If you don't mind using some heavier artillery, a systemic with imidacloprid as the active ingredient will help a lot. But a heavy scale infestation is hard to control and sometimes it is the smartest thing to rid yourself of those plants and start over. IMO, that is not a "quitter" attitude but a realistic one.......scale are one of the hardest insect pest to successfully control, indoors or out. And also one of the most damaging.

I’m so sorry Sammers! If I lived near you, I’d come by and help you remove nasty critters and wipe leaves. I spent many nights this winter wiping down each individual leaf with alcohol, while a movie played in the background. I’ve had a constant low level bug attack and I’m grateful it’s never gotten out of control, but did kill my 2 baby Meyer Lemons.

I’m sure you’re devastated right now, but don’t give up hope. Yours trees with severe dieback might still come back and you might have to sacrifice the worst of the victims, but you can probably save most of them. Nearly every week, I spray with the hose, then wiped with alcohol and finished with HO. Sadly, I picked two scale bugs off a tree this week, so there must be more...

I’m a pretty natural/Organic believer and some people think I take it too far, but if it means throwing your trees out or using some severe chemical insecticide, I’d choose the insectide...or at least give it a try. It breaks my heart of see my trees suffer.

I wish I had better advice, but I’m no where near as knowledgeable as the rest of these guys. Good luck and keep us posted.

So sorry, Sammers! I’m with Alanna - I would help you as well. Sending good thoughts your way.

I agree with Alanna

Sammers, I hear you, my rescued lemon tree had bad scale infestation, after so many treatments with horticultural oil since December I found scale on the leaves again :( it is difficult to get rid of them.

Don't throw away any trees until they are dead.

Steve

Sammers - we are all with you. *hugs* In response to this - "only really went in to water and check on the lights the last 2 months. And now I am paying for it" - don't feel bad because there are some of us (me included) who were carefully checking each day and trying to correct issues, and are still "paying for it" for some of our trees.

I am thinking that there will always be a huge adjustment that these trees need to go through after leaving the care of a nursery, and then suddenly plopped, in some cases, into a totally different environment. And that adjustment period will probably take time. If the trees survive that, then the hope is that the old adage will apply - "What doesn't kill it makes it stronger" (or at least "better adapted" to its new environment).

As a sidenote, I have a tropical hibiscus ("Snow Queen", which has variegated leaves and produces deep red flowers with huge stigmas and styles that extend far beyond the petals) and it is an evergreen, like the citrus. Yet I know when I bring it in to overwinter (with some light and just water), it will inevitably drop leaves in piles, but it always grows back so lush that I have to cut it back. I don't even think about it and just try to make sure that it gets fed and watered and given sun once back outside. I need to mentally start thinking that way for the citrus as well.

Thank you all for your kind words and encouragement, its just what I needed. I have separated the plants that I know have scale into a different room and will be pulling them all outside tomorrow for a good shower, some spraying and more squishing. I know they will only be inside for another few weeks so that helps me de-stress a bit as my plants almost always do better outside. I just have to get back into the citrus rhythm as I have been so distracted by planning and remodeling (and seed starting) my back yard with raised beds for veggies, and various trellis for beans, peas, tomatoes and peppers that I barely had time to think about potting up the dozen figs I have this weekend between gardening classes and volunteering let alone dealing with a major scale infestation. I thought I had some more time before the high maintenance citrus came back into play but as with most high maintenance things they don't let you not deal with them for long.

Gardengal, if I did want to use something more serious to treat would any of these work?

Bayer Advanced

Compare-N-Save

Bonide Insect Control

If not do you have a particular product your recommend? I also assume I wouldn't be able to eat and fruit off these trees this season if I go this route since none of these products seem to be recommended for edible plants?

I like the Bayer product (not familiar with the second and acephate is a scary pesticide I would prefer not to use). And you can eat fruits from plants treated with imidacloprid - it is not present in heavy enough concentrations to present any sort of toxicological concern. There is also a Bayer product formulated specifically for edibles: Bayer Fruit, Citrus and Vegetable Insect Control.

Thank you so much, I will order the Bayer fruit, citrus and veggie control today. While I prefer to keep my gardening organic I am not above doing what I need to the save the trees or make it easier on them (and me). My supermarket fruit and veggies likely have something similar or worse used on them so whats one or two more in the long run.

Imidacloprid is quite ineffective against scale when used on citrus as a systemic. You're better off combining a horticultural oil with a pyrethrin (and if you need to make it stronger, you can find a product with a synthetic adjuvant).

It is just as effective on citrus as it is on any other type of plant affected by scale. It is just not very effective against armored scale. But then, most scale issues with citrus tend to be focused on soft bodied scale.

Gardengal, it is not very effective against scale. It will not eradicate them. I can link to several scientific papers and articles saying as much.... Here are some:

Role of imidacloprid in integrated pest management of California citrus.

CROP PROFILE CITRUS IN CALIFORNIA

International Conference on Integrated Control in Citrus Fruit Crops

EFFICACY OF SYSTEMIC INSECTICIDES AGAINST THE CITRUS MEALYBUG, PLANOCOCCUS CITRI, AND PESTICIDE MIXTURES AGAINST THE WESTERN FLOWER THRIPS, FRANKLINIELLA OCCIDENTALIS, IN PROTECTED ENVIRONMENTS

Scale will climb the branches to expand the used space. Being a sad man with scales, I have removed heavily infested leaves and painted all the branches, from roots to the tip of my little tree, with acrylic paint. I'm sure scale will not appreciate the taste, dryness and thickness of acrylic paint....

Did you dilute the paint,eSilviu?

I can really relate to the frustration. My last aquisition was a clearance score, and I knew it looked rough, but hoped for the best. Not only does it have nutrient deficiencies, I just found scale on it last month. I checked it right after buying, but forgot how really inconspicuous scale can be. This stuff is transparent and very thin. No mistaking sticky leaves, tho. And since I don't have enough space to properly quarantine, good chance it has spread. Ugh.

Have you used surfactant with your HO? I think mine has it included, but silica mentioned adding it, so I may try that. I think I read that it is critical to spray at crawler stage, but I don't know the different stages.

Thank you Tom, I just have to keep holding out hope that it will all work out! I can't wait for the warm weather to get to me.

Oh I am so sorry to hear all this Sammers! I wish I could help. I have to second Tom and say that horticultural oil works wonders. It wont completely eradicate but it will reduce the numbers and let the trees recover. Let me know how the heavy pesticides work out. I might need to use them one day!

Amanda, Its great to see you on again. How is your garden doing? I hope your trees are doing well.

I have stated with the HO and will see how it goes, now I know not to stop treating so soon once I think they are gone.

My citrus trees are good! My calamondin is pumping out fruit haha. My gold nugget has 4 (just found the fourth this morning!) nice sized fruits on it and I keep removing the little fruitlets that form. I don’t want to stress it while it’s inside. My two baby mandarins are doing great and one is sporting it’s first fruitlet. I need to pull it off but it’s so cute hahaa. Everything outside is starting wake up and this weekend I am planning on prepping all the soil if it’s not too cold. Nursing school is a handful and I want to pull my hair out haha. I hope you can cure your trees. I know the heart ache all too well.

Sammers I too am very sorry!! But not all hope is lost! Is it too early to leave them outside now Sammers?

When I was once in the dark about getting rid of scale, I am talking a HUGE mass of them all over my Ponderosa Lemon and Olive Tree, I used what Tom suggested and what Gardengal suggested all at once..Let me tell you when I say I got completely rid of them in just a month spraying once a week. I brought mine outside and spray and watered them in. I have never seen them since. Try both!

When you get them outside, spray every tree down with the 'All Seasons Dormant oil and then water them all in with the Bayer. That did the trick for mine for sure!

I never threw a tree away to pest, because for every pest there is a simple solution if given the right advice and using the right products..

https://www.ebay.com/itm/1-BONIDE-32-OZ-RTU-HOSE-END-ALL-SEASONS-SPRAY-HORTICULTURAL-DORMANT-OIL-213/172149772721?epid=1000020153&hash=item2814ed11b1:g:osMAAOSwI3RW-VqX

I just read something that said it’s essential when using pesticides that require water, to ensure that water is slightly acidic for the pesticide to work properly. I spent hours reading about citrus today, so I can’t remember where I saw it.

Thanks Mike, that gives me hope! I am dragging them all out tomorrow and hoping I won't need to pull them pack in. I'll go ahead and start treating with both and hope it does the trick!

Sammers, how are your trees doing? Were you able to get the upper hand on the pests?

Neonicotinoids like imidacloprid are not effective against significant scale infestations. If you are inclined to apply pesticide chemicals, Movento (spirotetramat) for hard scale and pyriproxyfen (eg. Admiral) for soft scales are comparatively 'mild' and selective insecticides which act long term but should be timed correctly. Otherwise you will have to use some organophosphate. Horticultural summer oils are a good solution if applied consistently.

Sammers, how goes the battle? Are you able to still leave them outside?

Next summer, although some think it a waste of time and a 'snake oil' remedy, invest in the F.E called 'Neptune's Harvest', it's a cold pressed fish emulsion that carry natural oils and feeds your trees at the same time. It will help prevent bringing sucking pests from ever taking a hold, at least this is what happens in my case now. Spray the leaves down all summer long at least twice a month and every week in September before bringing them inside.

Mike