Xtremehorticulture

Late Application of Iron Fails to Cure Yellowing

Kerex iron application made to the soil after growth has already begun will result in yellow leaves on the older leaves while the new leaves coming out after the application will be green.

Q. I have a Burgundy plum tree that is 3 years old. The
leaves became yellow in March so I applied Kerex iron to the soil when I first
noticed the problem. Now the new leaves do not show any yellow in them but
older leaves are still yellow so I do not think it is an iron problem.

A. Iron does not move once inside the plant. It is still an iron issue. You said the NEW leaves do
not show any yellow. That means your KeRex application in March worked for the
leaves which grew after your application.

Iron does not move around inside
the tree once the plant takes it up, it only goes into the new growth after the
application is made.We say that iron is immobile once inside the plant. It is not like nitrogen which can move from older leaves to newer leaves. Iron cannot do this. Iron can only be transported into new growth. Growth before the application will still stay yellow.

Correcting the problem. The only way to correct yellow of older leaves is with iron spray applied to the leaves. This is why SOIL applications of iron are so important to make in January before growth occurs.

An example of an iron product that can be used for foliar applications, or sprayed on the leaves. Spraying the leaves with an iron solution is the only way to correct yellowing once it is already started. Make sure you use a wetting agent mixed with the iron spray.
EZ Wet is one example of a high quality wetting agent that does not contain
any personal care products and made entirely from yucca extract.

It is not too hot too late to
spray iron on the leaves. It may take four or five sprays a couple of days
apart to get all the yellow leaves completely green.


Any iron product, labeled as a
spray applied to the foliage of fruit trees will work. However, I would
strongly suggest that any water mixed with this iron fertilizer should be
distilled water so that the pH is close to neutral (pH of 7).

Alternatively,
you can adjust the tap water close to neutral using vinegar or another mild
acid as well.


You should add a wetting agent
to the spray as well. This helps the iron penetrate the leaf surface and enter
the inside the leaf. Otherwise the spray is not as effective. Some people use
liquid detergents with good success. I worry a little bit about the other
personal care products in liquid detergents so I would encourage you to use a
commercial wetting agent.

If you are still unsure how to
do this, you can read more about how to do this on my blog or email me at [email protected]

5 thoughts on “Late Application of Iron Fails to Cure Yellowing”

  1. One of the best wetting agents is derived from saponins. This is why I like EZ Wet. The only place I know to get it in Las Vegas is from Viragrow in North Las Vegas. http://www.viragrow.com It is retailing for $17 a quart I believe. Without reading the label it will treat from 30 to 50 gallons of water.

  2. One of the best wetting agents is derived from saponins. This is why I like EZ Wet. The only place I know to get it in Las Vegas is from Viragrow in North Las Vegas. http://www.viragrow.com It is retailing for $17 a quart I believe. Without reading the label it will treat from 30 to 50 gallons of water.

  3. One of the best wetting agents is derived from saponins. This is why I like EZ Wet. The only place I know to get it in Las Vegas is from Viragrow in North Las Vegas. http://www.viragrow.com It is retailing for $17 a quart I believe. Without reading the label it will treat from 30 to 50 gallons of water.

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