The Yellow Farmhouse Garden

October 25, 2019

Evergreen needles turning yellow

Our 2019 growing season is over. The Detroit/Pontiac National Weather Service office made the official announcement declaring October 18th as the date, so no more frost/freeze advisories until next spring.

So now we are into the third week of October and the leaves on the trees are all turning color except for the evergreens. “What? Wait!, the needles on my pine trees are turning yellow. What’s wrong?”

Even though pines, spruces, arborvitaes, firs, hemlocks and others are called evergreens, that doesn’t necessarily mean all of the needles are always green all of the time, forever.

A certain amount of color change on evergreens is a normal event this time of the year. Some years it is more pronounced than in other years. This year many of my white pines are turning a vibrant yellow that can be seen from quite a distance away. The yellow-colored needles next to the fresh green are very attractive but could be a cause of concern for those not aware of this natural occurrence.

This particular white pine tree has a large number of yellowing needles. The needles on the ends of the branches are all green indicating a healthy tree.

This particular white pine tree has a large number of yellowing needles. The needles on the ends of the branches are all green indicating a healthy tree.

Later on in the season, all of the yellow needles will drop from the trees and add to the pine needles collected at the base of the trees contributing to a healthy mulched layer. It’s nature’s way of making sure pine trees have a healthy soil environment. Very few, if any, other plants will grow in this mulched area eliminating competition for growing space and nutrients.

All of that mulch started out as green needles that eventually turned yellow and fell. Because needles are thin they are not blown around as far by the wind like the leaves from deciduous trees. Once they land, they tend to stay put.

My cedar trees, on the other hand, are not turning color this year. During some years, some of their leaves will turn a tan color.  Virtually all evergreens go through this process in one form or another.

Don’t confuse this with pest problems. Things like bud worms will cause symptoms of yellowing or die back from the very tips of the trees where the leaf buds are located. The natural seasonal yellowing takes place on needles located away from the tip of the branches. I’ve also seen evergreens damaged by lawn weed killers. Trees poisoned by an overdose of lawn chemicals will drop needles too.

Bob

June 28, 2019

Getting back on track spraying fruit trees

Filed under: Disease,Fruit,Pesticides,Trees — Tags: , , — bob @ 3:11 pm

The almost daily rain we had this spring really put a damper on fruit tree spraying. Pesticides work best if they are applied at least 24 hours before a rain. When a rain happens before the next spray, the effectiveness is reduced as the material begins to wash off. Even a light rain can wash off a percentage of the spray. Heavy rain can remove almost all of the material allowing diseases and insects to get a foothold. So you can see how difficult is was spraying fruit trees this spring.

But now it looks like the weather has finally straightened out allowing us to get back on a regular pest control schedule. It’s too late to do anything about pests that emerged early but summer spraying can control later emerging pests like apple maggot, codling moth, peach tree borer and others.

Backyard fruit growers often use an all purpose fruit tree spray mix that contains a combination of insecticides and fungicides to control a wide variety of pests. It’s much more convenient to use and store a single container than a shelfful of assorted specialty materials.

All purpose sprays are applied as often as every week or two, or as few as twice a season, depending on the formulation used.

There’s a few things to keep in mind when mixing and applying pest control chemicals. These things are always printed on the label but in my experience,  I find that not everyone reads all of the fine print. A common mixing ratio is one or two tablespoons of product per gallon of water — that’s not very much. It’s tempting to pour in extra because it looks like that can’t possibly be a big enough dose to work, but it really is. Some people think they can approximate the ratio by pouring a quick dash from the bottle into their sprayer tank. I can guarantee that will always result in a much more concentrated solution than necessary. Always take the time to measure your materials carefully.

Adjust your sprayer’s nozzle to the most efficient spray consistency. A fine spray is more likely to be atomized, like perfume from an old-fashioned perfume bottle, causing it to be blown about even in a light breeze. You are more likely to inhale finely suspended materials in that case. On the other hand, a very coarse spray will not give you consistent coverage resulting in too much material in one spot and not enough on another.

Wait until the air is calm before spraying to avoid spray going all over the place except where it’s needed, including in your face. Early morning is best because the air is usually still and pests are at rest and have not started flying around yet.

Spray all surfaces of the tree leaves, don’t just make a spray over the top of the tree. Pests often spend time on the underside of leaves. And spray deep into the center of the tree. One major reason for pruning fruit trees is to allow sprays to penetrate into the tree without a lot of unnecessary leaf growth getting in the way.

To get the most protection for your tree, apply enough material until all leaf and stem surfaces are completely covered with adequate amounts of material. With all purpose sprays, that means until the spray just begins to drip from the tree.

Spray all surfaces to control hidden pests.

Spray all surfaces to control hidden pests.

I always try to mix just enough spray so that none is left over.  Any small amount that I have left over gets applied evenly over my trees until it’s gone. Both conventional and organic chemicals will lose their oomph if left in the sprayer tank for any length of time and can corrode, plug up or otherwise damage sprayer parts. Always rinse out your spray equipment right after each use.

Bob

 

June 8, 2019

Weather related disease problem on sycamore trees

The extra rain and cool weather we’ve been getting has been a mixed blessing. It’s June and a lot of gardens, farms and fields haven’t been planted yet because of saturated soil and cool temperatures.

On the other hand it has been great for established plants like trees and shrubs. In most cases they’ve made tremendous growth except for one notable exception — sycamore trees.

It’s quite startling to see how little progress the sycamore trees in our area have made. Most of them have very few leaves on them at all.

The maple tree on the left is flush with new leaves while the sycamore on the right is nearly bare.

The maple tree on the left is flush with new leaves while the sycamore on the right is nearly bare.

This is due to a disease called anthracnose, a fungal malady of sycamores that is present in varying degrees from year to year. This year’s outbreak is particularly severe due to unusual weather.

A lot of it has to do with timing. Rainy and cool conditions that occur a couple of weeks after bud break allows the anthracnose fungus to thrive. The longer that type of weather stays around, the worse the infection gets. That’s why our sycamores are looking so bad for so long this year.

There’s really nothing practicable we can do to cure or even prevent this disease.

Young leaves killed by anthracnose

Young leaves killed by anthracnose

Fortunately, once it gets warmer and drier they’ll bounce right back. Most of the time, very little major damage is done to the trees. The most obvious permanent damage you’ll see is “witch’s broom” a disfigurement of the branches that occurs in the spot the fungus killed twigs. At that point several small branches will grow from a single point giving it the typical witch’s broom appearance. Once the leaves fill out, however, the disfigurement is not so noticable.

Witch’s broom caused by anthracnose.

Witch’s broom caused by anthracnose.

Dead twigs eventually fall to the ground and can cause a mess in the lawn. This is probably why some people think of sycamores as messy tree, but it’s not the poor tree’s fault.

Trees can be sprayed or treated but it really doesn’t do much good since the infected parts can’t be healed anyway. Waiting for the weather is the best course of action in most cases. It extremely rare for a tree to die from anthracnose unless it is under stress from something else such as being planted in the wrong area or has a lot of bark damage from lawn mowers.

A little bit of fertilizer may help your tree to grow back its leaves faster. Generally, trees growing in lawns will get the nitrogen they need from the fertilizer used to fertilize the grass.

Anthracnose will always be with us so it’s just something we’ll have to live with.

Bob

 

May 16, 2019

Ornamental pear trees may become invasive in the future

Ornamental Bradford pear trees are in full flower right now. They must be everyone’s favorite tree, or you would think so because everywhere there’s a housing development there’s at least one Bradford pear tree planted in front of every house. Even municipalities and businesses are planting them.

They do have a certain charm and they’re quite eye-catching when they’re in full bloom. But there’s so many of them now that they’re beginning to just become part of the background visual-noise instead of  being an accent in the landscape.

Landscapers plant Bradfords because of their flowers, shape and moderate size, and even though they are an introduced species, they are believed to be non-invasive by many. That has been the case in Michigan until recently. There’s evidence that these trees have become tired of being well-behaved and have decided to cut loose from their suburban lawns. This was pointed out to me a couple of years ago by a local, well-respected naturalist. To drive home her point she said all you had to do was look at the number of wild Bradford pears growing all along the highways.

Well, I drove the entire length of I -275 this week and was surprised how many out of place Bradford pears there were. They weren’t overcrowding any one area but there were plenty of single trees and small clusters of them. When you’re looking for them you begin to see them everywhere.

Even though this tree was covered with flowers, no bees were around. Bees seem t prefer other kinds of flowers if given the choice.

Even though this tree was covered with flowers, no bees were around. Bees seem t prefer other kinds of flowers if given the choice.

These more boisterous, escaped trees are claiming some area for themselves and have the potential to push out the native plants. The conventional wisdom that they are sterile and unable to reproduce may be true but something is going on. It brings to mind what Jeff Goldblum’s character Ian Malcolm said in the movie Jurassic Park, “Life uh, finds a way”.

In some other states Bradford pears are already a big enough problem that they have been place on those states invasive species list and are no longer recommended for planting.

To be fair, Bradford pears may never become a problem for us. I remember early in my career when, for a short time, some people worried smoke trees might escape and become invasive. Some trees did take root out of place here and there but the smoke tree invasion never materialized.

Maybe it’s time to think about developing a replacement for the Bradford pear if for no other reason than to add more variety to the suburban landscape.

Bob

April 17, 2019

Reproduce forest soil to help trees get off to a good start

Filed under: Shrubs,Soil,Trees — Tags: , , — bob @ 5:26 pm

Spring is the best time of year to plant trees. During the winter the dormant buds and roots are in a kind of holding pattern until the right growing conditions happen in the spring. Then they have the entire growing season to establish themselves before next winter.

No doubt you’re aware of the requirements for a proper sized planting hole and the need to water the young tree after planting. Proper planting depth is also very important. I’ve mentioned in previous posts how important it is to remove the wrapping from the root ball, even though it can be a hassle.

I always set aside any sod and never use it to back-fill the planting. Actually, I don’t use the topsoil to back-fill either. I just use the subsoil from the hole for back-fill and save the topsoil for the very top of the hole. That way the original soil profile is maintained.

After I’ve taken great pains to get the tree into the ground, there’s one more thing I like to do to and that is to create an artificial forest floor covering.  It’s something I’ve been doing for decades and I like the results.

It’s really a way of mulching that small trees seem to respond to. I first apply a thin layer of partially decomposed wood chips around the newly planted tree, over the topsoil,  maybe a couple of inches deep. Then I cover that with a layer of chopped leaves. Chopping the leaves prevents them from matting down which can slow down rain water penetration into the soil.

Here the mulch is applied  about four feet in diameter.

Here the mulch is applied about four feet in diameter.

The layering combination of subsoil in the hole, with topsoil over that then covered with the chips and leaves mimics the soil conditions of a forest. I don’t mix the layers, I let the soil microbes do their thing. Eventually as the mulch decomposes, humic acid and related compounds are formed providing an environment for a wide variety of beneficial soil microbes. All of that allows the tree to adapt to its new home and grow to its full potential.

Not everyone will want to fuss with their trees like this and some will say it’s overkill and I certainly wouldn’t expect a landscaper to do it. but it’s something I’ve found to work for me.

Bob

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