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andrew_scott77

Any tips on removing scale from citrus trees?

Andrew Scott
13 years ago

First I want to start off by apolgizing for not asking for everyone's help with my original thread. I know there are quite a few people here that have experience with bug infestations on there citrus trees.

I want to give everyone a quick background of my situation.

I first found some large scale on my Oro Blanco grapefruit tree. I hand picked them off and then checked each and every tree and then sprayed with FE. I am just kickin myself in the butt for not doing this before I brought them in, it was my intention to do this but time got the best of me. I then re checked my trees and found more scale. It had spread to my other Oro tree which like the other is just flushing with new growth and flower buds, and also to my mango tree.

I mixed up a strong spray of rubbing alcohol and water. I doused every plant in that room to try to rid them. Thursday was when I sprayed with the rubbing alcohol solution. This morning, I found scale on a couple leaves that were on one branch of my keylime tree. This tree is pretty large and it was not easy to wash and rub each and every leaf along with each branch. The worst tree of them all is the Gardenia tree. It is just so thick and lush I am really worried about trying to keep it pest free. I considered moving it to the basement for 2 days just so I could keep spraying and checking it to make sure that there are no bugs and then return it back to my grow room. I have not found any on it but trying to find it on an almost 5.5 ft tree and almost3.5ft wide tree is really hard.

I have heard of systemics that can be used to kill bugs on trees. My tangerine was treated with a systemic back in September and i think this is why there are no bugs on it. My question is will it hurt myself or others who eat the fruit after being treated with a systemic?

Also, I would like to know how long I should keep up on the spraying after I don't find the scale anymore. I was thinking if I don't see any scale for maybe 4 or 5 days, than maybe I could spray another couple times to make sure there are no eggs, and hopefully get rid of them once and for all.

Any suggestions or opinions on this would be greatly appreciated!

Andrew

Comments (41)

  • thisisme
    13 years ago

    Yea dormant oil or neem oil will do the trick. Neem oil is also a mild systemic that should not hurt the fruit or anyone who eats it.

    The EPA (US Environmental Protection Agency) says neem is Generally Recognized As Safe (GRAS) for use in food products. They even exempted their typical requirement for maximum pesticide residues on agricultural products.

    If there are no restrictions regarding maximum allowable residues for farmers, then you also don't have to worry about residues from your neem spray in your vegetable garden. Yes, neem spray is safe. A heck of a lot safer than all the other sprays you ingest with conventionally grown produce!

  • cath41
    13 years ago

    Andrew,
    I have successfully used straight rubbing alcohol applied with a toothbrush to get rid of scale. The toothbrush gets the adults off of the leaves and stems and the alcohol kills them and removes the goo they create. We should all probably check the citrus occasionally for scale. I swear it comes out of thin air. The ancients used to believe insects generated spontaneously from mud and I am beginning to believe them. LOL. But you should check the scale's life cycle to have a better idea of when they are likely to reappear. I think that they are less susceptible at certain stages such as the egg stage and so the scale in the egg stage will continue to hatch for awhile.

    Also, beneficial nematodes have given my citrus extended protection of maybe a year and have the side benefit of eliminating fruit flies. I must admit that although i know this I am behind on applications. Hope that this helps.

    Cath

  • cath41
    13 years ago

    Andrew,

    I have successfully used straight rubbing alcohol applied with a toothbrush to get rid of scale. The toothbrush gets the adults off of the leaves and stems and the alcohol kills them and removes the goo they create. We should all probably check the citrus occasionally for scale. I swear it comes out of thin air. The ancients used to believe insects generated spontaneously from mud and I am beginning to believe them. LOL. But you should check the scale's life cycle to have a better idea of when they are likely to reappear. I think that they are less susceptible to treatment at certain stages such as the egg stage and so the scale in the egg stage will continue to hatch for awhile. I vaguely remember 3 days but I'll bet it is somewhat temperature dependent and you should check this for accuracy.

    Also, beneficial nematodes have given my citrus extended protection of maybe a year and have the side benefit of eliminating fruit flies. I must admit that although I know this, I am behind on applications. Hope that this helps.

    Cath

  • meyermike_1micha
    13 years ago

    Andrew..This is what I would do..

    I would trim the larger trees back and I don't care what time of the year it is..Citrus trees are resilient to pruning even now..This is exactly what I did one year to mine..Then I would spray entire tree with a good horticultural oil..

    Many who have so many trees that do not eat the fruit, if it were scale or mealy would treat with systemic..IT WORKS..But the key is to treat when trees are actively drinking.

    You have to have a good eye to hit every bug with so many trees..

    Andrew, that is why I was stressing so much to use FE all summer..It does the job and every year so far faithfully doing this every week has made my plants pest free..Next year I will have to push you hard..:-)

    Take care my friend..

    Mike

  • Andrew Scott
    Original Author
    13 years ago

    HI Cath,
    I like this toothbrush idea with the straight rubbing alcohol. Thanks for the tip.

    Mike,
    Believe me or not, I swear to god, I have NEVER had this problem. EVER!! I believed you on the FE but I just procrastinated until it was too late. Most of my trees are still small except the gardenia tree and my keylime. I am seeing fewer and fewer and they are really small right now. I am not seeing the big honkin adults that I had when I first found them. I really do not have the want to spray again today but I am. Instead of using a dilution of the Rubbing alcohol, I am going to go at it with 100% rubbing alcohol, then put them under the shower to rinse. At the rate I am seeing them now, I really don't think it will be too much longer before there gone. I may just by the systemic for the fruit trees that I know are not going to fruit for another year(not my citrus).

    Thanks evrybody for your help. I will keep you all posted!
    Andrew

  • rhizo_1 (North AL) zone 7
    13 years ago

    The rubbing alcohol will continue to be effective as long as it is wet. Rinsing it off doesn't make any sense, unless you think that you will be protecting the foliage from harm. Many people spray full strength rubbing alcohol on their plants with no harm. After all, we use it on our own bodies, right?

    I wish you'd post an image of these insects so that they could be properly identified. Knowing the type of scale can be important in choosing the best control measures. There are about 1000 different species in North America. For example, some types of scale are not readily controlled by oil applications. And others may not be hindered by the alcohol treatments. Some lay their eggs underneath their protective scale covers, while other carry egg sacs around with them. So, let's see a picture.

    If you are going to use a systemic (not something that I would recommend), be absolutely certain that your product is clearly labeled for INDOOR use. You don't want to be subjected to volatile fumes for weeks on end.

  • Andrew Scott
    Original Author
    13 years ago

    Hi Rhizo,
    According to the Four Winds citrus site, it is Cottony cuahion scale. They have a slide show of diffrent bugs that can harm your trees. I went there on a whim just to look around but came across this slide show and was able to positively I.D. it.
    I will see if I can get the link but I will say that the alcohol did help a lot. I always thought the 100% alcohol would injur the leaves so thanks for clearing that up. I did find one of these ugly critters on my plumeria a few days ago but I think I really got the most of them. Now, it is maintenance. This year as been the worst for me in the bug infestation department. I have probobly quadrupled my all around collection of tropicals and having them be in a nice warm room with the 600 watt HPS light just makes them want to "party on my plants" even more!
    Enjoy your Thanksgiving Rhizo and thanks for responding to my post. I should have opned this up to you from the very first post. I know you know your stuff! I apoloigize. I don't know what I was thinking!!
    Andrew

  • rhizo_1 (North AL) zone 7
    13 years ago

    I thought it might be (the dreaded) cottony cushion scale, Andrew, though I think of that species as being more common in warmer climates. Be sure to focus your eyes on finding the scale MINUS the egg sac, too.

    Cottony cushion is one of the species that can be nicely controlled with the alcohol application. Use a little plant mister to get the stuff in all the nooks and crannies where the tiny crawlers are. Those egg sacs contain several hundred eggs! Once they hatch, it's like a wave of tiny crawly babies scattering to all parts of the plant. Alcohol can really do a number on them while still young.

    About rubbing alcohol and plants: think before spraying. If the foliage is very soft and tender or fuzzy, don't use it or do a leaf test first. Avoid tender flower petals. I've used it for many years on a vast number of plants for the control of spider mites, mealybugs, some scale species, aphids, and thrips. I always use a sprayer and usually mix it with water, but not always, at the rate of one part alcohol to three parts water. As with any plant product, don't apply it in the hot blazing sun or when the plant is wilted.

    Our friend Mike directed me to this post, as I don't over here as much as I should! Don't hesitate to email me directly, if you think I can be of any help.

    Here is a link that might be useful: {{gwi:641725}}

  • call_me_wizfire
    13 years ago

    ouch, rhizo, are those your scale? im glad i dont have any

  • meyermike_1micha
    13 years ago

    Digusting Rhizzo!lol

    Anyone who let's their plants get that infested shouldn't be growing them at all, especially in-door ones..Yikes.

    Mike:-))))

  • rhizo_1 (North AL) zone 7
    13 years ago

    wizfire!! They aren't MY scale! Good grief, no way.

  • call_me_wizfire
    13 years ago

    sorry, lol, and good

  • subyz
    12 years ago

    This is too funny! Your posts are almost exactly ONE YEAR ago! It's also Saturday but only the 12th (2011). I hope you are still here! I just found scale on the Persian Lime and Meyer's Improved lemon I brought in last week. I have had the trees for a couple of years. Neither produced any fruit this year, but they did last winter. My lemon has bouts of very yellow leaves and curling. I treated it for mites even though I never found any. Safe soap spray of some sort. Now I read on some websites that oil (neem , although my horticultural oil just says 'Petroleum oil' but lists citrus as OK.) and others say rubbing alcohol. I even saw 'Simple Green' Anyone know what I ought to do for these neglected sickos?

  • subyz
    12 years ago

    Photos (such as they are): http://www.flickr.com/photos/28105946@N06/sets/72157627988822

    Here is a link that might be useful: Flickr 'Sick Plants'

  • susan2010
    12 years ago

    Okay, I must have slept through this discussion, and I apologize. But is FE fish emulsion, or something else? If so, how is it used to prevent pests? How does it work? I Googled (and I'm a pretty good Googler), and I did not find anything beyond using it for fertilizer. I've learned not to assume I understand everything written by the pros here, so I thought I'd ask for clarification. Thanks!

  • rhizo_1 (North AL) zone 7
    12 years ago

    susan, FE is fish emulsion. Some people have found it to be somewhat effective in controlling the same list of plant pests often targeted with horticultural oils. Those pests would be spider mites, mealybugs, scale insects, and similar. The reason for the success is the oil (fish oil) in the product. However, it is a very stinky method of control and I think that most people would be better served by using one of the many horticultural oils readily available. Neem oil is a plant based product with very good insecticidal and fungicidal properties and a good choice for a wide variety of problems.

    sub, I suggest that you be careful about applying a large combination of products. In your case, with so many problems, I'd recommend that you find some Neem oil. Not only does it have the physical affects of a horticultural oil, but it also acts as an anti-feedant. All those notches appear weevil-caused but could be a number of things. The neem can prevent that kind of feeding.

    As far as the yellowing goes, I suggest that you consider the kind of potting medium, your fertilizer program, and other factors.

  • susan2010
    12 years ago

    Thanks! FE is way too stinky for indoor use, but now that I know it has some effect, I may give my citrus a spritz when I feed my tomato plants in the summer.

  • loccorock
    9 years ago

    98% rubing alcohol killed my potted 3yo lemon tree. I washed it with a toothbrush in order to remove heavy infestation of the gray scale bug. Tree wilted in a week.

  • Leslie
    9 years ago

    Hi All! I really need some help! I have a 8 yr old lemon tree that my daughter started from seed. It is now about 8 ft tall in the pot on my screened in patio. It is flowering for the first time, and now is getting infested with mealy bugs! Do you think that it would be safe to spray while it is in bud and flower? The tree is too tall for me to use alcohol. I live in the Tampa Bay,Fla.

  • myermike_1micha
    9 years ago
    Any mix with an oil base in it will destroy the fower buds when they are mature, ready to open and flowers.....If you plan on using an oil base, I would rinse the buds and flowers off with a very warm soapy water a half hour later or so..
    I think there are safe pesticides you can use that have no oils, like Safers Soap or others that can spare your buds and flowers, but can't think of it at the moment...
    I would call your closest Nursery and ask them if they have a safe spray you can put on the end of your hose..They have many
  • kflann042
    8 years ago

    Hello anyone, needing some help with my 3yo lemon tree. I thought it was dead but it has come back and is now 3ft tall. However, I just discovered it is covered in scale insects, quite badly I'm afraid to admit. I cut off the branches that were too covered to save & scraped off the trunk what I could however, I'm noticing on a lot of the leaves they have some eggs or females still on them. Any good idea how to get these off & gone? I noticed a trend of either rubbing alcohol or neem oil?? Which one is best to use? The tree just produced some fruit this year (1st time), so I'm not interested in eating it, but I just don't want to kill it. Please help!!

  • myermike_1micha
    8 years ago

    Then you you don't plan on eating the fruit, use a good systemic...Many here use them even on their orchards...Rubbing alcohol and neem will never rid them completely unless you are constantly treating and it can take quite some time.

  • kflann042
    8 years ago

    Thank you, Mike. Any good recommendations for a systemic then? I've never used one before.

  • tim45z10
    8 years ago

    I used Bayer systemic for the first time this year.

    the pic of the cushiony cotton scale also has some kind of mite on it too.

    for pests start with a soap spray then move to Spinosad, which does not work on cotton scale,

    then the oil.

    then systemic if necessary.

    my citrus gets scale, x2, white flies, leaf miners

    tired of my trees getting sucked dry and looking ugly.

    pic of an orange and a tangerine


  • dimitrig
    8 years ago

    Not on citrus, but on my gardenias. I used Volck Oil with good success.

  • myermike_1micha
    8 years ago
    last modified: 8 years ago

    Tim, GOOD WORK!

    What pain that bugs like our trees...Where did these pests come from originally and for what purpose? lool

    I have to give it to ya..That is a lot of tree to work with and it's a wonder you hit every bug..I thought dealing with small potted trees was hard enough..You made me feel better about mine)

    Your trees are beautiful

  • janecat2
    7 years ago

    Can anyone help? 3 weeks ago I found scale on my 3 ft tall dwarf citrus tree and I cleaned the entire tree and in every crevice with a toothbrush and a mixture of 1 part rubbing alcohol and 1 part water. Let it sit for a few hours then doused with neem oil. I lost maybe 2 or 3 leaves in the vigorous cleaning process. Within 3-4 days i could see the scale returning on the leaves but not the steams and I picked them off with a cotton swab.


    Now 2 weeks later my plant has lost about half of its leaves and the the scale is back on the stems and leaves. I gently rubbed the plant down again with rubbing alcohol and lost more leaves. I had a wonderful bushy tree before this and now I have a naked (dying??) tree.


    What should I do? It's currently an indoor plant but the weather in NY is more stable now so I was thinking of putting the pot outside but I worry about bad winds and too much heat/sun on a vulnerable plant.


  • v_margarita9379
    7 years ago
    last modified: 7 years ago

    Scale problem as well we just bought a house and we have 4 trees in the backyard 1 lemon 2 nectarine 1 peach all which are dying I've been trying to revive them but no clue about trees it's a learning process just literally got inside from spaying all my ants down with dawn and found this feed on scale so so glad I did I can't believe this was started 10 years ago I need help with these poor trees don't want to get rid of them but might have no choice considering their health thanks

  • johnmerr
    7 years ago
    last modified: 7 years ago

    If you have, or can find even a small colony/nest of Brachonid wasps, they do a very good job of keeping that scale under control. They charge you nothing; and they never ever sting you.

  • Cathy Head
    7 years ago

    I have Plum and Citrus outside. I noticed the scale was really bad on my plum trees this year. My mom told me that the old timers would hang a bar of octagon soap in the tops of the trees, and when it rained it would drench them...lol...I'm going to try!!!

  • Vladimir (Zone 5b Massachusetts)
    7 years ago

    Don't waste your time with octagon soap old wive's tail. Spray with neem oil.

  • myermike_1micha
    7 years ago

    Horticultural Oils work wonders!! You could use 'All Seasons' and that would do the job....They have 'nose end spray' ones that make it very easy to treat trees all at once..

  • User
    7 years ago

    I just so happened to have spent time today ridding a Glens Mango of a heavy scale infestation.

    First I removed as many as I could with slightly soapy water and paper towels, then I will hose it down, then some insecticidal soap. Tomorrow, it goes outside and the sun and rain will work miracles!

  • emmett518
    7 years ago

    I spray with insecticidal soap, and two weeks later, Neem oil. I alternate every two weeks. So far, I've not eradicated it, but it's under control. Both of these are cheap, non-toxic, and easy to apply. I feel much better about spraying this stuff around, instead of more neurotoxic alternatives.

  • pjsodaro
    5 years ago


    Hello everyone. My dwarf Meyer in a large terracotta pot has/had a severe infestation of scale I caught later in the game rather than earlier. I thoroughly cleaned off the scale by hand and a toothbrush. The branches appear alive but ALL of the leaves appear withered and dried. I fear it went on too long unnoticed. I watered with a liquid fertilizer to encourage new growth. Should I remove all of the dead leaves? Would this encourage new leaves? I did not use a soapy solution nor did I use neem oil. It's been roughly one week. I do not see a reinfestation.


    I hope I didn't lose the tree and it can recover. Any and all suggestions would be appreciated. Thank you.

  • Vladimir (Zone 5b Massachusetts)
    5 years ago

    Looks like it needs water. Is the soil dry?

  • emmett518
    5 years ago

    One of my lemons almost lost all of the leaves, but it came back. Don't give up hope. That plant does look like it needs water.


  • Brian Warford
    2 years ago

    Will repotting my lemon tree help to get rid of the scale?

  • Silica
    2 years ago

    Repotting will have nothing to do with rid your tree of scale. A horticulture oil, neem or soapy water spray will kill them rather quickly.

  • Meyermike(Zone 6a Ma.)
    2 years ago

    NO it will not. Horticultural spray will and you have to be consistent about it. Some even use systemic..