Why we don't just fertilize when plants look sick.

The first picture shows Rhododendrons that have been in the ground about five years. They look yellow and a good candidate for fertilization.
The second picture shows the roots from one of the plants in this group that died. You can still see the shape of the pot that the plant came in from the nursery. These plants have never sent roots out to the surrounding soil and fertilizer would be a waste of time and money. These roots should have been cut and spread out at planting. Some of these plants may still be saved by using a sharp shovel to cut the roots at a few places radially to the plant. In a year after this treatment fertilizer will probably then be a benefit.




Sometimes even trees that are not planted too deep or mulched to death develop root problems. It is always worth a check if other causes of decline can not be determined. One clue that a tree may have root problems is that other trees next to them look fine.

This tree is not doing well. The pictures that follow show that this tree has cross roots (roots that grow over other roots) these were cutting into the main roots of the tree. See the big gouges in these roots after I cut off the offending roots. Unfortunately this is not an exact science, some cross roots were left until the tree recovers and will be removed at a later date.





Not the best Photo but I think you can still see the large root that I left for another time.

This next tree is about ten feet from a driveway and at the bottom of a slope. For some reason, probably run off over the years one side of this tree was about nine inches too deep. This usually causes girdling roots (the roots you can see circling and gouging into the trunk). Unfortunately by the time I thought to take photos I had already cut off some of the worst offenders. I think you can see the gouges and some of these offending roots.


(With apologies to the memory of Sir Walter Scott)
Oh what a tangled web we weave
when first we practice burying trees.

The sister tree to this sick looking maple is dead. Look how deep it was. This tree had no chance of survival. What a waste of money and trees. The last picture in this series shows a tree planted correctly. Note you can see the butt swell and the top of the first major root.



The following trees are examples of typical landscape trees being volcano mulched to death.
I guarantee that most of the trees in this parking lot will be dead within ten years and probably much faster. So someone paid to have these trees killed.


If any one ever reads this blog they are probably thinking boy this guy is a nag about his roots and stuff. Probably true but it really irks me to see people wasting money and killing plants.

The root work on these trees was done by exposing the roots with a tool called an air spade which blasts air at high pressure to remove the soil. You can use a hose to take a look if you are curios about a tree you have. A hose will make a huge muddy mess if you want to do more then just take a surface look. Forget trying the rake and shovel unless you like grueling heavy work. The air spade also will not damage roots like a shovel and rake. If you are feeling adventurous here is how I built my air spade.

If you do find root problems, roots can be removed with a chisel. Try to make clean cuts and do as little damage to other roots as possible. As I mentioned before there is no scientific amount of roots that you can remove and be sure not to kill the tree. If in doubt and you want to try this yourself you can do one side of the tree one season then the other side the next season.
If you do it this way do the worst side first.

As for the time of year to do root work, I am told that it does not make a difference. Obviously you can't do it after the ground is frozen. I do not think it prudent to do this between the leaf drop and leaf out of the deciduous trees. It being my thought that why cut off roots that the tree has spent energy on to fill with food.

After serious root pruning keep the tree watered, but not waterlogged for a while. At this point a light application of root stimulator fertilizer can benefit the tree. Root stimulator fertilizer means no, or very low nitrogen, you do not want to encourage top growth that the roots can't keep up with. I prefer just compost, you can't go wrong with compost and it has anti-fungal, anti-viral and anti-bacterial qualities that can't hurt.

Now a short bit about weather. Both drought and too much rain can reduce the root mass of a plant. The worst situation is drought broken by a lot of rain the next year. The effects of drought can affect a tree for several years following as the roots take time to grow back.

Improper fertilization of trees sick from drought, too much water, diseases, insects, root and other problems can do more harm then good.

Switching to integrated pest management

When you turn your landscape over to an integrated pest management (IPM) system there are some things that you need to know and expect.
First if you have been treating the old way of spraying your plants routinely with broad-spectrum insecticides, switching to the more environmentally sensitive integrated pest management can take time to show results. This is because of the reduction of predators that will have taken place. You can expect that in some circumstances you may get a temporary build up of pests until predator populations recover. Don’t let this panic you; you may need to do a few more targeted treatments in the beginning. Long term however, as pests and predators are managed, using integrated pest management will lead to fewer problems as the balance of nature returns.
Secondly your integrated pest management technician has to be your partner, and you may need to supply, and ask for information.
Case in point. I have a property that I have been working on for three years now, carefully choosing treatments and timing so as to control pests and maintain a good predator balance. This property has always maintained a healthy population of lacebug on a few Azaleas that are close to the woods, even with spring and fall oil treatments.
I was there yesterday and saw a note on the door from a mosquito control company.
Well the reason for the lacebug became obvious. The note had the chemical used to control mosquitoes and sure enough it was bifenthrin, which is a notorious killer of predators.
See how one thing that you do can cancel the efforts of your integrated pest management program. Many customers also treat pests themselves between visits. It is important to know what and how to treat so that your IPM program is not interrupted. It is fine to go out and treat, say for Japanese beetle, but you should learn to keep with the program. Don’t run out and treat the whole yard with anything that the sales person says kills Japanese beetle, but treat only the effected plants with the right chemical. Your IPM technician should be able to help you choose treatments, and it is also a good idea to let them know what you are using. Resistance to chemicals is one of the things we work hard to avoid, and if you are using the same pesticide over and over again then I show up and use the same thing we could both be contributing to this problem.
The use of chemicals is just one part of good pest management, other things include but are not limited to watering, pruning, fertilizing and mulching.
Ask questions and if your IPM technician is bothered by them then find someone who isn’t. A good IPM technician should be happy to talk with you; a well-informed customer is a good customer and not something to be afraid of.

Whats out there 7/23/09

Recently I have been getting a lot of Questions about the growths on Oak and Maple leaves. Bumps and swelling on these leaves are sometimes green and sometimes colored and may have fuzzy white growths associated. A small insect called Eriophyid Mites causes these growths. They do not do any real harm to your trees and can be ignored. Some people even enjoy the look.

Eriophyid mites also attack hemlocks pine and spruce, on these trees they do not form galls, and can be seen at the base of the needles, but only with a good hand lens. They can build up to damaging populations on these types of trees. If you see a white hue at the base of the needles you probably have Eriophyid mite. Even high populations of this mite will not usually kill a tree unless it is stressed by other factors, and can for the most part be ignored. If you have a low tolerance to insect damage you can treat these mites with a variety of pesticides. Oil treatments in the spring and fall will help to keep the populations of Eriophyid Mite below damaging populations.

Lacebug, Mites, and Mealybugs are still in low populations.
Still raining and diseases are getting rampant.
Black Knot on Prunus sp. is everywhere.
Fire blight is quite prevalent.
Tar Spot on Maples is now showing up.
We are seeing a lot of a disease on our perennials and annuals.
So what to do now!
Fungicides are generally preventative and not curative so applying once a disease is established will not generally control the disease. A few products will have some curative effects on certain diseases and treatment will stop them spreading to unaffected stock.The best thing to do now is to rouge out infested plants and cut off infected leaves.
Black spot on roses is one of the diseases that is really a problem with all the rain.
Black spot is spread through water splash from infected leaves to other leaves. It is very important to cut off infected leaves. Fungicides can prevent newly emerging leaves from being infected. Wilt Pruf sprayed on leaves before rain will protect new leaves from Black spot, powdery mildew and many of the rain spread diseases but is not registered as a fungicide so you cannot legally use it for this purpose. A new Bio Fungicide has shown promise on many Bacterial and Fungal diseases.
The key to controlling diseases is prevention.
Keep plants well spaced for good air movement.
Watch the weather patterns and if you treat, treat before weather predicted is favorable for a disease.
Keep records of what diseases you have in a year so you know what preventative treatments you might need the following year if weather conditions warrant.
Plant resistant species and varieties when your records show that a disease is a problem in your area.
Control some of the pests that spread diseases such as Leaf Hoppers that spreads Aster Yellows, very early in the year. Clean up your beds in the fall and dispose of litter.
Composting is fine to kill most disease spores if done properly but some diseases
can survive the heat of a compost pile and should not be composted, or only composted in a pile that will not get used for a few years until the disease spores become non-viable.
Some diseases that can survive composting are:
corn smut; clubroot of cabbage, broccoli, cauliflower and other crucifers; Verticillium wilt of potato, tomato, pepper, and eggplant.

Links for more information:
Bacterial diseases

Good disease pictures

A really nice turf pamphlet.

Insect disease vectors

Pest control vs. Integrated Pest Management.

The old thinking of pest control; see a pest kill the pest is and has to change to the new thinking of integrated pest management.

So what is integrated pest management? Simply put it is using all available methods to keep pests below damaging levels. Methods include such things as choosing plants resistant to some of their natural enemies and suited for the environment. Cultural control, such as cleaning needles from under pines in the fall. Predator introduction and maintenance. (keeping some plants in the garden in flower for the whole season is a great way to keep predators around as many of our best predators have juvenile stages that feed on nectar.) Monitoring and determining the damaging threshold of a pest. The correct use of fertilizer and water (yes these can both affect pest populations), and the use of pesticides.

Why would you want to manage pests and not just kill them?
Good question.
Well the first thing is that the old pest control strategy was wrought with problems.
Just killing the pest does not always work in the long run. Pests become resistant to chemicals and you can wipe out the predators with just kill it strategies. Then you end up with super bugs and no predators. Even the great DDT that many farmers and mosquito control people whined about when it was removed from the market was, at that point becoming fairly useless in controlling mosquitoes. Already there was a great deal of resistance in mosquito and other insect populations and this was destined to get worse.
Killing one pest outright can lead to the multiplication of another pest that was present but not a problem. For example lets take the case of the Hemlock Eriophyid Mite and the Two Spotted Mite. So you want to kill the Eriophyid and you choose Sevin as it really does a great job killing this mite. Sevin however does not affect Two Spotted Mite mites in the least, but is horrible on this mites predators. Now you have no Eriophid Mites but a population explosion of Two Spotted Mite. So you just traded one problem for another and spent money for the privilege.
Not to mention that Eriophyid Mites will rarely build to populations that severely damage a plant. Note that I am not badmouthing Sevin, used properly for the right pest at the right time this product can be the suitable choice.

Does this mean that in integrated pest management we do not ever try to kill every pest?
The answer to that is no, sometimes it is the right way to go, but we choose our battles and the results we want from them more carefully.
You want an example do you? OK invasive species are one reason where it might be good to use a wipe out strategy, as these pests usually have few or no natural enemies. If there were a product that would kill every Asian Longhorn Beetle but decimate natural predators in the area it would be the obvious choice to use the chemical even with the loss of predators. Asian longhorn beetle will destroy all favorable trees in its path, like a B science fiction movie. So even though native pests would, for a time, get worse due to the predator loss these natural predators would recover and nature would resume it’s balance.

Levels of acceptable damage are different and depend apon the pest, crop, use, personal preference and other factors. One dandelion on a golf green is one two many, but would not even be noticed on a highway median. One Asian Longhorned Beetle is one to many, but ten European corn borer in a patch of Zinnia may be acceptable.
The correct application of Integrated Management may leave a residual population of pests in an area. The good technician will evaluate the pest, the population, the available natural predators and the potential for the pest to reach damaging levels for the situation before deciding if and how to treat the problem.

So if in integrated pest management we don't try to kill all the pests, why not just go totally organic and let nature take care of everything? Under some circumstances we can and do, but we have changed our environments and in turn how nature can deal with problems. Even in a balanced system there are ebbs and flows in pest populations, and some times great losses. We often expect and need more than nature can give. If you look at an untreated apple tree, there will be apples on it but most people would not eat them even though they are quite edible; worms, apple scab and all.

Though there is still a lot of research to be done in the integrated pest management field, this approach has proven itself to be better then conventional pest control in many instances. The proof to this is that many farmers have adopted the strategy and have found that they have increased crop yields and reduced expenses.