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Yellow leaves on Boxwood Beauty Natal Plum

Posted by senore100 AZ (My Page) on
Sat, Oct 23, 10 at 11:58

Hi everyone! I just signed up with this site, and this is my first post. Would like to thank you all in advance for any help!
We just got our front yard landscaping done three weeks ago. There are a few boxwood beauty natal plums. One of them has started to develop yellow leaves in the lower half of the branches and does not appear to be doing so well. Could anyone tell me what could possibly be causing this problem? Over-watering, fungus, or lack of certain nutrients? (Another one sitting a few feet away seems to be doing just fine)
Here's some background info. Since they were planted not long ago, we are watering the shrubs four times a day, 3 minutes each time. Since we use the adjustable emitters, natal plums are not getting a whole lot of water. Whenever there is rain, I shut the timers for 24 hours. This natal plum is getting a few hours of afternoon sun every day.
Thanks a lot!
Jeff


Follow-Up Postings:

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RE: Yellow leaves on Boxwood Beauty Natal Plum

You say that you are watering 4X a day? Do you mean 4X a week?
Nothing except newly seeded grass would need to be watered 4X a day.
Three minutes is not long enough. You want to water longer at shorter intervals. It's hard to say a time estimate because I don't know what your emitter output is.
Welcome to the forum!


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RE: Yellow leaves on Boxwood Beauty Natal Plum

Thanks for the reply!
It's 4 times a day. Yes. My landscaper told me that within a couple of weeks after planting we should switch a different schedule. Like you said, longer time once a day.
Now that it looks all the plants are still alive, maybe I should switch, plus the weather is appreciably cooling down.
What would be a roughly reasonable schedule like now?
Sorry for my ignorance but this is all new for me.
Thanks again!


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RE: Yellow leaves on Boxwood Beauty Natal Plum

Hi Senore,

The rule for watering here in the desert is 'deeply but infrequently'. Of course, when plants are newly installed they need more frequent watering to get their root systems going. Even so, I've never heard of watering 4x a day. As agilitymom says that schedule is used ONLY for germinating grass seed. (I hope you're not still using that same landscaper!)

You should only need to water your plants once every 4 or 5 days right now. The trick is to apply enough water so it soaks down for the entire root zone. For plants from one gallon containers that's at least one gallon of water. Plants from 5 gallon containers will need at least 3 - 4 gallons each time you irrigate.

When your adjustable emitters are fully open they dispense 10 gallons of water per hour. You'll need to dial these down so when you run your system they deliver the appropriate amount. Your goal should be to run your drip system for at least an hour, possibly two to deliver the correct amounts.

Our clay soils don't allow water to soak in at a very fast rate - that's why drip systems are so effective. They deliver the water slowly so it doesn't run off.

The symptoms you see on your natal plum could be from too much water - too often, which doesn't allow the soil to dry out a bit in between applications. Roots MUST have oxygen in order to pull nutrients from the soil. Too much water pushes out the oxygen and the plant basically suffocates.

You can learn more about drip irrigation from the free booklet - Landscape Watering By The Numbers. It's online at www.wateruseitwisely.com/arizona

Most of the cities in the valley have FREE landscape and irrigation classes. Just contact your local water conservation office.

Here's a link to information on watering landscapes. Scroll to the bottom of the page and you'll see a table for newly installed plants.

Good luck!

Here is a link that might be useful: Landscape Watering Guidelines


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RE: Yellow leaves on Boxwood Beauty Natal Plum

Aztreelvr,thanks so much for your kind reply! I really appreciate it.
The shrubs and the lawn seem to have been established -- they are still alive, and I've just changed the watering schedule. Right now I am watering my lawn once a day (10 min), and my shrubs (with emitters half open) and trees (with emitters fully open) once every three days (10 min -- there are three emitters on each tree).
I've been searching online and have also talked to a gardening expert working at Lowe's. Unfortunately what I've got oftentimes is conflicting information. The schedule I am following now is based on information I got from the expert at Lowe's. As you can see, there is a huge discrepancy between this schedule and what is given at the chandleraz.gov. That's why I am still lost -- the expert at Lowe's told me that if I don't water my lawn every day, it will die. That's why I would like to ask around on this forum and see what everyone is doing.
Thanks again!


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RE: Yellow leaves on Boxwood Beauty Natal Plum

I think landscapers often tell you to water too little too often. Most people seem to do this.

When I moved to my house they were watering trees and bushes alittle every day.

My drip line for plants was not working most of the summer and although I watered some things more, I was surprised at how well some bushes and plants did with out much watering but good deep watering with time to dry out.
You may have to experiment a bit, just keep a close eye on things.


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RE: Yellow leaves on Boxwood Beauty Natal Plum

Senore,

You could ask 5 different people how to water and get 5 different answers. The information I gave you is based on research by the University of Arizona. Unfortunately, the folks at the big box stores aren't necessarily experts in horticulture. Instead they may be transferred from the plumbing section or lumber area.

NEVER water your lawn every day. Bermuda grass thrives in an arid climate. It can survive for months with no water all and come back green and vibrant after a good soaking. The only exception would be if you were starting a new lawn from seed or sod.

Watering for short periods every day doesn't encourage the roots to grow deeply into the soil. Deep roots equals strong grass. If you haven't overseeded you lawn for the winter, your Bermuda grass only needs to be watered once a week right now. BUT the water should soak down to 6-8 inches in the soil. You can check this by using a screwdriver. Push the driver into your lawn in several places. You should be able to easily push through the soil where it is moist. If you can't push further than 2 - 3 inches you need to water your grass longer (but not more often). If you allow your lawn to go dormant for the winter water it once a month - unless we get good soaking rain.

For your landscape plants think of it this way. One gallon of water will moisten 1 cubic foot of soil. Right now you are applying about .83 gallons to your shrubs (assuming one emitter on each) and 5 gallons to your trees (three emitters at 10 gallons/hr. for 10 minutes).

This time of year your trees and shrubs only need water once a week. By January 1 they will only need water once every 10 days. If you have palo verde, mesquite, sissoo, evergreen elm or other desert adapted trees, they need water even less frequently (once every 2 weeks now - once a month in Dec/Jan/Feb).

I'd be happy to chat 'off forum' if you want to send me an email.

aztreelvr
certified arborist
certified landscape irrigation auditor
master gardener

Here is a link that might be useful: Free landscape publications to view or download


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RE: Yellow leaves on Boxwood Beauty Natal Plum

Thanks to both dchris and aztreelvr! So I'm not the only one who has been encouraged to water more frequently than necessary!
I am totally amazed at the difference in water usage between what I've been told and what you and those online resources that you gave suggested. I just started trying watering less frequently but deeply!
About two weeks ago, actually there was quite a bit of rainfall in Chandler, and I left the timer turned off for about a week. The grass, shrubs, and trees were still alive!
One thing I've noticed is that every time after watering the shrubs, the soil under the gravel remains wet for days and days even when I leave the timer off (I can even see there are patches of gravels that appear wet all the time). Does this suggest that there may well be a drainage problem or there could be leaks from the dripping system here and there? Thanks again for all the help!


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RE: Yellow leaves on Boxwood Beauty Natal Plum

Senore,

Our soil here in the Phoenix area (and many other low desert places) has a high clay content. Clay holds LOTS of water and dries out slowly. That's why we preach 'deep and infrequent'. What you are seeing is the moisture being pulled to the top of the soil by evaporation. It's most evident in the morning and by afternoon many times the soil on top is dried so you don't see any indication of moisture below.

Each time you irrigate the water soaks down to a particular level in the soil. Then evaporation pulls it back to the surface by capillary action. The longer you can keep the moisture in the root zone (by watering deeply) the less often you have to apply water. Plus it encourages deep roots which anchor the plants securely. Deep roots are insulated by extremes of temperature, especially our scorching summer heat. Deep roots help keep plants healtahy and allow them to survive during times of high heat, low humidity, blustery winds, freezing nights, etc.

You could have leaks in your drip system - it's pretty common. Just walk your landscape while your system is running and watch for pooling water, little geysers where emitters might be missing, or even hissing sounds where water might be flowing under a shrub or gravel.

Drainage could be an issue too. Many homes are built on old agricultural areas that tend to have a compacted layer at about 2 - 3 feet down. This corresponds to the depth of the tines of the machinery that tilled the fields reached. Plus, during construction dozens of vehicles ran over your property further compacting the soil. I wouldn't worry too much unless you have water sitting on top of the soil that doesn't drain within 24 hours.


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RE: Yellow leaves on Boxwood Beauty Natal Plum

Thanks so much aztreelvr! Now I feel much better now. I was really worried there could be some serious leaking in the drip system. Based on your post, there does not appear to be such a problem. And now I understand why the soil below the gravel is damp. Just the day before yesterday I planted a 7 gallon pygmy palm myself. I dug a whole a little more than a foot deep, and there was plenty of moisture in there.
Still playing around with the watering schedule, reducing the frequency while extending the length each time, keeping a close eye on how everything is going.
I read online the other day that Phoenix is number 2 on the list of cities where water is an endangered resource. And a lot of people in the area are probably unnecessarily over-watering every day! Hope more people come to this forum and get what they need!
Thanks for all the help and your kindness. I really appreciate it!


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