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Do you have oleanders?  If so, you might have heard of a fatal bacterial disease called oleander leaf scorch that affects oleander shrubs.


This disease is slowly spreading and I have been seeing it more often when I visit clients.  


I wrote an earlier post about oleander leaf scorch, its signs and how it affects oleander shrubs, which you can view here.


Earlier this month, I visited another client whose entire backyard was surrounded by tall oleander shrubs that were quite mature.  She suspected that her oleanders were starting to show signs of oleander leaf scorch and it turns out that she was right.


Her suspicions began when she noticed browning of her a few of her oleander shrubs that began this spring and was worsening as summer progressed.

It’s important to note that browning of oleanders doesn’t necessarily mean that they are infected with oleander leaf scorch – browning can be caused by any number of problems from drought stress, salty soil or other excess minerals in the soil.


However, a closer look at the foliage showed some of the characteristics of oleander leaf scorch disease with the outer leaves and tips turning brown.

This occurs because the bacteria rapidly multiply, blocking the vascular system of the plant. 


These browning tips are also a sign of oleander leaf scorch, but this particular sign can also indicate high salts in the soil.

Even if you see only a few leaves affected, the entire shrub is infected and will die within 3 – 5 years.  Because this disease is spread by a flying insect called a sharpshooter, not all oleander shrubs in a given area may be affected as it hops from bush to bush.  However, these insects carry the bacteria in their saliva and spread it to each oleander shrub that they feed from. 

While I was able to tell my client that her oleander shrubs likely were infected this disease, the only way to confirm the diagnosis was to contact her local cooperative extension office and send in some leaves from her oleanders to be tested.

If the test comes back positive, she will need to remove all of her oleander shrubs.  While they will live 3 – 5 years after being infected, they will turn brown.  The most important reason for removal is to help keep the disease from spreading to other oleanders in the neighborhood.

For more photos and a detailed description of this oleander disease as well as a suggested replacement plant for oleanders, read my previous post, “Plant Disease: Oleander Leaf Scorch”
**Disclosure: This post contains an affiliate link of a product that I use in my garden and I recommend to those who are experiencing similar problems.
A week ago, I was called to see one of my regular clients to see how her landscape was progressing since she had installed a lot of new plants at the beginning of summer.
 
The majority of her plants looked great considering she had planted them at a particularly tough time of the year.
 
BUT, what caught my attention was her bougainvillea shrub.
 
 
The leaves were quite ragged and looked like something had been chewing them.
 
In addition, there were some small black droppings scattered among the leaves.
 
The diagnosis was relatively simple…
 
The culprit was bougainvillea looper caterpillars.  
 
Now, you rarely ever see the caterpillar itself.  It is rather small and looks like a
yellow-green to brown colored inch-worm.
 
The signs are ragged leaves that appear to have been chewed along with the black droppings.
 
My bougainvillea growing in the back garden.  I haven’t seen any signs of caterpillar damage yet.
 
If you see similar damage to your Bougainvillea, don’t panic.  Most Bougainvillea can handle the damage from the chewed leaves.
 
However, if your Bougainvillea is young, or if the infestation is severe, you can help to get rid of the caterpillars by spraying your bougainvillea with a product containing BT (bacillus thuringiensis), which is an organic pesticide.  I use Safer Brand 5163 Caterpillar Killer II Concentrate, 16 oz in my own garden.
 
In the case of my client’s bougainvillea, I told her that the damage was not severe enough to warrant any treatment.
 
Some of you may see similar damage to your yellow bells or orange jubilee shrubs, which I wrote about in a previous post, “Oh No, What’s Happened to My Shrubs”.
 
**In the future, I will be sharing some gardening problems or design challenges that I encounter during some of my consults and their solutions. 
 
 My hope is that they can help you in your own landscape 🙂
 
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I hope you have a great weekend.  We will be celebrating my 3-year old twin nephews birthday at our house tomorrow morning.  I’ll may post a picture or two next week from the party.
 
My daughter, Rachele, is doing well after the first week of her combat training in Mississippi.  But, she did share some funny stories that I will share with you next week too!

When I moved to the desert Southwest 27 years ago as a young bride, all I saw was a brown landscape, spiky cacti, landscapes covered in little bits of rock and very few trees.


If you had told me that you could grow any kind of fruit tree besides citrus – I would not have believed you.


Fast forward 27 years and I not only appreciate the unique beauty of the desert, but I have enjoyed my 4th annual apple harvest at the family farm.

Certain apple tree varieties grow very well in our climate.  (For information on what varieties do best, here is an earlier post I wrote about apple trees).


Summer is a busy time because of the different types of fruit there are to harvest.  Peach trees ripen first in late May followed by plums.  Early June is spent in the kitchen making peach and plum jams.


In mid-June, the apple trees are ready to be picked.

My daughter Gracie and I headed out to pick some apples.


When we got there, my mother was already busy picking apples and ‘Johnny’ my sister’s 3-legged dog was enjoying eating the fallen apples.


The trees had so many apples that the branches were hanging down under their weight.


Soda Pop, my sister other dog (and the daughter of my dog, Missy) was also enjoying a feast of apples.


Don’t they look delicious?

One of the apple trees had some trouble late last year with borers.  But we caught it early and got rid of them.

We hauled 3 huge bags of apples back home and I got ready to make some delicious things with them, which I’ll share with you next time.
*Below, is some helpful information regarding borers:

Adult borer beetles lay eggs in the crevices of the bark of apple trees – generally in the bottom 2 feet of the trunk.  The eggs hatch and the larvae tunnel their way into the trunk.


Signs of borers are small holes toward the bottom 2 feet of the trunk.  Sometimes you can sawdust poking out of the hole or even a little sap running down the trunk.

Prevention is the best treatment, but if you have apple borers there are a few things you can do:

– Take a wire (I recommend a wire coat hanger) and poke into the hole that the borer made and try to puncture the larvae.  Do this in the summer. You may have to work at this a little, but kids might have fun doing this 😉

– Paint the trunk with white latex pain.  This not only protects the trunk from sunburn, it also prevents borers from laying new eggs AND suffocates the borers already present.

If you have apple trees and want to help prevent borers away – plant cloves of garlic around your tree and let them grow.  Many apple growers report that the smell of garlic keeps the adult borer beetles away.  

By using garlic and painting the trunk of your apple trees, borers are more likely to stay away.

Most of my job as a horticulturist and garden writer is fun.  

But sometimes, I have to be the bearer of bad news.

Last week, I was called to a home where the homeowners were worried about one of their citrus trees.  Although I am a horticulturist, I am also a Certified Arborist, which can also be very helpful – especially when I am dealing with trees.

There was a large lemon tree in their front garden.  They were concerned because they had some branches dying back and wanted to know what the cause was.

So, I stopped by and took a look at the lemon tree.  At first glance, it looked fine – the homeowner had had the dead branches removed.

But, I had to look more closely, which meant getting close to the interior branches and the trunk.

What I saw in one of the remaining branches wasn’t good…

      
Can you see that the branch on the left is missing bark and is colored black?
What is this you may wonder?
Sooty Canker.
Sooty Canker is a fungal disease that infects many different species of trees including citrus.  It spreads through fungal spores.  The spores enter the tree through damaged areas on the branches or trunk, forming lesions and eventually causing the bark to peel off.
It is called ‘sooty canker’ because of the black color of the fungal spores.  The branches almost looked as if they have been scorched by fire.
In this case, the lemon tree had experienced severe frost damage 1 1/2 years ago.  Frost can cause splitting and other damage in the bark.  Sunburn damage can cause similar problems as wellThe fungal spores enter through these damaged areas and begin to grow.
If only branches are affected, they can be pruned 6 inches to 1 ft. below where you see evidence of the sooty canker.  Pruning tools must be disinfected with a 20% bleach solution to keep the disease from spreading between each pruning cut.
I was hopeful that I could tell the homeowners that all they had to do was to prune the affected branches.
But that was before I looked down at the trunk…
   
The entire trunk was infected with sooty canker.  Unfortunately, this almost certainly means that the tree will die.  
In this case, the tree should be removed to avoid spreading it to other trees.
I hated to tell the homeowners that they would have to have their tree taken out.  Especially after they told me how much fruit they had enjoyed over the years from this tree.
After I told them the fatal diagnosis of their lemon tree – I offered to look at their other four citrus trees.  I wanted to make sure that they weren’t infected as well.
Well, the good news was that their Meyer lemon tree was healthy.
The bad news was that their two orange trees and pommelo tree were all badly infected with sooty canker.  
Did I mention that I hate being the bearer of bad news?
I must say that the clients accepted the bad news very well.
In fact, they said that they had gotten tired of picking up dropped fruit AND that one of them couldn’t even eat citrus any more due to dietary constraints.
They will be removing their five infected citrus trees while keeping a close eye on their disease-free Meyer lemon tree.  At the first sign of a lesion, they will prune it away to help keep it safe from infection.
Guess what?   
They asked me to return in spring to design a new landscape area in place of their citrus trees.  I like being with people who see things as “a glass half-full”.  
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If you suspect that your tree has sooty canker – have a professional confirm the diagnosis and discuss with you the treatment options.  If the trunk is not affected, you may be able to save your tree. 
For more information, check out this link. 


*This blog post contains affiliate links. If you click through and make a purchase, I may receive a commission (at no additional cost to you). Thanks for your support in this way.*

Last week, as I walked out into the back garden, I noticed something that didn’t look right with my a few of my yellow bell shrubs (Tecoma stans stans)

The photo, above, shows how they should normally look, however, last week, they looked like this….

Definitely not normal looking and manyM of the outer leaves were skeletonized, and it got worse. All four of my yellow bell shrubs had the same symptoms.  So, did my orange jubilee shrubs, which are closely related.

To be honest, I was a bit stunned to see the damage.  You see, I had grown these beautiful shrubs for over 14 years and have never seen this before – not even in landscapes I managed or when consulting.

What was interesting is that other shrubs right next to my yellow bells and orange jubilee weren’t in the least bit affected. So, what is eating my leaves?

I looked at the symptoms – the skeletonized leaves, the fact that many of my leaves were ‘rolled’ and little black dots (insect poop) told me that my shrubs were suffering from ‘leaf rollers,’ which are tiny caterpillars that roll the leaf around them while they eat.  It is hard to spot the caterpillars themselves, but the damage they cause, usually makes it easy to diagnose.

Now that I noticed my yellow bells and orange jubilee shrubs being affected – I have noticed these same shrubs being affected in my neighborhood, along freeways and other areas.  I don’t know why leaf rollers are affecting these shrubs all of a sudden after all these years.  I suspect it is the higher than normal rainfall we experienced this summer, but I don’t know for certain.

Regardless of why leaf rollers are affecting these beautiful shrubs – there are ways to get rid of them. Here are a few different options:

1. Prune off the affected growth and dispose of the leave in the trash can (not in your compost pile).  

2. Treat your shrub using a biological pesticide that contains BT (Bacillus thuringiensis),  which is ingested by the caterpillars.  BT basically ‘eats’ its way from the caterpillar’s stomach outward. I use Safer Brand 5163 Caterpillar Killer II Concentrate, 16 oz.

3. You can use an insecticide spray to kill the leaf rollers.

4. Lastly, there are systemic insecticides that are applied around the plant and are taken up by the roots – but, their use can lead to the build-up of resistant insects and can have other negative environmental effects.

**Whenever using any pesticide – follow directions carefully. For my shrubs, I will prune back the damaged growth and not apply pesticides. However, if the leaf rollers continue to attack, then I may decide to use a product with BT.

So, if you have yellow bells or orange jubilee shrubs – check them to see if they are being affected by leaf rollers.


**If your bougainvillea leaves are showing signs of being chewed – they may have been visited by ‘bougainvillea looper caterpillars.’  For more information on how to recognize and treat these caterpillars, click here.
Thankfully, the rest of my garden is looking healthy 🙂