The Yellow Farmhouse Garden

June 23, 2011

Catalpa Trees in Bloom

Filed under: Trees — bob @ 12:37 pm

Those trees covered with white flowers we have been seeing are Catalpa trees.  To me, a well-formed, fully grown Catalpa is an impressive sight.

A mature Catalpa tree blooming in rural Monroe County.

Catalpas have other positive attributes other than their flowers.  They grow fast compared to many other trees and can reach a height of 50 feet.   Catalpas tolerate the stressful growing conditions of a city environment, which is why so many were planted in urban areas.

In years past, farmers planted Catalpas to use for fence posts because the wood is resistant to rotting when in contact with the soil.  Nowadays, like everyone else, farmers buy their fence posts.

After flowering, long, slim cigar-shaped seedpods will form where the flowers once were giving the tree its nickname “Cigar Tree”.  These pods hang on all winter.

Not everyone likes Catalpa trees.  The branches are brittle and can break off during storms.   Some people feel its shape and large leaves give it a coarse, unrefined look.  I have to agree that a Catalpa struggling to survive in a difficult spot can look pretty ragged.   In addition, the flowers and seedpods make a mess in the yard after they fall off

Catalpa worms, the caterpillar stage of a sphinx moth, are sometimes found eating catalpa leaves.   Anglers use these worms for fish bait; fish love catalpa worms.

I remember when I was a youngster some Umbrella trees in my Grandmother’s garden.  There was a row of them, about eight feet high with a tuft of leaves growing out of the top.  Those trees were catalpas grafted with a bud from a dwarf form of the tree.   Every spring she would cut back the last season’s growth forcing the tree to form a new umbrella.   It made quite an impression on me.  The Umbrella tree form is still available at nurseries.

Catalpas are such a versatile tree, no wonder they have been so popular for so long.

Bob

June 3, 2011

Plum Curculio Damage on Apples

Filed under: Fruit,Insects,Trees — bob @ 10:08 am

The cold, wet spring we had is fast becoming a distant memory now that nice weather is finally here. One thing that keeps reminding me of spring is the insect damage I see on my apples.

It was difficult for me to spray the apples at just the right time in between all the rainy days we had early in the season.  As a result, my apples are showing signs of plum curculio damage.

The plum curculio is a small (1/4 inch long) beetle that attacks apples, pears, peaches, cherries and of course, plums.  The adult female emerged a couple of weeks after the apple blossoms fell.  That’s when I should have sprayed. But, it was rainy and I was gone for a few days and missed the critical spray.

The adult female curculio cuts a crescent shaped slit in the skin of the apple, and then lays an egg under the flap of apple skin.  The egg hatches and the tiny worn that emerges starts eating the young apple.

Plum curculio damage on developing apples.

Many of these damaged apples will fall off; some will stay on the tree and grow to full size but will have scars left from the curculio attack. The cherries, peaches and plums won’t be so lucky; they will all fall to the ground carrying the growing curculio larvae with them. There they will grow.  As they reach full size, the burrow into the soil. Later in the summer, the mature curculios emerge from the soil and feed for a while before they hibernate under the leaves for winter.

The plum curculios are still be laying eggs at this point in the season, so it is a good idea to keep up your spraying routine. Other pests will be out in the orchard attacking your fruit trees too.

Bob

April 13, 2011

Over-Wintered Orange Trees

Filed under: Fruit,Greenhouse,Trees — bob @ 9:58 am

We brought out our two Valencia orange trees during the warm spell we had earlier in the week.  I figured the really cold weather was behind us for the most part.  These trees are about 5 feet tall and are in 18 inch terra-cotta pots.

The two trees are part of an informal experiment I have been conducting over the past two years.  They were not kept in a greenhouse or even in the house in front of a south window; instead I put them into our semi-heated garage.  They each received some sunlight from a small south window; the size of window you would expect to find in a garage.

The temperature ranged from the upper 30′s F to lower 40′s F through most of the winter.  There were a few days when the heat was raised a bit up into the 50 degree F range.

I cut way back on watering.  They received water only five or six times during the whole winter.  I let the leaves start to wilt before I even thought about watering.  Then I watered just enough so the water began to drain out of the bottom of the pots.  Neither pot had a saucer under it so they didn’t stand in water.  They didn’t get any fertilizer either.

About mid-winter, the trees looked like they went into a kind of semi-dormant state.

Even though the trees seemed to be hibernating, the oranges that were on the tree last fall turned orange and ripened.  The fruit  didn’t get much bigger which is no surprise considering the lack of water.

There are quite a few oranges on our over-wintered orange trees.

Last night it got down to 33 degrees F and I left the oranges outside.  They looked perfectly fine this morning; they are used to the cool temperatures.

This is a good way to keep trees like these over winter if you are short on space in your house.  You don’t have room in the garage either? … well I can’t help you there.

Bob

August 31, 2010

New Threat to Walnut Trees

Filed under: Disease,Insects,Trees — bob @ 9:08 am

Another potential disease problem is over the horizon threatening our local trees.  This time it is the Black Walnuts that are at risk.

A fungal infection called Thousand Cankers has been killing Black Walnut trees in the western part of the United States for several years.  It has been confined to nine states in the Rocky Mountain area and westward until July of this year. Its range seemed to be associated with a different walnut called the Arizona Walnut.  Black Walnut is not native to that particular area but was brought in and planted by arborists, landscapers and others.

This summer it was confirmed that the disease had spread to at least one location in the Eastern USA,  Knoxville Tennessee.  Scientists now believe that it may have been present there for a number of years without anyone knowing about it.

At this time Thousand Canker disease is NOT present in Michigan.

The disease is caused by a fungus which is carried by a very tiny beetle called The Walnut Twig Beetle.  Despite its name the Twig Beetle  attacks larger branches or even the trunk of Black Walnut Trees by tunneling under the bark. They leave small “galleries” or tunnels in the wood caused by the beetle larvae feeding there.

When the larvae mature into adults they emerge from the branches out of small holes chewed through the bark. The fungus then infects the damaged area and causes a small lesion or “canker”.  These cankers spread very fast and merge together eventually moving from the outer bark into the cambium layer.  Each branch has a tremendous number of cankers which is how the disease got its name.

The cankers themselves are often difficult to see and identify.  A special lab test is needed for positive identification.

There is no cure or control for either the Twig Beetle or Thousand Cankers, plant pathologists are working on that though.

In the meanwhile we can help slow down the spread of this problem by not moving firewood just like we do to prevent Emerald Ash Borer from spreading.

There is no federal quarantine on moving wood products but the State of Michigan has issued its own quarantine against shipping articles made of wood from certain western states.

The USDA Forest Service has a good publication on this problem.

As I mentioned earlier, Thousand Cankers is not present in Michigan at this time. Keep in mind that there are a lot of other things that can cause a tree to show signs of  die-back  other than this disease.

Bob

June 30, 2010

Lichens on Trees

Filed under: Other Organisms,Trees — bob @ 3:21 pm

A few days ago a gardener proclaimed to me that an expert had told her that Lichens are found only on trees that are no longer growing. I don’t know what expert might have told her that but I’m sure she misinterpreted whatever may have been said.

Lichen growing on young crab apple tree.

The study of Lichens is a huge branch of Biology in and of itself. People who take an interest in that field of study often become quite rabid about the subject. I’ve been on expeditions where the Biologist talked as if the world existed for the sake of providing a place for Lichens to grow.

Lichens are actually a combination of two organisms, a fungus and an algae. They work together as one in order to survive in places where they couldn’t otherwise. The algae provides energy through photosynthesis while the fungus provides shelter and a place for the algae to live.

They can be found covering a wide variety of objects in addition to trees including rocks, roofs, bare soil and just about any other exposed surface.

On trees Lichens are harmless. They are actually quite attractive on trees adding an extra visual element to the landscape. Many gardeners will go to extreme lengths to get Lichens established on certain features in their garden. Lichens growing on the roof, on gravestones or other unwanted places is a whole different subject that we won’t cover here.

As for the gardener who thought that Lichens can be found only on non-growing trees, all she has to do is look in her own yard to see that Lichens are quite happy on actively growing trees.

Bob

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