Author Topic: Sweet Flag Infested with Scale (Read 2436 times)

Mikey · « **on:** February 18, 2007, 10:47:01 AM »

Here’s my problem. I have Sweet Flag growing in the rocks at water’s edge surrounding my pond. It has a nasty infestation of scale and I now notice that ants are apparently attracted to the scale as well. How do I get rid of the scale?

I use Ortho Volck Oil Spray for my citrus trees when they get scale but I have read the instructions and it warns that the oil is toxic to fish and as you see below the Sweet Flag overhangs the pond and its roots are actually in the pond. The scale can’t be hosed off with a strong stream of water. I could manually remove the scale by pinching the blades between my fingers and pulling on each one but that would take several hours because I have a lot of this plant along the edges of the pond…….

Any suggestions?

tranquility · « **Reply #1 on:** February 18, 2007, 11:30:10 AM »

I have never dealt with scale......hope someone has a solution for your problem....
Lawanna

Craig · « **Reply #2 on:** February 18, 2007, 12:35:44 PM »

Hi Mikey,

Acorus seems to be a favorite host for scale and scale can be a tough customer, especially if not caught early.

Normally I'd say to try an insecticidal soap, but that is more effective for new infestations. You might want to consider Orthene. It is both a contact and systemic insecticide and the only one I can think of that is not labeled as hazardous to aquatic life.

Here is part of one blurb on it: Not only is Orthene's toxicity to people and pets relatively low, it poses little hazard to birds, fish and wildlife when applied at labeled rates.

It is pretty much that or the mechanical removal you mentioned.

emm · « **Reply #3 on:** February 18, 2007, 01:28:05 PM »

Is it possible that the wasps and insects will remove it naturally? I have found that infested house plants will clean up nicely when placed outdoors for a few weeks. I have used Safer's Insecticidal Soap diluted with water and rubbing alcohol (rather than just water) to be effective on scale insects but again, I don't know what the effect will be on the pond inhabitants. If you do decide to use an insecticide you may be able to create a barrier between the plants and the pond with newspaper or plastic sheets. emm

Mikey · « **Reply #4 on:** February 18, 2007, 01:49:42 PM »

Thanks Craig and Emm. I'm not aware of a natural predator for scale although I'm sure there must be something out there that likes to munch on these pests. If I don't get any better recommendations I'll try using Orthene. I think I will lower the water level a few inches and I'll use a hand spray bottle with Orthene and also place a tarp or something beneath the leaves to catch most of the stuff that drips off.

tammie · « **Reply #5 on:** February 18, 2007, 02:13:37 PM »

You can use neem oil. Here's a link to the toxicity for fish
http://www.nysaes.cornell.edu/pp/resourceguide/mfs/08neem.php
Tammie

andrew davis · « **Reply #6 on:** February 18, 2007, 03:47:02 PM »

A question you might ask, is it really scale you are noticing. Acorus gramineus variegatus has very durable long lasting foliage which eventually will wither with one thing or another, with age.

Looking at the photo, I can't see much in the way of rampant disfiguring of the plant, just the usual fading of old foliage

AGV usually looks a bit blasted at the end of Winter, then neat new foliage comes gleaming through in Spring, are the new shoots affected... If they are not, it may be simpler to let the old foliage fade and wait for the new growth to replace it

With any chosen systemic fungicide or insecticide, it's quite feasible to target the plant only by applying the solution with a non dripping, sponge swab (wearing gloves) on a day of dry humidity, where the plant is more likely to absorb the solution and minimise any contamination to the surrounding area

Regards, andy
http://s93.photobucket.com/albums/l42/adavisus/

Craig · « **Reply #7 on:** February 18, 2007, 04:04:22 PM »

Hi Mikey,

The problem with Neem and the other oils ( soaps) from my experience is that they can't control a raging infection. Get the buggers in check and then they are fine for prophylactic treatments. So first the insecticidal guns may have to be brought out.

Orthene ( acephate) was first mentioned to me by a professional exterminator that specialized in pet stores as it was an insecticide safe enough to use there, it is biodegradable, so no concern about build up in soil or water....and I have no interest financial or personal in Valent ( the company that produces it<g>).

Mikey · « **Reply #8 on:** February 18, 2007, 08:11:54 PM »

Good suggestion relative to the sponge-bath idea Andrew. I hadn't considered that. I didn't take a close up photo of the foliage but trust me, it is crawling with scale. I saw it last year and did nothing and now I'm paying the price.....

I volunteered to participate in a Spring Garden Tour in May so now I'm paying the price for several years of neglect and procrastination.....

so now I'm going to have to get serious with these pests...

Craig · « **Reply #9 on:** February 19, 2007, 07:59:25 AM »

I hate to always seem to be argumentative, but the sponge bath thing is as a rule not practical on a scale larger than a few houseplants.

You need an even and thorough application to be effective and a sprayer is your best bet. With scale, the ones you are mostly after are the 'crawler stage' and they can be anywhere....even getting knocked off the plant during the bathing process only to return when the disturbance is over. Most stores sell a maybe 2 qt pump sprayer that works just dandy.

Another consideration especially for fungicides, but some insecticides as well, is that they are wettable powders and don't dissolve in water, so they need frequent agitation to stay in suspension. They also need to be applied at a given strength and rate....so with a dripping sponge it is going to be difficult to estimate what is the equivalent of say 1 pint/sq. ft for a given dilution. If you are off too much, you risk damaging the plants or building resisitance in the fungal target.

Anyway, just my thoughts on application methods. As to your specific problem, if you are not seeing a huge hatch of crawlers yet, a couple applications of Safer Soap or M-pede a week or so apart may well do the job fo you. Just be sure to use it before the sun is on the plants.

Sean · « **Reply #10 on:** February 19, 2007, 08:08:17 AM »

Hi Mike,

Wouldn't it just be easier to dig up the clumps, soak them away from the pond then plant back in place after the infestation has been eradicated? That is what I would do.

Cheers,
Sean

andrew davis · « **Reply #11 on:** February 19, 2007, 04:10:05 PM »

Ortho systemic insecticide with acephate as the active ingredient is readily available at the stores. Anybody keeping roses in good condition might be familiar with how effective systemic fungicides and insecticides can be.

Systemic materials don't have to be sprayed on, the plant absorbs the toxin, which the sap sucker extracts via the sap.

Pretty easy to stroke onto straight foliage like Acorus Gramineus variegatus accurately. A slab of polystyrene scrounged from the back of any furniture store would be effective to mask the work area from the water.

Sponge, cloth, kitchen roll could be tested to see which is easiest to apply a small quantity of solution accurately with minimal risk of error. I doubt it would take more than a dozen spoons of the mix to bump off the scale on the plants in the photo

Gently stroking the solution on to both sides of the leaves would be very easy on such straight regular leaf shapes

Regards, andy
http://www.members.aol.com/abdavisnc/swglist.html

Jerry · « **Reply #12 on:** February 19, 2007, 04:16:42 PM »

I was going to suggest what Sean said. They are in containers, so just take them out of the pond and treat them. if and when they recover put them back in the pond.
My Sweet Flag came from you. We can divide anytime you want. Thet seem to be doing very well.

Joyce · « **Reply #13 on:** February 19, 2007, 04:39:12 PM »

Yup, I'm with Sean and Jerry, it's that 'easy, safe, & efficient' method that works for me.

Craig · « **Reply #14 on:** February 19, 2007, 04:43:40 PM »

Lol....you apparently have more time than I. And Mike already suggested that wiping every leaf for scale would take hours.

Stroking risks dislodging the crawlers....as does moving the plants. So they( the crawlers) will still need to be dealt with in situ. Acephate is contact as well as systemic, so a spray is a more effective application ( and quicker) on the young'uns left behind. You see the adults, but it is the unnoticed little ones that are going to be waiting to re-infest you.

Not all pests are sapsuckers, systemics that are passed through the sap are ineffective against them, so you need a systemic that provides a translaminar flow. Anybody keeping plants in good condition is familiar with the selection and application of the proper systemic for effective results...and I have yet to read a label that lists an application rate of 'a dozen spoons or so' with no reference to dilution rate, spoon size or pot size/area to be treated.

But then chemical applications for pest control is not something that I approach with a cavalier attitude, so I read the labels and instructions thoroughly so as to never have to guess.

andrew davis · « **Reply #15 on:** February 19, 2007, 05:42:40 PM »

>> I have yet to read a label that lists an application rate of 'a dozen spoons or so' with no reference to dilution rate, spoon size or pot size/area to be treated.

It is fairly easy to calculate a measured custom quantity from the instructions on fda approved materials. Tablespoons per fuid oz are quite easy to measure and calculate. Fairly easy to take the equivalent of 12 spoons of the mix at a time, to the plant, and apply it. Why, you just spoon it out...

To apply a fluid to a fair proportion of the foliage surface is a very easy task. A lot easier than handpicking bugs individually, or risking sprays where the material is largely going to become airborne to miss the plant completely

Regards, andy
http://s93.photobucket.com/albums/l42/adavisus/

Mikey · « **Reply #16 on:** February 19, 2007, 06:47:24 PM »

Thanks for all the responses. The more information you provide gives me more tools to work with to get the job done. I appreciate the help.

Craig: I was at a nursery today and I forgot to write down the name "Orthene"

........ and the nurseryman couldn't think of a non-toxic to fish insecticide......so I'll have to return again tomorrow....with the name in hand....

Sean: The plants are not in pots. In the photo the rocks you see are resting on top of my liner in about 1/2 inch of water. What I did was to take bare root Sweet Flag and place it on top of the liner in between rocks. The roots actually attached themselves to the liner. They are not in soil and get all the nutrients directly from the water. And when I say attached I mean ATTACHED. I could pull them off and have done so in the past in order to share with others but it was very difficult. In addition, I would temporarily loose the very natural look that took several years to achieve and I have a garden tour coming through in early May..... The photo I took is of just a small section of Sweet Flag planted a few months ago and it was in the shade, making it suitable to photograph without a glare. On the other side of the pond, and in the sun, is a solid mass of Sweet Flag.

I'm assuming that any systemic action would occur from the roots absorbing the insecticide and passing it through the leaves. Is that correct? In my case there would be no systemic action since the roots are in water and of course I don't intend to pour systemic insecticide into the pond....

SheilaJ · « **Reply #17 on:** February 19, 2007, 07:15:51 PM »

I was also going to suggest a systemic applied to the soil, but since there is no soil, that's obviously not an option.

How about this - after your garden tour, can you whack back all the foliage to stumps? I've not grown sweet flag so I don't know if it would grow back in well or not. But we have liriope in containers that gets scale and a serious haircut gets rid of most of it. Especially if the scale is concentrated near the tips of the leaves.

Another option, especially after you do the haircut approach, is repeated spraying with horticultural oil, assuming there is one that is safe for fish and won't gunk up your pond (you'll have to read the labels for that, of course, I'm merely speculating here). I have been able to keep scale reasonably in check on most houseplants by weekly heavy spraying with a hort oil. Of course you can't spray when the sun shines or you'll fry your foliage.

Sounds like the Orthene is going to be your best bet, though.

Sean · « **Reply #18 on:** February 19, 2007, 07:52:13 PM »

I have made my own insecticidal soap before with just a combination of "Phosphate free" liquid soap, Hydrogen Peroxide and Rubbing Alcohol mixed together, slightly diluted with water and sprayed. I use it on aphids and have also used it with terrestrial plants for scale. It is safe for fish as proven from a few years using it to control aphids on my tropical waterlilies with no adverse affects to the fish.

Cheers,
Sean

andrew davis · « **Reply #19 on:** February 19, 2007, 07:59:21 PM »

>>I'm assuming that any systemic action would occur from the roots absorbing the insecticide and passing it through the leaves. Is that correct? In my case there would be no systemic action since the roots are in water and of course I don't intend to pour systemic insecticide into the pond

No, you don't want any insecticide to go into the pond water. You might look up 'acephate toxicity' in google and look up research data where folk have tested the impact of its affect.

Quite often there is precise data at which a material has been measured to be benign or toxic, which helps make taking a calculated risk

Acorus Gramineus Var. tends to make tough roots a foot or two long, they would have a tenacious grip among the liner and the rocks. How easy is it to dismantle the rocks, and put them back vaguely intact to re establish... no chance.

Systemics work by being absorbed by the foliage. Spraying, painting, stroking it on works fine, though wiping the foliage is probably the most efficient, accurate application, two non dripping swabs could stroke twenty, thirty stems at a go.

Occasionally I see aphids taking off in indoors positions on tropical waterlilies and stems. No way do I want to spray insecticide indoors, nor is it practical to move large heavy tubs that may split. Swabbing the leaves usually clears the plant up in less than a week, with no impact upon the aquatic worms in the lilypot.

With the plant being in a difficult pondside position, the choice of ripping it out, or applying insecticides, or leaving the infestation to do its worst and become a source for further trouble is not a pleasant choice.

A slab of polystyrene to mask the area and accurate swabs of Ortho Acephate may turn out to be a fairly easy option compared to ripping the position apart and applying insecticide on them elsewheres, to put the plants back where the pesky hordes of scale continues to lurk...

Regards, andy
http://community.webshots.com/user/adavisus

Craig · « **Reply #20 on:** February 20, 2007, 10:19:31 AM »

Hi Mikey,

Sounds like more than a 'twelve spoon 'job to me, but again, I am religious about following the label instructions to a tee as they have been approved by the EPA and they specify to spray the target plants for full coverage. And repeat at about 2 week intervals. I am using a 97% acephate formulation, so your label instruction may vary with the strength...but I'll bet they still advise you to spray and wear a long sleeve shirt and pants in addition to just gloves.

While it is not accurate that all systemic pesticides are effectively absorbed through the foliage, as luck would have it...Orthene is. The added bonus is that it is also kills on contact, so the crawlers can be dealt with before they set up to start sucking. If you have any foliar feed around you might want to mix the Orthene in a half strength fertilizer solution. There is evidence that nitrogen containing fertilizers enhance the absorbtion.

If I have one concern, you mentioned that you noticed the sweetflag was "crawling' with scale, which I take it you mean figuratively. But if you actually noticed creatures crawling, it could be mites and the Orthene is useless. I suspect you are hip to the difference in the two pests, but still thought it was worth mentioning.