TREES AND CONSTRUCTION PART TWO: How to treat damaged trees

In my last article, I discussed how construction negatively affects trees: by smothering roots from increasing grade; soil compaction from heavy traffic; root damage from digging; exposure to elements when select cutting; and damage to truck/crown from passing machines. Here are some pointers if a mishap does happen. 

ROOT CARE:

• If you change the grade of soil near a tree, and compensate with a well or another type of barrier, monitor the irrigation and drainage. There should be a balance of how much water is retained and released. Optimal watering is a slow and deep soak over the entire root zone (1-3 times greater than height of tree).
• Mulching helps with moisture control and prevents further soil compaction. Read the article about mulching for detailed instructions.
• If soil compaction is an issue, soil aeration may be necessary. This can be done with a high pressure air-excavation device, or by hand, taking care to not damage roots close to the surface.
• Fertilizer is not recommended following damage from construction. Quick-release fertilizers contain salts that draw moisture out of roots into the soil, and added nitrogen encourages top growth at the expense of root growth.

TRUNK/CANOPY CARE:

• Remove lose bark with a sharp knife, taking care not to touch living tissue
• Any broken, torn, and diseased limbs should be properly pruned. DO NOT reduce canopy to compensate for root loss as this may stress the tree even more.
• Cabling and bracing may be an option, but is not a recommended do-it-yourself project. Talk to an expert.
• Please keep in mind that though wound dressings were once thought to be helpful, there is no scientific evidence to suggest that they provide any positive results.

TREES AND CONSTRUCTION PART ONE

Are you building a new home or doing renovations? Are you doing some serious landscaping or building a new driveway? Considering how valuable trees are to homeowners (increasing property value, mitigating costs of heating/cooling, and improving mental health), most people want to protect their trees. But even if you don’t care if you lose a tree or two during construction, a homeowner should definitely be aware of the consequences of construction. Think of what happens if someone unknowingly harms a tree that is growing directly next to a new building site: the tree begins to die, close to a unit, and becomes a significant liability for the homeowner.

Trees are seriously affected by man and machine impacts during construction. Obvious physical damage to the trunk and crown of the tree can be caused by passing machines and materials. The “silent” killers happen when there is damage to the roots. A root system is NOT a mirror image of the aboveground tree--it is 1 to 3 times greater, horizontally, than the height of the tree!  Adding soil or increasing the grade, even just a few inches, effectively “smothers” the special water- and mineral-absorbing roots that are growing close to the surface. Root damage is also caused by heavy foot traffic or heavy machinery compacting the soil, limiting water penetration and decreasing the oxygen needed for root survival. Digging and trenching can damage or cut roots, making it difficult for the tree to stay upright in storms. And if you have to remove a few trees in a cluster, be aware that new exposure to the elements will affect the remaining trees, including sunscald and limb breakage from wind.

You can certainly protect your trees and property by planning prior to construction--though not all trees may be feasibly saved.  You can consult with an arborist to get advice on which trees are best suited for certain locations depending on the health and structural integrity of a tree, and its species, age, and size. You can talk to your contractor to make sure all workers are aware of your needs and desires. Setting up sturdy perimeters around vulnerable and prized trees is a great way to protect them: set a fence ONE foot from the trunk for EVERY INCH of the tree’s diameter. Think ahead and educate yourself so that you make the best choices for your trees and for your property. Planning can save you a big surprise headache! 

WOODPECKERS

What's the relationship between woodpeckers and trees? Does the bird's drilling hurt or help the tree?

We have fourteen woodpecker species in Canada. Some common species in our area are downy and hairy, and the largest, pileated woodpeckers (Picoides pubescens, Picoides villosus, and Dryocopus pileatus), as well as yellow-bellied sapsuckers (Sphyrapicus varius) and northern flickers (Colaptes auratus).

First of all, most woodpeckers nest in already dead cavities of trees, or in standing dead wood. (Some species actually prefer man-made birdhouses!) Insect-eating species, like our most common downy woodpecker, will feed in bark crevices. The woodpeckers who bore holes to feed are harvesting from a tree that already has an insect presence. This is just nature doing its thing.

If it's spring and you hear "drumming" on parts of your house, don't worry--it's most likely a territorial male sending out signals in the nesting season. He's not actually boring holes in your house. (Though, there are instances where peckers will damage a home while foraging or nesting, so look for the holes as evidence of a real problem)

Sapsuckers are a different story. As the name suggests, they drill holes in patterns to harvest sap from the tree. They have a strong preference for white birch, which has a high sugar content. Though sapsuckers will return to the same tree and holes to feed, the systematic drilling of patterned holes can eventually girdle a tree--although, research has shown that sapsuckers can detect "stress" in a tree, and actually prefer trees that are already in decline. (Stressed trees produce more sap as a defense mechanism, so it makes sense that the sapsuckers prefer this.) They are migratory so they only hang around our area in the summer.

A word to homeowners with fruit trees: though they prefer birch, sapsuckers also like to drill fruit trees. You can deter sapsuckers by wrapping vulnerable tree trunks, but if you notice the systematic drilling pattern of a sapsucker on only one tree, you might as well leave it. If deterred, the sapsucker might simply choose a nearby tree to begin drilling again. When it comes down to it, woodpeckers are following the natural order, and seem to choose sustainable lifestyles (i.e., nesting in dead wood, and feeding from already stressed trees). Enjoy the birds!

PLANTING WILLOWS FROM CUTTINGS

Do you have a willow in decline? Don't worry: Willows and poplars can be easily planted from cuttings. You can enjoy the life of your majestic and mature tree while you watch a new tree grow. Here are some tips for successful planting:

• Cuttings should be collected from HEALTHY trees in spring just before bud break; put cuttings in sealed plastic bags and put in cold storage (fridge, basement) at 5 degrees for a week or so until ground thaws.
• Harvest from the previous season's growth, the last 25 cms of the branches where at least five buds are showing
• You can plant directly where you want the new tree to grow, but the best way is to treat the cutting to a garden plot for the first year of its life
• Cuttings will take root quickly if you soak in water for THREE days before planting (but not more than three--you want it to show roots in soil, not the water)
• Keep soil loose and plant vertically to the full depth of the cutting with the buds facing upward; pack soil firmly and water immediately
• Plant a few cuttings to increase your odds (keep them at least six inches apart to prevent their roots from tangling)
• Water often when soil is dry, and weed to give the cutting the best chance of survival. Don't waterlog the soil.
• If you transplant to permanent location, do so after one growing season; cuttings will produce lots of roots in first season and will be difficult to move after a year
• Transplant in early spring and mulch/water for best survival rates

EMERALD ASH BORER

I went to a panel discussion in Kanata on March 27, 2013, to discuss the Ottawa’s approach to the EAB problem. Ash trees are dying at a paralysing rate; the pest has already killed 50 to 100 million trees in North America since EAB was discovered in the Detroit-Windsor area in 2002. From that point, EAB has been spreading in all directions, infesting 65,000 hectares in Ontario and recently hitting Quebec and 17 states. In the United States, three types of parasitic wasps were imported from Asia (one species attacks the larvae and the other two attack the eggs).  It hasn’t yet been determined if their numbers will increase to the point of an effective controlling measure, but all three species successfully over wintered.  The Canadian Forest Service and Ministry of Natural Resources are considering following suit to release wasps in Canada. In Canada, the Canadian Food Inspection Agency is in charge of biological control measures, but (as expected) processes are very slow going and it is part of a long-term plan. The beetle was discovered in 2008 in Ottawa, and the city council has banded together to form a management program. The Council’s EAB strategy consists of five steps:

1. Regulation of wood movement/disposal

2. Tree removal

3. Selective tree injection

4. Proactive tree planting

5. Public awareness and outreach

IDENTIFICATION: The emerald ash is a metallic green wood-boring beetle (1/2” long 1/8” wide) native to China and Eastern Asia; the larvae are white and flat and can grow up to 1”. The beetle attacks all North American true ash trees (of the genus Fraxinus); it does not invade other tree species. The beetle lays eggs beneath the bark and feeds on the leaves; the larvae feed on the wood beneath the bark leaving “s” shaped galleries.  Upon infestation, the tree’s ability to transport/nutrients is choked and the tree starves.

How to identify an infected tree:

dieback at the crown and loss of green in leaves at the top of tree

fewer and smaller leaves

epicormic sprouts (they  look like small shoots/suckers in the lower regions of the tree)

Because the bug is hidden beneath the bark, infested wood is often moved without people knowing and this ultimately spreads the pest. Please don’t move firewood or anything you suspect is ash. 

Bioforest Technologies Inc are the only government-endorsed injection provider. The product is called TreeAzin. It is a biologically based insecticide made from the oil of neem trees and it’s required biannually. The injection method is fairly invasive because you must drill multiple holes at the base of the tree to administer pesticide, and it is a short-term plan until scientist develop an effective response. The pesticide, after it is injection, is transported through the vascular system and into the leaves; it targets female beetle adults eating the leaves, and sterilizes the female. The pesticide also disrupts normal molting in the larvae and kills the larvae this way. Injections are a preventative technique; if the tree can’t transport nutrients due to the activity of the beetle, it isn’t effective as the insecticide cannot be transported throughout the tree after injection. Planting suitable replacement species is a very good proactive measure if you have many ash trees on your property. After infestation, the ash tree is expected to live between 2-5 years; that is a pretty good chunk of time for a new tree to grow.

Public awareness is the best advocacy step. People should know how to identify an ash tree (especially so it isn’t accidentally moved), know that the trees are at risk, and think about the best steps to manage existing ash trees. Part two of the discussion will follow my conversations with local authorities, as provincial and municipal efforts vary depending on areas. I hope to lay out the ash management plan for the Gatineau Hills area, but in the meantime residents should consider taking a walk on their property to see if they can spot an ash tree. Here is a tree identification guide to help you out:

 http://treedoctor.anr.msu.edu/ash/ashtree_id.html

PROTECTING TREES AND PLANTS FROM DEER

The best method to protect your garden is a fence. It’s expensive and time consuming, but it’s the only way to guarantee that deer won’t eat up all of your hard work. Plant pungent smelling perennials like garlic, chives, and lavender to mask the appealing aromas of nearby annuals. (Here’s some more deer-resistant plants: http://njaes.rutgers.edu/deerresistance/). Use a scarecrow.

Back in the day we used to use mothballs (before environmental concerns were raised). A couple of new tricks include bundling up hair (dog, cat, even human) in bags and hanging it up; rubbing highly scented soap on the bark of vulnerable trees, or hanging bags of soap in branches; spraying with a hot-pepper spray -- the competing smells confuse the deer. There are also some products on the market including Deer Away and Deer Off.

Here are some tips generated from local residents:

1) Plantskyd-liquid deer blood. It has proved effective on my hostas and fruit trees. Do not follow instructions on the container to spray it on your plants and trees. Rather, put the liquid in a yogurt container and paint it on the bark and branches of fruit trees with a brush, or else brush the liquid on stakes and place them in the ground around valuable plants. Use a container that has a secure fitting lid for storage. It stinks, so keep it somewhere you do not have to smell it. Also it cannot freeze, so must be stored inside in cold weather. It will last, even in rain, for a few weeks.

2) Creating deer lines. I use fly fishing line to string a “fence” at chest height around a tricky spot across a deer run behind my garden. Deer walk into it and quickly shy away as they touch something they cannot see--it’s a defense mechanism. Fishing line is cheaper than sprays. I use fly line because it is stronger. You do need to remember where your lines are strung; you could even hang prayer flags along the same spot to define (with deer line below). The key is, you are building a “fence” so unless you enclose the space, eventually the deer will figure it out. 

3) Lighting: since deer like to feed at dusk and dawn, motion sensitive floodlights/outdoor lights will scare deer away. Similarly, motion-sensitive lawn sprinklers will also send them running.

TREE PRUNING

Many people have asked me to explain exactly what pruning is. Since we’ve just celebrated earth day, it’s important to speak up on a tree’s behalf.

Pruning is cutting branches or parts of trees or for improving the shape or growth of trees (using shears, pruning saws, chainsaws). It’s the most common tree maintenance procedure. Usually, trees are pruned as a preventative or corrective measure to remove dead branches, crowded or rubbing limbs, to eliminate hazards, and to increase light and air penetration. No branch should be removed without any reason--each cut to a tree has the potential to change the growth. 

Trees in national parks don’t usually require human intervention because they are natural spaces and should be left to their own devices. But when humans and trees share space, it’s a different dynamic. Small trees will eventually grow to be big trees, and sometimes they grow in places that are inconvenient or even dangerous (over buildings and wires). It’s best to prune trees when they are young; they’ll require less corrective pruning as they mature. Also, small cuts do less damage than large cuts--if you proactively maintain young trees with pruning, you’ll reduce the need for more drastic pruning later.

Here's a link to proper pruning techniques

If we think ahead and care for trees properly, we can avoid instances where hazardous trees need to be removed completely.

USING VEGETABLE OIL IN CHAINSAWS

I’ve had quite a lot of people ask me what I mean by eco-friendly tree care, including “no chain oil”. Chainsaws require a lubricating agent in order to run the chain and bar, and generic chain oil is petroleum based. This means that when a chainsaw is running, virtually all of the oil in the reservoir ends up on the ground. And the oil mist ends up in the user’s lungs.

You can switch from petroleum-based products to common vegetable oil (which is cheaper, too). The downfall is that if you leave vegetable oil out in extreme cold, it will freeze. I solve this problem by keeping my big container of oil inside in the winter, and a smaller bottle to take along to jobs, which gets used up quickly. (Stihl also makes a biodegradable chain oil, but it’s not always available in remote locations--ask your local retailer.)

Europe (and California) is leagues ahead of us in using vegetable-based oils as a common, regulated practice. In Austria, for example, petroleum-based chainsaw oils are totally banned. 

Here’s a very useful article which lays out tips for making the switch, but really, it’s easy! 

http://eartheasy.com/blog/2010/11/using-vegetable-oil-to-replace-chainsaw-oil/