Tree Fertilization

The topic of tree fertilization can be a controversial one. I personally have been on both sides of the fence on this debate which tends to have two primary views. One view is , “Trees do well in the woods and fertilization in your yard isn't needed”. The other view is that, “Trees in their natural environment recycle nutrients and your yard the soils and nutrient recycling are far from ideal”. The first view is one that I held before I spent many years studying trees and their responses to supplemental fertilization. I have developed an understanding for the second position after years of careful observation.

Your yard is a harsh place for trees, the soil has been compacted and modified to such an extent that it no longer bears much resemblance to the loamy duff of the forest floor. Forests are harsh environments, but they are places that trees are uniquely adapted to survive and thrive in. Trees exist in communities and grouping that balance nutrient requirements. Unseen battles for scarce nutrients take place in the forest and result in the forest you are looking at. The trees in your yard certainly would not exist as a community naturally in the woods. I no longer think fertilization is “ Snake Oil”. When correctly prescribed, formulated and correctly applied it is one of the most beneficial applications you can make to your trees.

The results of fertilization can only be seen over time in the growth and development of your landscape trees. Any gardener knows that to keep a plant alive you must water and fertilize it as needed and on a regular basis. If you don't they simply struggle and fade away. The basic N-P-K of fertilizer, nitrogen, phosphorous and potassium, come in a variety of formulations and forms. For trees it is important to have a substantial proportion of the nitrogen in a slow release form that is available to the tree on an extended basis.

There are a variety of ways to apply tree fertilization, broadcasting on the surface, drilling and placing granules into the soil, tree spikes, low pressure high volume hose end feeders, and high pressure liquid injection systems. Each has its advantages and disadvantages, having used all of them over the years I do recommend high pressure liquid injection as my method of choice. This method has the advantage of being able to quickly and accurately, both important considerations, deliver the correct blended fertilizer and soil amendments to the root zone. As we have discussed many times in the past most tree roots are in the upper 12 inches of the soil where oxygen and water are available. Soil fertility, micro nutrients,soil pH and root stimulation are only a few of the areas that can be addressed using the correctly formulated soil injection. The important issues of formulation, timing and proper application can be prescribed by an ISA Certified Arborist. If you want your trees to thrive and prosper, contact your ISA Certified Arborist.

The Depths of Planting

Root Flare on Tree Planted At Right Depth

This time of year will always find me answering questions at plant sales or speaking with students about the importance of planting trees. Unfortunately this year an unseasonal cold prevented me from speaking at either. I did manage to attend and was able to confirm the old saying that “ you have two ears and one mouth so listen twice as often as you speak”. While my voice was out of commission I was able to stand back take a few pictures and listen to one of my fellow arborists speaking with a group of 4 and 5 year olds. He, being unprepared due to my sudden laryngitis , showed true mastery in arboriculture by improvising a great presentation on trees, how important and present they are in our lives. Halfway through I croaked “ Whats in the bag?” and he pulled a small white spruce plug out of the paper bag he was holding. The children were ecstatic and without missing a beat he held the tree up side down and asked “ Do we plant a tree like this” to a gang shout reply of “ No” they all replied, flipping the tree. “ How about like this?”,the tree was now right side up and all agreed that “Green on Top” was the way to plant. So how do we go from this simple consensus to over half the trees in the average landscape being planted to deep?

The simple truth is if I you walked out your door and found a planted tree it would more than likely be planted too deep. At the mall,shopping center, park or many of my clients properties there are no shortage of these buried alive trees.

Trees grown in nature from seed are rarely planted to deep. Flooding, landslides and wind sedimentation can cause tree burial but it's rare. In our landscapes the most common culprit is planting too deep and settling after planting.

Trees almost universally flare out where the roots differentiate from the trunk tissues.

This basal flare should be your clue to correct planting depth. The flare should never be completely buried and should generally be at the surface or just slightly above. This translates to a centimeter or half inch or less above the surface of the soil. If you see a tree that looks like a pencil coming out of the ground, strait with no flare at the base it is likely planted too deep. Trees want to grow roots in a downward direction, this is called geotropism and ensures roots remain in the ground and not heading to the sky.

The process of planting a a tree or shrub often starts with a hole in the ground that is more suitable for a fence post or pit barbecue than a plant. Trees do best if planted in shallow lens like planting sites that are wider than deep. Care must be taken in most soils not to glaze the outer edge of the planting site by packing it while shoveling. Once you are done take the side of the shovel and break up the hard polished soil so the roots can easily penetrate it. If the tree requires staking once planted do so loosely and be sure to have a plan in place to come back and remove the stakes and wires once the plant has settled. If in doubt when planting trees contact your ISA Certified Arborist they are the go-to experts on tree planting and care.

Too Mulch of a Good Thing

Mulch was touted as the cure for all things soil related when it first introduced in the early eighty's and has been used with much success and notable failures since. Research is currently underway to see if our current mulching practices are of benefit. To understand how mulch benefits trees we must have a few basic facts about the soil it protects.

Mulch is a protective cover for soil. Soil is an environment that contains solids, gases and liquids. As long as they are in the right proportions they work in conjunction to create the ideal habitat for roots. If they are out of proportion or not present at all they exclude roots and prevent plant growth. Too many solids and soil becomes compacted and roots can't get enough oxygen and die failing to penetrate the soil. If you have roots coming to the surface of your lawn this is the problem. If you have a high water table there isn't enough oxygen in the soil roots will be excluded. Too little water in the soil and trees and plants will dry up. If the temperatures in your soil swing wildly from hot to cold many plants will suffer root injury and possibly die.

Trees growing in the forest develop their own natural layer of mulch called “duff” this consists of many years of decaying leaves and debris that falls from the trees forming a rich insulating mat on the forest floor. The forest duff reaches a state of equilibrium decaying at a rate that prevents it from suffocating the trees that produce it.

Mulch often isn't made from the same types of trees that are being mulched. Some mulch, coming from trees that don't decay readily, like cedar mulch, can build up. Mulches made of dense materials like shredded leaves can prevent air infiltration and must be used sparingly. If mulch becomes saturated with moisture and prevents air infiltration roots will migrate in to the mulch and cause growth problems. Roots that grow into mulch will often circle the tree eventually girdling and strangling the tree. The problem is made worse by trees that are planted too deep or in pits. They are trying to grow roots out of the hole they are buried in.

Proper mulching is an ongoing process and requires inspection and occasional maintenance. You really can't just keep adding it year after year and expect it not to have negative effects. Recent innovations in mulch delivery, namely blowing it into place have made this “ Mulch Glacier Effect” a more common eventuality. To explain, if the mulch is being deposited faster than it is decomposing it builds up into a mulch glacier and starts to move down slope! It also piles up around the trunk of the tree and starts it to decompose. Trees are made of wood, a surprise to many, and placing wet wood against it causes it to decay.

Photos S. Smith

I have included two pictures that show soil profiles before and several years after a deep layer of mulch was placed on a compacted turf area. Notice the change in color and the development of rich organic loam horizons deep below the surface.

I'm still a fan of mulch applied right. Contact your ISA Certified Arborist to see if your mulch is correctly applied.

Emerald Ash Borer Update

As this potent pest inches closer to your property, do you have a plan in place to protect your valuable Ash trees? Treating your Ash trees before this bug arrives has proven effective in protecting Ash trees from this deadly pest.

Emerald Ash Borer (Agrilus planipennis)was discovered in the Detroit region in 2002 but was likely established in that area in the mid 1990's. This small brilliantly green insect, is from China, where it is a minor forest insect living on weakened Ash trees in it's native forests. Our native Ash trees have no natural resistance and are excellent hosts to this pest. Once infested with this pest Ash trees decline and eventually die in 2 to 3 years Small or stressed trees may die in one season. As with many invasive pests that originate elsewhere, like the Asian Longhorn beetle, it has proven a destructive pest outside its native habitat. Unlike the Asian Longhorn Beetle it has tremendous reproductive abilities and is able to fly easily, spreading quickly.

One mode of transport this beetle shares with other destructive pests is it's ability to spread by hitchhiking on firewood. Workers from the Detroit auto industry have described unpacking containers of imported auto parts in the mid 90's containing wood crates and packing materials that may have been the original source of the infestation. This scenario is consistent with the beetles life cycle that includes pupating in dead drying wood. Efforts to eradicate the pest have been largely unsuccessful, leading one official to describe it as " cutting a hole in a donut". The beetles have often spread beyond the site of initial infestation by the time they are detected and treated.

Efforts are taking place to look for naturally resistant selections of Ash as well as locate natural predators that may reduce Emerald Ash Borer's destructive abilities. What can you as a home owner do to be prepared for this pest? If it has been detected in your area you will need to protect Ash trees you want to preserve.

First you will need to assess if you have Ash trees on your property and what the appropriate action you should take. If you have Ash trees and want to protect them, you should maintain the vigor of those trees with appropriate cultural measures. These may include fertilization, root stimulants and mulching. Once EAB is close to your area, there are proven systemic treatments that can prevent infestation by EAB. Preparation and prevention are your best defenses against Emerald Ash Borer damage. Current estimates of the risk posed by EAB are described as follows:

0-5 miles from a known EAB site- Extreme Risk,

5-10 miles from an EAB site High Risk,

10 miles and greater from an EAB site Elevated Risk.

If you are in an area that is at elevated risk you should be developing a plan with the help of your ISA Certified Arborist. Take the time to contact your ISA Certified Arborist today and have your property accessed for the potential impact of Emerald Ash Borer. Panic is pointless, preparation is priceless.

An Eye For the Ancient

V. Van Gogh

In my previous article I reviewed the basic concepts of Conservation Arboriculture. Two key points presented in that article were: the duty of care is squarely on the owner of the tree, and the perfect image of a young vigorous growing tree is as flawed as society's obsession with youth. We are finding out that life doesn't end at 40 or 65 and older people are vigorous, , continuing to make significant contributions way beyond mid life! Similarly for certain long lived tree species the benefits they provide to the environment and community increase exponential as they age. Simply put a tree that is twice as old will provide four times the benefits. Here is an site that allows you to calculate the approximate value of the benefits your tree provides each year to you and your community. You will be surprised and don't forget this is just for one tree.

http://treebenefits.com/calculator/

We are all familiar with the figure of the young mature tree with arching branches gracefully reaching to the sky.

This is the picture we usually have in our minds when we think of a tree.

What we are not thinking of is the gnarled trunk and stubby branches of the veteran tree.

The silhouette of a young vigorous tree makes it all to easy to write off an older declining tree as “ hazardous” or not worth the risk of keeping it.

I'm an advocate of planting, this is a key part of any tree plan however I have long been a proponent of saving trees. What we need to do is realize that the veteran tree is alive and providing tremendous benefits. Older trees provide habitat for an enormous variety of living beings contributing greatly to the diversity of the forest. Birds, mammals, insects, spiders, plants, fungi and microbes all live and develop webs of inter-connectivity in Veteran Trees.

If you have ever walked in a tree plantation with even aged trees the lack of diversity will be immediately apparent. Tree plantations and working trees have their place and are valuable. They typically are not very biologically diverse environments. Studies have shown an ancient tree in a forest grove may have 90% of the biological diversity in the whole grove.

We need to take a close look at the Veteran Tree with an eye on preservation rather than simply on hazard reduction.

As trees age they begin to die back from the tips, creating stout thick branches and stems with numerous adventitious sprouts that look grizzled and somewhat bizarre. This doesn't mean the tree is beyond hope! Its a natural response to aging.

Take the time to look at Veteran Trees, see how they have adapted and continued to survive. Recognize the beauty of the Veteran Tree. If you have an aged tree, take the time to contact and ISA Certified Arborist who specializes in conservation arboriculture and have them examine your Veteran Tree. You may save and old friend.

Whats's Old is Ancient

While it is difficult to sell tree preservation techniques that have been practiced for hundreds of years as new, reexamining ancient tree cultural methods may be just what we need to do. I have been interested in preserving trees right from the start of my career in arboriculture. I used to camp and canoe along the Souris River back in the 1980's and was amazed to see what was then billed as a 500 year old Burr Oak. Even then I remember being underwhelmed by its stature. Thirty years later it is still standing and I am only now able to see the beauty of its aged form. As an ISA Certified Arborist I am required to participate in a minimum of ten hours of continuing education per year to maintain my certification. Beyond maintaining my certification CEUs keep you current with the latest techniques and methods. Most legitimate professional accreditation programs realize that with research, methods and concepts change and what you took as fact yesterday may be proven to be fiction or close to it by the latest scientific research.
As part of my CEU requirement I was excited to participate in a two part session with Philip van Wassenaer, a preeminent expert on “Veteran Trees” from Eastern Canada.
For many years fear of litigation rather than solid research has driven the field of arboriculture when it came to dealing with vintage trees. No one wants to see anyone get hurt, but there are individuals and tree companies that offset their expenses and increase their income by playing on peoples fears about older trees. The duty of care for aged trees falls squarely on the shoulders of the property owner, but they should be well informed and presented with treatment options that include preservation as well as removal. Taking these ancient giants down unnecessarily struck me a bit like drinking a fine bottle of wine just to get the 10 cents bottle deposit. Modern arboriculture has evolved from the techniques of tree surgeons and plants men of a hundred years ago and is now reexamining the very techniques that may have been discounted.

The first step in conservation arboriculture is a thorough examination of the tree to possibly be preserved. Hollows and cracks along with declining canopies do not necessarily mean that a tree removal is imminent. Carefully examining the tree with modern methods will allow a current accurate diagnosis of the long term viability of the tree as well as its hazard potential.
One of the greatest revelations from the presentation and the too short field trip was grasping the concept that trees grow for a long time, and go through senescence for a longer time. Just as the youthful or mature form of the tree has great beauty so can the gnarled battle worn veteran be a beautiful presence in the landscape. With this new knowledge I rushed to the computer and found an image of The Souris Old Oak Tree and it is in exactly the beautiful mature form that Philip had described.
If you have a “Veteran Tree“or are interested in tree preservation contact an ISA Certified Arborist who is knowledgeable in the techniques to preserve and maintain these ancient giants

Time to Plant

The best time to plant a tree was 20 Years ago the second best time is right now. This old Chinese saying gives us pause to think at this time when our thoughts are far removed from planting. If you're like me you have already started to receive and peruse next years garden catalogs. Its nice to look back over the past years or years plantings and reflect on what worked and what didn't . I started planting back in boy scouts and haven't stopped!

I was driving along mountain road a few years back and was surprised to see that a forest had grown where there was only marginal farm land in the early seventies.

There is much that can be done individually and even more that can be done locally . This is an age of local actions and global results. No one is going to pick up the shovel for you or locate the trees or find a suitable site!
I have given these key steps in reverse order intentionally, now we will review them in the order they should be placed in. Before you can plant a tree or trees you should always have a site plan. If you are planting in your own yard you may not need permission, if you are planing a public or common space planting you will have to determine who the proper person or persons are to get access. See if they have a policy in place and have a brief idea of the location you would like to plant in. Having a plan In place will help you to clearly articulate your intentions to the appropriate persons and make it easy for them to give you directions and prevent confusion.

You may want to plant alone or with a small group of helpers. Tree planting is a lot of hard work and is also a lot of fun. Selecting the right tree for your chosen site is very important. this would be he right time to consult your ISA Certified Arborist who will be able to help select the correct tree for your site. Once you have planted your tree make sure you have a plan for after care. Trees planted in yards typically have better soil conditions and nutrient levels then those planted in boulevards or along streets. Arborists are experts on local planting conditions and may advise you to have a soil sample taken to test for fertility.

The larger the tree you are planting the longer it takes for it to recover from transplant shock. The generally accepted rule is an inch of trunk diameter per year of recovery. For example. One inch in diameter tree, measured at 4 feet above ground, will take one year to reestablish itself and start to put on new growth , a two inch- two years and so on. The larger trees really give immediate visual impact but are harder to reestablish and more prone to failure. This is probably why the small trees I planted , only a few inches tall, survived without much help after being planted by unskilled pre-teens who struggled to handle a spade!

ISA certified Arborists are tree experts and the original tree huggers who have the Skill and knowledge to help make your planting a success. Reach out to your Arborist and get his advice on your planting project and success will be much improved. You may not be able to plant today but you will be able to plan.