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Each time I go on a landscape consult, it is an adventure.  I never know what to expect.   Will there be serious problems with any of the trees and plants?  Or will my help be needed to re-design the landscape, adjust the irrigation schedule or help people learn how to maintain their plants?  Well, life is full of surprises. 

Of course, every time I go on a consult, I always bring my camera.  I am always looking for examples of beautiful plants and problems to photograph.  I then share many of them with you.


Yesterday, was a gorgeous spring day.  The high was 78 degrees and I actually had two consults scheduled, within two miles of each other.  My first client had just bought a new home and wanted help identifying her plants and how to take care of them.  She also had inherited some sick citrus trees and needed help in how to help them.

First the good things that I saw….


I was greeted by the front entry by this spectacular white flower.  Argentine Giant (Trichocereus candicans), is a cactus that is highly desired.  It produces flowers a few times during spring and summer months.  This particular cactus was absolutely covered in these large blossoms.


Nearby the Argentine Giant, was the smaller Claret Cup Cactus (Echinocereus triglochidiatus) awash in bright orange blooms.


An unusually shaped flowering Twin Flower Agave (Agave geminiflora) caught my eye.  Normally, they produce a single flowering stalk like the one on the left.  However, the one on the right had seven smaller stalks.  I love seeing examples of plants that are doing something out of the ordinary 🙂

Now for the bad….


This is one of the four sickly citrus trees that I was asked to see.  The diagnosis was relatively easy.  Lack of water and nutrient deficiency.  Both problems will be solved by enlarging the basin underneath the tree so that it extends out to where the branches end.  As the tree grows, so must the basin since a trees roots extend outwards where the branches extend.  A new watering schedule and making sure that the water penetrates to 3 ft. in depth should do much to help these trees.

Nutrient deficiencies are corrected by fertilizing citrus trees three times a year – in Feb/Mar, May and September, using either a synthetic or organic fertilizer specially formulated for citrus which contains not only nitrogen, but also micronutrients that are often deficient in our soils.  
More information on citrus care, irrigation and fertilization can be found here.


As I walked the landscape with the homeowner, we started looking at the trees that she had inherited with her new home.  I quickly noticed something very bad.  The previous homeowners had never removed the stake and cables from their tree when it was young.  
The tree ended up growing around the wire and there is no way to remove it now without seriously damaging the tree.  Usually, when wires are left on the tree, they gradually cut off the nutrients to the tree as the “veins” of the tree are located directly underneath the bark.  This usually results in the death of the tree.  However, this Mesquite tree appears to have survived and regrown it’s vascular (veins) system around the wire.  The tree is 11 years old and is the exception in terms of surviving this type of treatment.  


**If your trees are staked, PLEASE make sure to check your wires/cables to make sure that this does not happen to you.  Trees are not to be staked forever, only the first 1 – 2 years after planting.


Now the next bad thing I observed was not immediately obvious, but as I began to focus my gaze upwards to evaluate the trees, I saw a few clumps of mistletoe (Phoradendron californicum) growing in the tree.  Now, this is not the same kind of leafy mistletoe that is often seen at Christmas.  But it is a parasite that will, over time, cause a decline in the tree and stress the tree.  This makes the tree more susceptible to disease, insect infestations and other stresses. 

As an arborist, I have taken part in discussions regarding whether or not you should leave mistletoe in trees.  Mistletoe is part of the natural desert and can be seen growing in trees in the wild. Mistletoe itself will not kill a tree, but does stress the tree and leaves it vulnerable to disease, insects and environmental stresses that will kill the tree eventually.  
 In managed landscape areas I have always had mistletoe removed.  In my opinion, trees do not need any additional stress and the trees are part of a larger landscape design and aesthetics are important.  

I also recommend that homeowners also remove the mistletoe from their trees.  Not only will it help their tree, but will help keep the mistletoe from spreading to their neighbor’s trees.  Mistletoe is spread when birds eat the berries it produces and then they ‘poop’ them out on another tree’s branch and the seed germinates and starts to infect the branch it landed on.


Small clumps of mistletoe are not always obvious, but once you know what to look for, you will easily be able to spot it.  I recommend looking at your tree in the winter, when there are fewer leaves to hide the mistletoe.

There are two ways to remove mistletoe.  To completely get rid of it, you need to cut the branch that it occurs on at least 12″ below where the mistletoe begins.  In most cases, this will completely get rid of the mistletoe.  This works best with smaller branches.  However, if you have a very large branch that is infected, it may not be feasible to remove the branch.  In this case, you can prune the mistletoe off – just take your gloved hand and brush them off of the branch.  It is really that easy.  Doing this will not get rid of the mistletoe, but help to control it.  You will have to continue to do this periodically to keep the mistletoe from becoming larger and spreading.


Now on to my second client of the day.  Overall, is landscape was in good shape.  His citrus trees were healthy as were the rest of his plants.  But, the majority of his concerns were in regards to his irrigation system.  His mature Palo Brea tree (Parkinsonia praecox), pictured above, still had the irrigation emitters positioned by the trunk of the tree.  The same place that they had been place 8 years ago.  The problem is, the roots have now moved.

I explained to him that as a tree grows, so do the roots.  They grow outwards, toward the edge of where the branches extend.  And so as the tree grows, the emitters need to be moved and places around the tree where the branches end.  For this tree, three 2 (gph) emitters evenly spaced around the tree will work just fine.

Well, I had a very fulfilling day working with some very nice people.  I just love help people learn how to care for their trees and plants and spend time outdoors and admiring the beauty in people’s gardens.

As I was leaving, I saw something very ugly….
This homeowner had ‘topped’ his Mesquite tree.  Now, I am not sure why they had this done.  I could tell that from looking at the branches, that it was not the first time it had been ‘topped’.
Now any arborist will tell you that ‘topping’ is bad and there are a number of reasons why.  I will address it further in another post, but will leave you with these few reasons NOT to top your trees:

-It causes the tree to grow more quickly to replace the leaves lost, therefore increasing the amount of pruning needed.
-The new branches will not be firmly attached and will be more likely to break.
-Topping stresses the tree, making it susceptible to disease, insects and environmental stresses.
-If those reasons are not enough, then maybe this one will be….IT IS UGLY.
*For more information on the damage ‘topping’ trees does, you can visit The International Society of Arboriculture.
Thank you for hanging in there with me…I realize this was a long post, but there was so much to ‘talk’ about from my visits yesterday.  I hope you enjoyed the beauty of the flowers and that maybe I have helped people avoid some of the problems that I have highlighted.

 Did you know that just by making one change in your garden that you will benefit not only the earth, but also your plants, your back and your pocketbook?  The one change I am talking about is making sure that you are watering your plants at the recommended rate for your area. 

Okay, first the benefits to the earth.  The first one is fairly obvious….by watering at the proper rate and frequency, we are conserving water – a precious resource.

Now the first benefit is fairly obvious, but here is another one….did you know that when plants are watered correctly, that they produce less excess growth and grow at a healthier rate?  Many of us do not take that into consideration or even think of it. 

Each time I consult with a homeowner, I often go over what their current irrigation schedule is.  Believe it or not, over 90% of the time, I find that their trees and plans are being over-watered.  In fact, one of my horticulture professors did a study and found the same statistics.  Naturally, that is understandable; we live in a desert, so logically we think that more water will help our plants.  

But, the truth is, is that the majority of plant problems we see related to irrigation is due to over-watering NOT under-watering.  


Mature shrubs and trees need less water then you may think – especially if you are growing plants that are adapted to our arid-climate.  In response to over-watering, the extra growth that is produced has another interesting effect….it causes the plant to use more water in order to maintain the excess growth then the same type of plant being watered at the proper rate.

Irrigating (watering) correctly not only causes your plants to grow at a healthy rate, but also encourages roots to grow deeper where the soil is cooler and moister and helps to flush out salts in our soils that can build-up around the roots of your plants.  As a result, your plants will be better able to withstand the stress of summer.

Here is an example for our area (around Phoenix): Did you know that your mature citrus trees only need to be watered every 21 – 30 days in the winter and every 7 – 10 days in the summer?  The past three clients I consulted with, who had citrus trees, were watering them 3 times a week in the middle of winter.  They were not watering them long enough and not deeply enough.  Many of their trees were suffering multiple problems related incorrect irrigation, which were easily corrected by changing their watering schedule.

Okay, you may be saying, I don’t have any citrus, so how does this apply to me?  Well then, here is another example; desert-adapted shrubs need water every 7 – 10 days in the summer.   Even mature shrubs that are high-water use only need water every 5 – 7 days in the summer.   Most people are watering their shrubs every 2 – 3 days in the summer.  *I water my own shrubs every 7 – 10 days throughout the summer and once every month in the winter and my garden is thriving.

Now, for the savings….you do the math – with less growth, there is less pruning required and therefore less maintenance.    So, we are not only conserving water and saving $ off of our water bill, but also using up less space in the landfill and also saving you money (if you use a landscape company to prune your trees and shrubs).   Or at the very least, saving you a backache from all of that extra pruning you are saved from doing ;^)
All right, you are saying, that sounds great….save the earth, healthy plants, less pruning and saving money – all good things –  I’m on board, but what do I need to do to get started?  
 

Okay, here are the keys to watering your plants the right way – it all has to do with how deeply your plants are watered and the frequency.  Trees should be watered to a depth of 3 ft. and shrubs to a depth of 18 – 24 inches.  The trick is, figuring out how long you need to water each time to reach the recommended depth.

 The length of time for each irrigation cycle can vary depending on your individual system.  So, to do this, all you need is a 3 ft. piece of rebar, (seriously, that is it).  Once you have irrigated (watered) your plants, gently push the rebar down to see how far the water has penetrated.   It will slide easily down through the moist soil.  When it stops, measure the distance on the rebar to see how far it penetrated and you can see how much longer or shorter a time you will still need to water.

*The average time the water should be turned on for shrubs is approximately 2 hours at a time, but this can vary depending on your irrigation system and soils.


Adjust how often your water (the frequency), seasonally.  Plants do not require the same amounts of water in winter then the rest of the seasons.  However, the length of time you turn on the water does not change.  

Even though the specific recommendations of this post are geared for the desert gardener in Arizona, the broader principles can apply to us all.  For those of you who do need to provide supplemental water to your plants, take the time to make sure that you are watering them correctly. 

 I would like to offer one word of caution, when changing your current irrigation schedule, gradually wean your plants from the excess water they have been receiving – you don’t want to shock your plants and it will take them some time to adjust to the longer length of time between each watering cycle.  

I am joining with Jan from Thanks For Today and other fellow garden bloggers in sharing ways to garden sustainably in honor of Earth Day and this is my submission :^)  Please visit her blog to see links to other posts honoring Earth Day.

 


*For landscape watering guidelines in greater Phoenix area, please visit AMWUA which is an excellent resource on irrigation which has more specific information on how often to water seasonally.


*For guidelines for watering citrus, please check out the following link.
 Community Center landscape which I was honored to have designed along with renown landscape architect, Carl Johnson.
This past weekend, I participated in a landscape discussion panel as part of a “Living Green in the Desert” seminar.  Attendees were able to submit their questions ahead of time as well as ask their questions directly to us.
 
Golf Course Feature Area with Bougainvillea, Gold Lantana and Purple Lilac Vine grown as a groundcover (2002).
I was looking forward to being a part of this seminar because I had worked in this community for over 5 years as a horticulturist.  So I arrived early and drove around the community and golf course areas looking at the areas that I had designed and planted over 7 years ago.
Plants that I had set out ready for the crew to come and plant (2005).

I look at the landscape areas as old friends.  Of course, as living things often do, many had changed.  Some areas had matured and the small plants that I had set out had matured into beautiful specimen plants.  Other areas looked a little bare since flowering perennials had not been replaced, but the areas were well-maintained.
Desert Marigold, Firecracker Penstemon, Eremophila Valentine and Desert Spoon were planted in this feature area (2002).
   There were 3 of us on the desert landscape panel.  Although I knew one of the other participants, I always enjoy the instant camaraderie that occurs between fellow landscape professionals.

We had three different landscape sessions and the focus was on ‘living green’ in the desert landscape but all gardening questions were welcomed. 

This feature area consists of only succulents such as Soaptree Yucca, Purple Prickly Pear, Desert Spoon, Opuntia robusta, Agave colorata among others.  There is no regular irrigation in this area.  We hand-watered the cactus monthly during the first two summers until they were established.

There were some excellent questions, and I will highlight the most popular ones.

Question #1- When and how do we prune our shrubs.  Are they supposed to look like ‘balls’?

There is an epidemic in the Arizona desert where desert shrubs are pruned into round ball shapes, or as we in the landscape industry refer to as “poodle or cupcake” pruning.  Those of you who have been reading my blog for awhile have seen me get up on my “high-horse” more then once, and rail against this practice.  I will not repeat myself here, but you can read my previous post where I dealt with this unfortunate practice – Shrubs Aren’t Meant To Be Cupcakes. 

This was my favorite part of my job; designing new landscapes and seeing it all come together.  
Although the plants are very small when first planted, they grow very quickly in our climate.

Question #2 – When should I fertilize my plants?

Actually, most of your arid-adapted plants do not need to be fertilized.  I only fertilize my plants if they show signs of a nutrient deficiency.  We do fertilize our container plantings and fruit trees.  Compost can be applied to all plants as this ‘feeds’ the soil.

Purple Trailing Lantana, Mexican Bird-of-Paradise, Parry’s Penstemon, Desert Spoon and Angelita Daisy brighten the entrance to the clubhouse (2005).

Question #3 – Is it possible to have plants in my landscape that do not require any water?

 The answer is yes you can if you use native plants.  But, you will have to water them until they become established.  Keep in mind that all native plants will look much better when watered periodically.  That is what is done to the plants at the Desert Botanical Garden

For excellent guidelines as to how long and often you should water your plants, please check out this excellent site, which has information about irrigating your plants in the Arizona desert, including a schedule you can put in your irrigation controller – Landscape Watering Guide

The native plants were watered in this area monthly until they were established.  Periodic water was supplied during the summer months (2005).

 Question #4 – Is it possible to have a winter landscape with flowering plants?

The answer is absolutely! Many residents of this community are winter visitors and are away in the summer when most plants are flowering.   You can read more in a previous post of what types of plants flower during the winter months – Colorless Winter Garden…No Way! 

This area was planted with Eremophila Valentine and Cassia shrubs.

Question #5 – How often do I need to water my citrus trees?  They are currently being watered twice a week. 

  When I am asked to consult with a homeowner regarding their landscape, over 90% are watering their citrus too frequently and not deeply enough.  For example, in the winter months, citrus trees should only be watered once every 3 – 4 weeks.  Many were shocked.  I will cover citrus irrigation in more detail in the future, but there is excellent information which can be found here –  Citrus Irrigation Guidelines.

One of my favorite views from the golf course.

I had a wonderful day and enjoyed seeing old friends and meeting new ones.  I was able to spend the day doing one of my most favorite things –  help people learn how easy it is to have a beautiful, low-maintenance garden in the desert using plants that thrive in our climate.
Gardening in the desert is not difficult, it is just different….