Brown scales on Meyer lemon branches - Ask Extension
I have a 2 yr old potted Meyer Lemon tree that recently developed soft, brown, raised scales on some branches. The plant was brought indoors 4 months...
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Brown scales on Meyer lemon branches #783872
Asked March 12, 2022, 11:50 PM EST
I have a 2 yr old potted Meyer Lemon tree that recently developed soft, brown, raised scales on some branches. The plant was brought indoors 4 months ago for winter. It’s near a south facing window under a halogen lamp. Other than some leaf and bud drop, it seems healthy. No lemons yet. What is causing this problem and how should I treat it?
Thanks for your advice,
SUzanne AHn
Multnomah County Oregon
Expert Response
Hi Suzanne,
Your tree looks like it has scales, an insect that sucks the juices out of the tree and is covered with a hard or semi-hard scale. The easiest and safest way to get rid of these insects especially since your tree is small is to scrape them off with a metal nail file or an instrument similar to a nail file. This removes the scale and insect and does little damage to your tree.
These insects reproduce quickly and can move around. Remove the scale as soon as possible, bagging and putting the insects in the trash not outside in any compost.
Since you have not mentioned it and the tree is inside, I doubt you have ants, but the scale insect makes honeydew which the ants harvest and take back to their dens. If you decide to put it back outside and see ants on the tree, put a band of petroleum jelly around the base of the tree trunk. That will stop the ants from climbing the tree and harvesting the honeydew. Over time it will become cover with dust from winds, just re-apply the jelly.
Neem oil, an organic spray, works well but again the tree is inside so my first line of defense would be gently scrape them off. If you do decide to use Neem oil, buy the 100% pure, it is expensive but will last forever and does not have any 'inert' ingredients in it. Mix with water, follow directions on the bottle.
Here is a link with more information on scale insects on citrus trees: https://www.gardeningknowhow.com/edible/fruits/citrus/controlling-citrus-scale.htm
Your tree looks like it has scales, an insect that sucks the juices out of the tree and is covered with a hard or semi-hard scale. The easiest and safest way to get rid of these insects especially since your tree is small is to scrape them off with a metal nail file or an instrument similar to a nail file. This removes the scale and insect and does little damage to your tree.
These insects reproduce quickly and can move around. Remove the scale as soon as possible, bagging and putting the insects in the trash not outside in any compost.
Since you have not mentioned it and the tree is inside, I doubt you have ants, but the scale insect makes honeydew which the ants harvest and take back to their dens. If you decide to put it back outside and see ants on the tree, put a band of petroleum jelly around the base of the tree trunk. That will stop the ants from climbing the tree and harvesting the honeydew. Over time it will become cover with dust from winds, just re-apply the jelly.
Neem oil, an organic spray, works well but again the tree is inside so my first line of defense would be gently scrape them off. If you do decide to use Neem oil, buy the 100% pure, it is expensive but will last forever and does not have any 'inert' ingredients in it. Mix with water, follow directions on the bottle.
Here is a link with more information on scale insects on citrus trees: https://www.gardeningknowhow.com/edible/fruits/citrus/controlling-citrus-scale.htm
