Tag Archive for: citrus trees

The Sunburn Experience: Not Just for Humans

Have you ever had a sunburn? Maybe a better question is, “Who hasn’t?”

Well, did you know that many plants get too much as well?

Sunburned Citrus: A Common Concern

On a recent visit to a client who was worried about her newly planted citrus trees.

new citrus trees planted in pots.

Sunburned Citrus

The Leaf Yellowing Dilemma on Citrus Trees

This particular client has a large courtyard with several new citrus trees in pots. Her citrus trees, planted in spring, showed yellowing as summer progressed.

sunburned citrus leaves

Now yellow leaves can indicate a number of different problems.  In this case, the diagnosis was rather simple – her citrus tree has a case of sunburn.

Common Signs of Sunburned Citrus and Other Plants

– The areas of the leaf that are yellow are in the center and NOT along the tips or edges.

– Often, the yellow areas begin to turn brown.

– Signs normally occur in the summer months.

– The sunburned leaves are usually located on the south and west-facing parts of the plant.

– This particular citrus tree is in an area that receives reflected, afternoon sun.

Citrus-tree-in-container-ASU


How to Prevent Sunburned Citrus

In this case, the solution is simple. Move the citrus tree to another part of the courtyard that receives afternoon shade is all that is needed to prevent further sunburn damage. Another choice is to put 50% shade cloth on from mid-May through September.

Citrus do best when planted at least 10 – 15 ft. away from walls. Unfortunately walls absorb the heat of the day and re-radiate it out.

Avoid planting where they get the full force of afternoon sun.

In honor of Halloween, I thought that I would do a ‘scary’ post for all of you.

Now, this post isn’t filled with ghouls, witches, skeletons or zombies. But that doesn’t make it any less scary.

Over the years, I have photographed examples of truly horrific pruning, which are quite scary 😉

WARNING:  The following images are not for the faint of heart…

horrific pruning

These used to be Jacaranda trees. I say “used to” because they died because of this severe and unnecessary pruning.

Red Yucca (Hesperaloe parviflora)

This is a photo of a Red Yucca (Hesperaloe parviflora) that was pruned the wrong way.

Unfortunately, this was a landscape that I was in charge of 14 years ago next to the clubhouse on a golf course.

My well-intentioned crew member, thought he was doing me a favor by pruning them for me. He was so proud of the work he had done, that he came into my office and asked me to come outside and see his handiwork.

I must say, that it was hard to criticize him because he was so proud of his work. Needless to say, I transferred him to doing more clean-up and less pruning around the golf course.

A few months later, he returned to his small town in Mexico where he became mayor 🙂

*This is what Red Yucca are supposed to look like when in flower…

horrific pruning

As you can see, you don’t cut the grass-like, succulent foliage below – ever. The flowers can be pruned to the base when they die. If the base clump become to wide, then divide the base much like you would perennials.

This photo was taken of another landscape area about 12 years ago that I was in charge of by another golf course. I made sure that the crew did not prune it 😉

horrific pruning

Last month, I was in the historic district of downtown Phoenix returning from a landscape consultation when I drove by these very sad California Fan Palms.

While fall is the time to prune back – this is NOT the way to do it. Too much was removed. For guidelines on how to prune palm trees, click here.

horrific pruning

This was a beautiful Palo Brea tree.  Unfortunately, it was ‘topped’ in order for the homeowner to preserve their view of the mountains.

‘Topping’ trees is very bad for trees. It leaves the upper branches open to sunburn, which is often followed by insect infestations or disease.

In fact, topping trees causes the tree to grow faster, to replace the lost foliage, which leads to an increased need for pruning. The branches that appear after ‘topping’ have a very weak attachment, which makes the new branches a hazard because they are in danger of breaking off.

**If a tree is blocking a view that is important to you – then remove the tree instead of subjecting it to torturing it with this type of pruning.

Acacia salicina

Here is another example of ‘topping’.  This parking lot in Scottsdale, has trees like this.

Believe it or not, this ‘topped’ tree is a Willow Acacia (Acacia salicina).

This is what it should look like…

horrific pruning

Hard to believe that they are the same type of tree, isn’t it?

agave

I don’t think that I have ever seen an agave pruned so badly before.

The only time you need to prune an agave is to remove the bottom leaves, once they die.

I think that this agave would have looked much nicer if they had left it alone, like the one below…

horrific pruning

It would also be much healthier and less likely to be susceptible to insect attack.

citrus trees

Believe it or not, these are citrus trees.

I could hardly believe my eyes when I drove by and saw what had happened to these trees.

You may be thinking that maybe they suffered from severe frost damage and had to be cut back. But, I assure you, this wasn’t the case. I worked just down the road from this house and there was no reason for these trees to be pruned this severely.

Ideally, citrus trees are pruned in March, concentrating on removing dead branches and suckers.

In fact, did you know that the lower branches produce more fruit that tastes sweeter than that on the higher branches? That is why you see citrus growers letting the lower branches of their trees grow instead of pruning them up into tree shapes.

**Just don’t let any branches (suckers) from below the bud union grow because they are from the root stock and are thorny and will produce sour fruit.

'Scary' Pruning Practices

Much like the Red Yucca I showed you earlier, these Desert Spoon have been butchered.

They also did the same to their own Red Yucca, off to the right.

Desert Spoon has a beautiful, natural form.

'Scary' Pruning Practices

The only pruning to be done is to remove the bottom leaves once they turn brown and die.

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I hope you haven’t been to ‘scared’ by these scary pruning practices.

Sometimes it is easy to get carried away when pruning. But it is important to remember that a plant’s leaves make the food for the plant. Take away the ability of the plant to make food, it will re-route resources normally used for dealing with environmental stresses as well as defenses against insects and disease toward growing new leaves.

This will make your plants/trees more susceptible to other problems, not to mention leaving them ugly.

“Scary” Pruning Practices and the Unfortunate Results