The dirty truth about yellowing leaves when Fall hasn’t even arrived

chlorosis shrub leaves

It is a subtle change but one day you notice that the leaves on one of your shrubs (or maybe a tree) are turning yellowish and as far as you know yellow leaves are not natural to this plant–even in Fall. You look closer and see that the veins in the leaves are still green as you can see in this photo.

Well, what you are looking at is chlorosis, a kind of iron-deficiency in plants that inhibits the development of chlorophyll, the stuff that makes green plants green and keeps them alive and growing.  It is most common in plants grown in alkaline soils with high pH.

The problem begins in the dirt, the soil in your garden.  Even in hot dry desert-like gardens there is ample iron in the soil, but unfortunately plants can’t access it. The technical causes for the iron/soil problems read like a chemistry textbook so I will skip it, but advise you to take steps to reverse the condition before it gets worse. After all, you don’t want to lose an expensive plant or tree, especially to a plant problem that is curable.

What you need to do at this time of year is apply a foliar spray of iron chelate (pronounced “key-late”) to the leaves of your plant. It is available online and probably at a local big box gardening or hardware store for less than $15. It may take repeated applications of the spray to green up your shrub again.

But even a foliar spray is a temporary solution, effective for two or three months.

The next steps are to

  • Test the pH of the soil around the plant with chlorosis using an inexpensive pH testing kit which you can easily find online.  You may want to test other parts of your garden too.  (In fact, you may want to check the pH every year!)
  • Add chelated-iron fertilizer to the soil around the plant or tree IN SPRINGTIME (not Fall).  This is a longer term solution than the foliar leaf spray.
  • Dig in extra amounts of organic materials in the Fall and the Spring to balance the soil in your plant beds to a neutral 7 pH.  If you can get it to 6.5, all the better. Plants love 6.5 pH!  Keeping a high level of organic materials in and around the plants is a long term solution to chlorosis.
Rio Grande Fax Tex Ash autumn

BTW, if you have a Fan Tex Ash tree the leaves on it will naturally turn yellow in Fall. It is one of the very few trees for hot dry gardens that has lovely Fall color. (Of course, there are the aspen trees that grow in the mountains around the deserts and also become golden in Fall.)


CLIMATE CHANGE UPDATE

In an abrupt about-face the Australians tossed out their Prime Minister who announced last week that keeping fuel prices low was more important than meeting Paris Accord climate change limits. Among the first things the new PM stated was that climate change came first–particularly in light of the severe drought that is impacting ranchers in New South Wales, outside of Sydney.


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Best fruit to plant in a hot, dry desert-like garden

pomegranate fruit on bush (

Shortly after moving to Las Vegas back in the 1990s I went on a hike with the Sierra Club in what is now the Red Rock  Canyon National Conservation Area. Our destination on this hike was an old abandoned ranch about 3+ miles from the pull-out on Highway 159 where we parked our cars. The ranch owners had walked away from the ranch years ago and turned it over to the Bureau of Land Management. (And the BLM had pretty much just ignored the place.)

So about 10 of us tromped off across the wide canyon floor. As a newcomer to desert hiking I forgot to bring water and it turned out there was no water at this old ranch. Just a weather-beaten house, a couple of fences that tilted and sagged…AND a row of pomegranate bushes still producing big red pomegranate fruit. These 8-10 foot high shrubs had survived for years with only the water that fell from the sky. And in Las Vegas, the average annual rainfall is about 4 inches! It might be a bit higher up in Red Rock Canyon, but not by much.

This was evidence that pomegranates grow well even under very dry conditions. And if you add a little bit of care and water they will do even better. Another plus: the leaves turn a lovely yellow in Fall and at Christmas time the fruit–if you haven’t picked it–looks like red ornaments in your garden.

So if you want a low-water usage fruit to harvest from your own backyard, plant a pomegranate. The ‘Wonderful” variety is an excellent choice and will do well even with neglect.

But don’t neglect taking water with you on a desert hike. I have always had water with me ever since that day.

Las Vegas Red Rock canyon (
This view is from the pull-out where we parked our cars. The abandoned ranch where the pomegranates were growing is up against those mountains.

See more suggestions about fruit trees for hot dry gardens.


Our 8 most popular newsletters

  1. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting