most are on our list pretty much every year.
  • Shrubs we grow for stem color rather than flower, such as redtwig dogwood, yellowtwig dogwood, Japanese Kerria, and blue willow (Salix purpurea).
    We cut some or all the stems to the ground.
  • We cut so you can walk on it* when we cut to the ground.

*Thus shrub pruning during a thaw is problematic when the ground is covered in deep snow. We don't relish the extra work of clearing the snow around the shrub base, yet we want to cut shrubs to the ground. We do not want an ever-increasing clutter of stem bases to work with, but clean new stems from the ground level.

Because it is important to avoid wet tools and wet wood, we end up clearing snow as one operation, then putting on dry gloves and sometimes changing clothing, too.

There is more about pruning during thaws

...in these articles already posted on GardenAtoZ.org:

Winter Clips

Pruning Panicle Hydrangea in Winter

Thaw a Chance to Prune (Japanese maple)

Wattle Red Twig

Cut Harder in Spring

Rejuvenating an old lilac

It's easiest to see what to do at the base of a lilac during winter.

We regularly cut 2 or 3 large canes out of a lilac to keep the overall height within bounds. That also keeps the maximum cane diameter to less than lilac borers need to thrive, so the lilacs do not become weak from borer activity.

We regularly cut 2 or 3 large canes out of a lilac to keep the overall height within bounds. That also keeps the maximum cane diameter to less than lilac borers need to thrive, so the lilacs do not become weak from borer activity.

Here, 8 feet is a good height and we have removed 2 canes.

Here, 8 feet is a good height and we have removed 2 canes.

Since it was only 2 years ago that we took charge of this lilac and removed a great deal of large-diameter, 12' trunks, there are many suckers that grew in response.

Since it was only 2 years ago that we took charge of this lilac and removed a great deal of large-diameter, 12' trunks, there are many suckers that grew in response.

We have now thinned those to leave straight, strong stems. These will grow for about 5 more years and bloom 3 or 4 times before becoming candidates for removal.

We have now thinned those to leave straight, strong stems. These will grow for about 5 more years and bloom 3 or 4 times before becoming candidates for removal.

We could remove more canes.  We'll wait in this case until after the shrub blooms. Its crop of new canes are not yet blooming age so we keep a few of the older canes for the sake of more flowers.

Return to pruning hit list.

"A" would be the first choice, as it is growing out at a low angle and suckering. Either of the "B" canes can go and "C" is expendable too because it is growing in such shade and close competition that it cannot be productive of flowers.

"A" would be the first choice, as it is growing out at a low angle and suckering. Either of the "B" canes can go and "C" is expendable too because it is growing in such shade and close competition that it cannot be productive of flowers.

Honeysuckles often become overgrown tangles of deadwood

Shrubs are more resilient than most gardeners imagine.

Here is an account of a 45 year old honeysuckle that had not been pruned in many years. It had to be cut hard because it was blocking motorists' view of children approaching along the shoulder of the road.

It was not easy to cut out dozens of canes, some 2" in diameter and all crowded. We would rather have worked in winter and sweated less. But September was when the neighbors moved away who were half the reason this property line shrub had become a monster. With no new owner yet, we had no need to consult.

We could have executed Steven's "one cut pruning method."

We could have executed Steven's "one cut pruning method."

We opted instead to leave some of the youngest straightest canes and a bit of the foliage.

We opted instead to leave some of the youngest straightest canes and a bit of the foliage.

The next year the shrub was a dense mass of new canes and we smoothed the outline by cutting out those left intact during the first pruning.

The next year the shrub was a dense mass of new canes and we smoothed the outline by cutting out those left intact during the first pruning.

After two years. During that second year of renewed growth it resumed blooming. The following winter we thinned the multitude of canes that resulted from the first cut.

After two years. During that second year of renewed growth it resumed blooming. The following winter we thinned the multitude of canes that resulted from the first cut.

Return to pruning hit list.