The Yellow Farmhouse Garden

September 19, 2017

Spots on maple leaves

Filed under: Trees — bob @ 1:17 pm

In many cases, diagnosing plant problems requires an in-person look at the plant in question. Too many disorders look similar when all you have is a photo to go by.

Earlier this week someone sent me a photo asking about spots on a valuable tree they have in their front lawn. That was an easy one. I took one quick look at the photo and knew right away what it was. Their maple tree was infected with a fungal disease called “tar spot”. It’s quite easy to identify because in this case the name is very descriptive, the leaves really do look like they’re covered with spots of tar.

A classic example of tar spot.

A classic example of tar spot.

Even though it looks pretty bad, tar spot is relatively harmless even in a heavily infected  situation. There’s no good way of preventing the disease. Some years are worse than others for tar spot and some varieties seem to be disposed to having more dramatic symptoms than others.

The spores from the disease over winters in fallen leaves so you wound think that raking them up and disposing of them would help the situation. Unfortunately the fungal spores can travel for miles in the air and can land on your tree and take hold.

When a tree has a severe case of tar spot, it can lose many of its leaves causing the tree raking season tobegin earlier than normal.

One bright spot is: since tar spot is species specific, it will not spread to other types of trees such as oaks.

Bob

August 31, 2017

Sycamore trees lost their leaves

Filed under: Trees,Weather — bob @ 5:34 am

The stretch of dry weather we had took its toll on some sycamore trees planted in a less than ideal spot this season. Although sycamores can grow in dry areas, they thrive in moist soils. That causes a bit of a problem since the best spot to build a structure is on a high and dry area — the exact opposite of the what is preferred by a sycamore tree.

People love sycamores because of their maple-like leaves and unique bark. A healthy, thriving sycamore is a wonderful sight and is makes fine shade tree, although they can be messy. However, unless a building site has a low, moist spot, a sycamore should not be your first choice. When these trees are planted on the wrong site, they never get a chance to live up to their full potential. A dry site can actually significantly shorten their lifespan.

Powdery mildew is a plant disease that can show up this time of year on sycamores. And that is exactly what happened on a trio of sycamores I was asked to look at last week. Usually powdery mildew shows up first on the newest leaves, but on those trees so many leaves were gone, I was only able to find the fuzzy fungus growth on the few older leaves still attached to the tree.

This sycamore has lost virtually all of its leaves. Compare that to the maples in the background that have nearly all of their leaves.

This sycamore has lost virtually all of its leaves. Compare that to the maples in the background that have nearly all of their leaves.

Normally mildew is not a serious problem on sycamores, it causes leaves to drop but the trees bounce right back the next season. I’m somewhat concerned about those three trees. The combination of the dry site and powdery mildew may leave the trees in a permanent weakened condition. Healthy sycamores are fast growing trees but these seem to be languishing in that spot. The prescription in this case is to irrigate the trees as soon as the start of a dry spell is expected — every year from here on out.

Since trees can live for decades or even centuries, take some time to survey your planting site and match the tree to the conditions.

Bob

May 19, 2016

Remove burlap and twine from balled and burlapped trees

Filed under: Planting,Trees — bob @ 9:49 am

The balled and burlapped method of planting trees is very popular because it allows nurseries to dig, move and sell larger specimens than if the trees were bare-root or potted. It also makes it easier for homeowners and landscapers to plant. In landscaping, like in any other business, time is money which is why it can be tempting for some to cut corners when planting trees.

The most common of these cost-cutting items is dropping a balled and burlappped tree into a hole, replacing the soil, then mulching the new tree. From the outside everything looks wonderful but not taking care of the burlap or twine can prove to be devastating to a tree.

Wire, burlap and twine does not decompose in the soil as readily as some landscapers would like you to believe. To keep roots growing to their full potential, wire must be cut and removed from the root ball. It will not “rust right away” as we are often told.

I had an experience many years ago when someone asked me to move a tree for them that was planted five or more years earlier. It was going to be a big job. When I uncovered the top layer of soil I discovered that the landscaper had left the wire basket on the rootball. It was a simple matter for me to hook a chain onto the wire basket and just lift the entire tree out of the hole with a front end loader on my tractor and carry it to its new location. The tree looked like it just came from the nursery. The wire was still sturdy and the burlap was sound with no roots growing through.

Damage by twine left on root ball.

Damage by twine left on root ball.

 

The twine tree growers use to tie the top of the burlap does not deteriorate very fast either and will eventually cause major damage to or even kill a tree if it is not removed. As the tree grows in diameter, the twine stays in place and acts as tourniquet strangling the tree. It may take many years for symptoms to show.

The tree formed a callus around the twine as it tried to minimize the damage.

The tree formed a callus around the twine as it tried to minimize the damage.

Even the roots were not able to develop properly

Even the roots were not able to develop properly

Finally, the burlap cloth itself should at least be slashed to allow roots a place to grow into the surrounding soil — removing it completely would be even better.

If you landscaper tries to tell you that that leaving twine and burlap on the trees is standard practice, don’t believe it and insist they do it right.

Bob

 

June 10, 2015

See blooming satsuki azalea bonsai June 6-14

Filed under: Bonsai,Trees — bob @ 12:02 pm

I think just about everyone enjoys looking at bonsai, the Japanese art of growing miniature trees in containers. Even those who are not particularly interested in plants will stop and take a second look at bonsai.

The University of Michigan Matthaei Botanical Gardens near Ann Arbor, is offering a rare treat this month, Magnificent Miniatures a showing of satsuki bonsai azaleas in full bloom.

The azaleas on display are the species Rhododendron indicum.

The azaleas on display are the species Rhododendron indicum.

 

The plants are on loan from Dr. Melvyn Goldstein a renowned bonsai collector from Ohio.

azalea bonsai

The bonsai are flowering right now. And like other flowering plants, the flowers only last for a short period of time.

A fantastical shaped bonsai at Matthaei Botanical Gardens.

A fantastical shaped bonsai at Matthaei Botanical Gardens.

The show is free and runs from June 6 through June 14, 10 am – 8 pm daily. It’s an easy drive to the Gardens from anywhere in southeastern Michigan and northwestern Ohio. They’re located at 1800 N. Dixboro Road, Ann Arbor. It might not be a bad idea to call ahead and make sure the bonsai are still blooming. The phone number at Matthaei Botsanical Gardens is 734-647-7600.

Bob

 

 

 

April 29, 2015

Mulching around trees

Filed under: Trees — bob @ 8:59 am

As the days get warmer, more and and more people are out sprucing up their lawns.

After cleaning up winter debris, one of the first tasks people like to do is refresh the mulch around their trees and shrubs. Garden centers and hardware stores know this and stock up on piles and piles of bagged mulch.

Mulch serves many purposes but the two most common reasons for mulching lawn trees are the decorative appeal and protecting trees from mower damage.

One of the most common ailments of yard trees is “lawn mower disease”. This happens most often when someone mowing the lawn gets in a hurry and tries to get too close to a tree. The mowing machine then makes contact with the trunk of a tree and scrapes away part of the bark.

The wound leaves an entry point for insects and disease organisms to enter an otherwise healthy tree. Many times the owner is not even aware that his machine caused the damage.

When a tree is surrounded by mulch, you’re less tempted to mow close to the tree trunk.

Well-place mulch can give your lawn a crisp, manicured look.

Unfortunately, many people see commercial landscapes with trees poorly mulched by unskilled workers and try to copy that look at home.

The look I’m referring to is “volcano mulching”. I think you know what I’m talking about. That’s where mulch is piled up against a tree trunk in a volcano shape. They assume that is the proper way to mulch since professionals are doing the work.

Many homeowners have come to prefer that volcano look. I have had people actually get angry with me when I suggested they change their mulching technique.

Over time, volcano mulching damages the bark and the tree eventually struggles to stay healthy or slowly dies.

The proper way to mulch is to apply and maintain no more than two to four inches of mulch in a four to five foot diameter around the tree.

Do your tree a huge favor and say “no!” to volcano mulching.

Bob

 

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