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Monday, August 13, 2012

Yellowing of Meyer Lemon Tree Leaves Hard to Correct


Q. We went and talked to nursery folks a couple times about this tree. First we got the water cycle correct, then iron was suggested which we did as directed. Then a soil amendment was suggested. Online I read possibly the tree suffers from a magnesium issue. I thought these photos would give a better picture. We did as directed and the tree is not responding in fact it is getting worse. I am wondering if it is because of where it was planted which is a confined root growing area. Any insight would be appreciated.

Readers lemon tree with yellowing leaves
A. By looking at the leaves I have to assume this is a Meyer Lemon (which is, by the way not technically a lemon but an unknown hybrid found in a Chinese back yard by USDA researcher D. Meyer in the early 20th century).

Your pictures are all pretty good with the exception of not showing a critical view of the trunk where it is just out of the soil. Just for future reference always look at and show this interface of the trunk and soil. W/o that view I have to only guess that the rootstock/trunk union is well out of the soil and we can eliminate that issue. And, a shot of the soil might show how the plant is getting watered. I have to assume drippers and I would guess they are in the same locations as when the plant was planted.

Closer look at readers yellowing leaves
The leaves show two distinctive symptoms that often occur in concert: 1. There is some salt burn and 2. The common symptom that comes with salt issues is the magnesium deficiency. Just FYI Iron deficiency only occurs on the new leaves.
For the salinity (salt) issue we usually look first at the watering and with watering comes knowing if the water can even be applied uniformly all around the edge of the canopy, sometimes called the 'drip line'.

Citrus are botanically a shrub with shallow and wide spreading roots that are tough to grow to maturity with drippers unless they are closely spaced in a wide band around the canopy's edge. There is one picture showing the plant is right next to a step wall with no water being applied in that zone of the root system.

Clear look at the yellowing or chlorosis problem
on readers citrus
I would not worry too much about adding any supplements and see if you can begin to manage a watering system of application that would give a long deep soaking water application out near the drip line. The 'soaker' hoses could be laid out on the ground out near the drip line and let it run for hours and hours to try and leach out the excess salts that may have accumulated over time with the drip system. Drip systems are fine but, due to their limited water output salts can begin to accumulate thus impacting citrus' sensitivity to salts.

Give it a long deep watering about once every few weeks from now on all during the growing season (May through October)  to supplement the regular water to leach out the salts that inevitably are deposited with the limited volume of drip systems . .This leaching watering is also the great time to add fertilizer and get it into the soil evenly all around the active roots near the drip line.
-Terry Mikel

7 comments:

  1. I have a dwarf Myers lemon and this is it's 3'd year of growth and second season of producing. The first crop last year was 11 lemons which reached full maturity. The second crop which had a tremendous flush of blossoms (over 500) and after the "june drop" I know have approx 35 lemons in various stages of developement. I have noticed that my leaves are turning yellow. The container is 18 dia and has a water saucer below to hold water. The tree is next to a Key Lime and a Veneous Orange tree, both in identical planters. I fertilize with Miracle Grow Citrus pellets and water it consistently. Both the Key Lime (has approx 100 key limes developing) and orange tree (not producing yet) have beautiful lush green leaves and my poor lemon tree looks like it's struggling. It's planted with the roots right below the soil line and the trunk above. I do not think it's a water issue (we are on well water and mother nature)and the fertilizer I am using has Magnesium and iron. Any idea what my problem might be. It has new growth but the new leaves are showing the veins pretty prominately and are not nearly as green as the other citrus trees.
    thanks for you help.

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    1. Send me some pictures at Extremehort@aol.com

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  2. Another possibility is yellowing due to high light intensity. This is more of a "bronzing" color and discolors the entire leaf. Iron is pretty distinctive as it happens on newer leaves or is progressively more yellow on newer leaves and typically in the early stages the veins remain more green while the spaces between the veins are yellow or a lighter green in early stages. Just because you add iron or have iron in a fertilizer does not mean it will work. Iron chelate fertilizers are your best choice to use for iron fertilizers. In particular, iron in the form of EDDHA chelate is the best. As a regular course of action I would get some iron EDDHA chelate fertilizer and add it into your fertilizer program once a year as a precaution. It is hard to find everywhere in Las Vegas. Plant World nursery does carry it in one pound cannisters. The other places have not carried it in the past. If it is this bronzing/yellow discoloration then there is not much you can do the leaves already discolored. But move the plant out of an area with high light intensity all day long.

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    1. I have a Meyer lemon thats in a huge container and i've had it about 3years it was given to me as a present it had scales the second year i had it and i cleaned them off hoping to keep them contained but now it has yellowing around the leave edges and i feed it with miracle grow once this year don't know how often to but don't know what to do with the yellowing edges of the leaves and it hasn't blossomed this year ethier and i'm not computer literate enough to send picture its about 2ft tall in the container and just don't know what to do. I had one before and for the longest time in my greenhouse and it finally died and was told i needed to keep it outside so i have this on my porch in a container as i had my last in the greenhouse can you help i hope

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  3. Scale insects on citrus is usually controlled with some sort of oil application either during the winter months or spring and fall. As the name suggests, scale insects cover themselves with this hard outer shell while they're feeding on plant juices. They come out of the shell to mate and lay eggs. The eggs hatch, these younguns find their own place to start sucking plant juices and surround themselves with this hard scale. So the only time to really get them is when they come out of that scale to mate and lay eggs. Problem is we don't know when this is. So we apply dormant oils or summer oils such as Volck Supreme during the winter, spring and fall months. We normally avoid the hot summer months when we apply summer oils or you can get leaf drop and plant damage. The oil acts like a blanket on these insects when they are not protected by the scale and suffocate them. Regarding the yellowing I would look at the previous posting about iron EDDHA and apply that. Otherwise during the growing season and when there is no fruit present that could get stained, apply a liquid iron to the foliage and use a wetting agent such as Ivory liquid or a commercial wetting agent.

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  4. It is too hot there - nothing more. You are getting a huge reflection of heat from the walls - if you have an infrared thermometer it is probably going to read very high. There isn't too much wind circulation either by the looks of it. Plus, those roots are in contact with all sorts of nasty things the construction people bury close to the house when they build it. If you aren't watering deeply but infrequently, your roots are also too close to the surface. This happens a lot when drip systems are used but the perimeter isn't extended as the roots grow outward. Watering every week, once, overnight is better for trees of any kind in the desert - it creates a situation where they will keep sending their roots farther down into the soil and it will create a more drought proof tree as well as a healthier tree. I keep all citrus under 70% shade in the summer. Everything needs to be mulched with straw or hay - the sun is baking everything to death.

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  5. I have 4 or 5 year old meyers lemon, in Indiana. Given to me as a gift last summer. put on many blooms this summer and set fruit. i pinched off all but one lemon per limb. That's probably more than they can support. Planted in a large fabric container. leaves started yellowing about three months ago during middle of summer. Fruit is increasing in size 9near golf ball size) but tree looks like it on it's last leg. A few leaves have competely died 9 three or 4) and fallen off. Had to bring them all inside two weeks ago when outside temp's dropped below 40 degrees. Have a Satsuma Orange (too young to bear on one side and a kumquat on the othe side loadred with, pencil side fruit. All three on the same fertilizer (mostly organic), watering schedule. Orange and kumquat appeasr in excellent health. Now that they are inside they have a large south facing window with supplimental HID. Have them on a cart so when temp is above 40 degrees I move them back outside for a little fresh air. I'm really worried about the lemon.

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