Keep ‘Em on the Up and Up Protecting Upright Evergreens from Snow-load Breakage.

By Curtis Utley, CSU Extension Agent, Jefferson County

Upright junipers. The center specimen has a co-dominant leader

Upright or fastigate evergreens are a common and attractive feature of many home landscapes often used as screen plantings or focal points in narrow planting beds. However, In Colorado, or any community frankly that experiences heavy snow fall in the winter, these narrow specimens can be damaged, disfigured or down-right destroyed by heavy snows.  Why does this occur?

Snow-load impacted Arborvitaes

Narrow tree forms succumb to snow load breakage because the side branches are poorly attached. The strongest branch attachment forms a 90 degree angle between branch and trunk (think of any native spruce or fir). When branches are attached more acutely there is

Right-angle branching

less trunk material to hold the branch into its socket. The likelihood of included bark forming between the trunk and a branch increases if a branch immediately ascends from the tree’s trunk. The other reason Fastigate cultivars often break in snow load events is our fault in how the trees are pruned and managed. Most narrow cultivars are sheared to keep their appearance balanced and tidy. If the terminal branchlette is clipped and apical dominance is removed, aggressive, competing side branches will try to grow up and become the leader.

Strong central leader

If these competing side branches are maintained they will grow into co-dominate leaders that will have included bark in the future and may break in future snowstorms.

Co-dominant leaders failing after heavy snow load

So what should you do to protect your fastigate trees in the winter?

Wrap them with Ag fleece.

Ag Fleece protects shrubs from snow-load and desiccation

1. Wrap them with straps

Wide strap wrapped around a Woodward juniper

Light cord or Christmas lights can prevent snow load breakage 

2. Wrap them with Christmas lights or light cord

3. Stake them when small and tie them loosely to the stakes

How to Help Storm Damaged Trees

Posted by Carol O'Meara, CSU Extension Boulder County

  Driving to work this morning revealed the impact of this heavy, wet snowstorm.  Young trees are bending under the weight of a foot or more of the white stuff.  Larger, older trees remain upright - thanks to stout trunks – but are lowering their branches.

 And some trees are losing limbs while others rocked completely out of the ground.  If you spot a damaged or downed tree on public property, notify your city forester’s office so they can put it on the schedule for maintenance.

NEVER APPROACH A DOWNED LIMB ON A POWER LINE.

Caring for trees on private property is the responsibility of the owner but if your trees are overloaded from the snow there’s no need to panic.  Some people are suggesting you grab the branch or tree and shake it, but that might add to the stress on the wood.  A better approach is to use a broom to very carefully knock off snow.  Use the broom in an upward motion to knock the snow from the branch instead of sweeping down onto the limb and adding more weight.

 If your tree has broken branches, the best thing you can do is to get the wound as neat and clean as possible.  Take a sharp knife and remove all the jagged edges of bark around the tear.  Don’t bother with wound paint – the tree will heal the wound.

 If possible, trim branches to leave a clean cut, making sure you follow the three steps for proper pruning (which prevent bark tears):

1.  Twelve inches away from trunk or from where you want the prune to be, make your first cut on the underside of the branch, sawing upwards through one-third of the branch.

2.  One-inch outward from the undercut, saw downwards through branch.  At the point of no return, the weight of the branch will snap the limb, but the undercut will stop bark tearing of the tree. 

 3.  Make your last cut just outside the branch collar, the spot where branch and trunk join.  Often, you can see a slight swelling at this point. 

 Find a diagram of this pruning method at PlantTalk Colorado.

 If you’re not sure if your tree is a goner, contact an arborist to assess it.  Those with less damage should be cleaned up, then have close attention to care over the summer.  Water them if we’re dry, and keep them healthy.

 

 

 

 

Knock it Off: Preventing Snow Damage to Trees

Posted by: Alison O'Connor, Larimer County

Mark your calendars, folks! It's Mother's Day, May 11, and the snow is coming down fast and furious. By the time it's all said and done, up to 9-12" of wet, heavy snow (yea moisture!) is expected, but for our woody plants that have leafed out, this means bad news and possible damage.

So take precaution now and go and gently knock the snow off the trees and shrubs (and perennials) that have been coated. The leaves capture a lot more snow per surface area than branches, and this is what makes branches droop and break. Evergreens also need attention.

Shaking off the snow is one of the best things you can do to prevent damage...and you may have to repeat this a few times until the snow stops. But be gentle--don't vigorously shake, just do some light taps or brushing.

The mighty broom handle!

The "weepy" star magnolia outside the hort building.

Tap, tap, tap.

Free from snow and ice (the blue spruce is another project).

By the way, the turf specialist said your lawn is fine.