Phosphorus mobility is a 1, it moves down very slow if it's dense clay on top, thus Mary Magdalene at 1/2 size (tiny bloom) doesn't get any benefits from Coop-Poop NPK 2-4-3.

Above is Pat Austin on Oct 7, blooms don't get deeper orange with horse manure, thanks to thick clay & red-lava on top, which blocks the trace-elements of horse manure.

Nutrients deficiencies that show at the top & affect blooming of plants: calcium, iron, zinc, and copper move down very slowly, thus loamy topping like compost is best, or putting that INSIDE the planting hole, such as mixing gypsum/lime or compost in the planting hole. These are best as SLOW-RELEASED.

Nutrients deficiencies that manifest at the bottom of plants: nitrogen (10 mobility), potassium (3 mobility), magnesium can be easily supplied on top. Except for phosphorus, which is VERY SLOW to move down. Research showed that it takes phosphorus 1 year to move down a few inches in clay soil.

Before I winterize my roses, I'll do late-fall fertilization after killing frost with coop-poop NPK 2-4-3, before adding soil and alfalfa hay on top .. that's for branching & more blooms and larger blooms in spring.

Aileen (totoro): 1 cup is OK if there's tons of rain, but if there's no rain & hot summer, 1/2 cup is best. Two cups is way too much, chicken manure has at least 10% salt, I burnt my roses before with 1 cup chicken manure in hot June.

Sulfate of potash/gypsum provides acid (sulfur) to turn the switch on for roots to secrete acid for blooming. But chicken manure NPK 2-4-3 is needed at the same time for branching and larger blooms.

David Austin's rose food has NPK 9.5 - 7.5 -10. At 1 cup of chicken manure, the ratio is doubled from 2-4-3 to 4-8-6, which will surpass David Austin's ratio if sulfate of potash/gypsum is also used to induce blooming.

Higher nitrogen uptake is achieved by raising the pH to neutral/alkaline (more nitrogen, potassium, calcium at pH 7 to 8). Also air is composed of 78% nitrogen and 21% oxygen, thus making soil loamy is enough to promote growth. Also calcium boosts uptake of nitrogen, Coop-Poop has 8% calcium to maximize nitrogen absorption.

Below shows the explosion of leaves & branching by 1/2 cup of Coop-Poop NPK 2-4-3, thanks to 8% calcium which boost nitrogen-uptake, that was applied mid-Sept, and below pics. are taken on Oct 7, which is 3 weeks of growth from Coop-poop.

First pic. below is Dee-lish (bought mid-May) with Coop-Poop, pic. taken Oct 7:

Second pic. below is 2nd Dee-lish bought end of June with 1/2 cup Coop-Poop:

I use 4 part chicken manure (way before blooming), 2 part gypsum or lime (end of bloom), and 1 part sulfate of potash (to induce bloom), that translate to 1 cup chicken manure, 1/2 cup gypsum or lime, and 1/8 cup sulfate of potash for a large rose bush.

Hydrated lime is quick lime mixed with water, it's the same nasty lime added to tap-water to deodorize. Quick lime is made by heating lime at extremely high temp at 825 C. or 1,517 F. It's an unstable chemical which binds with other nutrients, making them unavailable.

Have you ever noticed that watering with tap water makes roses pale, plus less blooms? The unstable hydrated lime binds with phosphorus and potassium into solids, plus zap out trace elements like zinc and iron.

Hydrated lime in tap water is what makes "concrete" out of clay. Wikipedia wrote: "Quicklime and hydrated lime can considerably increase the load carrying capacity of clay-containing soils. They do this by reacting with finely divided silica and alumina to produce calcium silicates and aluminates, which possess cementing properties.[8]

Here's the link to "oyster shell" lime on Amazon, 6 lb. for $11. It has trace elements, which are NOT in slow-released Espoma Garden Lime (dolomitic lime) sold at Walmart for $10.

https://www.amazon.com/Down-Earth-6-Pound-Oyster-Shell/dp/B001B2W8BA/ref=sr_1_1?ie=UTF8&qid=1475938618&sr=8-1&keywords=oyster+shell+lime

When the leaves are dark-green but dull, it means too much acid is produced, and it's time for pH over 9 lime (calcium is best in tiny doses).

See below upper dark-green leaves on Pat Austin, due to acid-phosphatase by roots to form blooms. This is when shell lime should be applied to neutralize the acid. Lime should be applied NEAR END OF BLOOMING, rather than before blooming:

Compare to below Pat's healthy-pale color, slightly alkaline with very thick and glossy leaves. Raising the pH with shell lime in horse manure helped leaves to be larger & glossier & thicker.

It's easier to observe the leaves, rather rush out and dump lime right before a rain. Sometimes rain come unexpectedly, so I would rather plan ahead with slow-released organics.

I don't give Crown Princess Magareta alkaline stuff, since new leaves are pale (see pic. below). But I notice Pat's leaves are getting too dark-green, same with Prairie Harvest, so both get horse manure (pH over 8).

Crown Princess Magareta has excellent branching, so it really doesn't need high-phosphorus Coop-Poop NPK 2-4-3. It's the one-cane wonder Veteran Honor in a pot, that should had gotten chicken manure for phosphorus to branch.

When roses are slow in growth, calcium is lacking. Marie Pavie was cute & compact until I gave it Azomite (instant calcium) one summer, and the bush exploded. Same with Crown Princess Magareta with gypsum, or Munstead Wood throwing a 3 feet octopus cane with gypsum.

How do one know to give gypsum (acidic), or lime (alkaline) for fast growth? Munstead Wood always has pale leaves, so it's hard to tell.

In extreme acidity, less leaves, and leaves become dull & thinner & curl up & wither, pale ... See below pic. of Munstead Wood when I put in too-acidic soil (leaves at pH 6 & and corn at pH 4):

Before deciding on gypsum or lime for a rose, I check the leaves with my finger. If it feels thin, withered, or curled up, it's a sign of too much acid.

If there are tons of thick & pale leaves, but no blooming, it's a sign of too alkaline, see below pic. of Radio Times large upper leaves, watered with pH 9 tap-water, plus NPK 10-5-4. Too much nitrogen & too alkaline. Note how the leaves got larger through high nitrogen application.

Munstead Wood is always pale, even in slightly acidic potting soil, it's throwing a 3 feet octopus cane from gypsum applied. The below pic. show plenty of calcium, but deficient in nitrogen, thus less and smaller leaves.

Gypsum provides calcium to make leaves, stems, and petals, but it DOES NOT initiate blooming. Munstead Wood didn't bloom until I gave it Coop Poop NPK 2-4-3, plus sulfate of potash.

Phosphorus helps with branching of roots, and branching of stems, so instead of "one-cane-wonder", you'll get a fuller-bush like Khalid's Winchester Cathedral. Note the branching below on Wise Portia with NPK 10-5-4 at early spring from winter-kill & zero leaves to a full bush & branching with phosphorus of 5, and nitrogen at 10 for larger leaves:

Sulfate of potash turns the switch on to pump out blooms, but it needs magnesium to slow down petal-forming, and calcium for solid petals. When only sulfate of potash/gypsum is given, like in a pot with zero magnesium, the blooms are formed too fast, you'll get "flat-out" blooms.

I also observe flat-out blooms and poorly formed in sandy-soil, like when I fixed my clay with a bag of sand, since Austin Eglantyne has wimpy root. Eglantyne has zillion of petals, sand isn't enough. Below is POORLY-FORMED Eglantyne bloom in a sandy & loamy soil, pic. taken Oct. 12 of 2013, not enough magnesium to slow down the knitting of petals:

My first bloom of Veteran was perfect: lots of swirl, more than 4" across. I topped that with alfalfa pellets NPK 2-1-2, with calcium & magnesium. Below showing blooms with high magnesium clay (Pink Peace and CPM), or high magnesium alfalfa in pots (red Veteran's honor and white St. Cecilia). Pic. taken this August 12, 2016.

Note the smaller bloom of St. Cecilia from a dense & compact peaty potting soil. Versus larger bloom on Veteran's honor from a looser & airy Schultz potting soil.

Magnesium is in dense & sticky stuff like CLAY, alfalfa meal, cocoa mulch, beans, corn, oatmeal, rotted manure, rotted grass-clippings, peat moss, dolomitic lime (10% magnesium and 25% calcium).

One site stated that magnesium is to form thick & glossy leaves. I notice that leaves become glossier with sticky alfalfa on top. When I watered Carefree Celebration (in a HomeDepot pot) with pea-gravel water ... leaves became glossy instantly from raising the pH with high magnesium water.

Below pic. is Sweet Promise in spring 2012 with before-winter fertilization of alfalfa meal & horse manure at combined-pH around 7.5. Note the glossy foliage from horses being fed with oats and alfalfa:

Magnesium slows down the knitting of petals, so you don't get flat-out blooms, you'll get more ruffles. Below pic. showing Sonia Rykiel (pink) and Evelyn (peachy pink) fertilized with high phosphorus chicken manure for larger blooms, plus my clay soil high in magnesium:

Potassium is vital for disease and pest-prevention & initiate enzymes. I use sulfate of potash to induce blooming, and to induce roots to do "acid-phosphatase", that's when roots secretes acid to draw phosphorus from soil.

But wimpy own-roots can't do that in pots, thus SOLUBLE phosphorus has to be supplied along with potassium as in MiracleGro NPK 20-20-20. From link below:

http://www.smart-fertilizer.com/articles/potassium-in-plants

Other symptoms of Potassium deficiency:

• Poor resistance to pests
• Weak and unhealthy roots
• Uneven ripening of fruits

Lime or gypsum is best applied at NEAR END OF BLOOMING, when the leaves become thinner & more susceptible to fungal infection, due to depletion of calcium and anti-fungal trace-elements like copper, zinc, boron, selenium. Below pics. show when to apply lime. I'll do another post on when to apply gypsum.

Shell lime (with trace-elements) is best applied for acidic conditions, some pics. to show when shell-lime is best applied: Pic below is NEAR END OF blooming on Mary Magdalene. This is the time to apply shell lime at 1/2 cup plus 1/4 cup sulfate of potash for disease-prevention. Note the leaves are smaller from depletion of nitrogen, so nitrogen should be given for new leaves.

Below pic. show the lower pale & thin & dull leaves of Dee-lish formed in acidic potting soil & acidic alfalfa tea. The upper darker-green & thicker leaves were formed when I added alkaline clay to the planting hole, along with horse manure (pH 8 with shell lime):

Below shows thinner & wilting of leaves from too much rain which leaches out both calcium and nitrogen from pots. Nitrogen mobility is a 10, it leaches out fast in pots.

The last pic. shows extreme acidity at pH below 5, with tons or rain (pH 4.5 in Chicagoland), plus acidic cracked corn (pH 4) and pine bark. This acidity killed many branches of Munstead Wood. At pH below 5, less nitrogen, calcium, and potassium are available. Also less sulfur & magnesium at very acidic range, thus the pale leaves. Note the leaves become thinner & curl up from acidity:

Wow....what a comprehensive tutorial Straw. Love the pics. Most of your roses have such a wonderful shiny foliage.... My roses had similar foliage in Mar / Apr but no more. Many of them have crinkled foliage.

Straw many of roses are simply outstanding. Love the photos...

Thanks so much for explaining about the timing of coop poop vs calcium and potassium. Do you apply extra potassium before blooms or just at the end in combination with calcium?

That last photo is what quite a few of my roses look like. Should I just use shell lime to slowly reverse the pH?

I wonder if the hydrated lime is good for anything or should I just return it? Suppressing weeds in a place where I don't want anything to grow?

Hi Aileen (totoro): Nursery sells the worst things. Like the time I sent husband to a local nursery to buy sulfate of potash. He called me on his cell-phone and said, "Do you want pot-ash?" I replied: "I don't want ash in a pot". I didn't realize that he meant potash. So he came there the 2nd time, and got Espoma "potash", it turned out to be Muriate of potash, or potassium chloride, with salt index of 116.2, that's the stuff we use to de-ice side-walk in zone 5a.

I was too lazy to return that, and used on my roses .. all blooms turned dark-brown at the edges, so ugly. So I ordered ORGANIC sulfate of potash, salt index of 43 on Amazon .. that worked great.

I would return that, it's too caustic & not safe. Wikipedia wrote on hydrated lime: "calcium hydroxide (portlandite) can dissolve in pure water to produce an alkaline solution with a pH of about 12.4. Calcium hydroxide solutions can therefore cause severe chemical burns. "

Calcium is best as in tiny-dose, slow-released. Down to Earth Oyster-shell flour on Amazon is sand-like, "Oyster shell provides a long-lasting, steady release of nutrients." Versus gritty oyster shell for chicken feed. Since your soil is acidic, the oyster-shell-flour will work faster than the gritty shell for chicken feed. But with my alkaline soil, I want the gritty lime for much slower-release.

Too much calcium will push down phosphorus, zinc, and iron .. so you'll let pale and stingy roses. With the oyster shell flour, I would use 1/2 cup along with 1/4 cup of sulfate of potash at mid-blooming for heavy-bloomers, when all buds are ready to pop open. If you wait until it's done blooming, then it's too late. By that time there will be calcium and potassium depletion from spent blooms, and nothing to support leaves, so either they drop, or become thin & susceptible to fungal infection.

Calcium moves down very slowly, that's why folks recommend fall-application of calcium or early spring to "sweeten" acidic soil. Potassium mobility is a 3, it moves down much slower than nitrogen (a 10 mobility). So potassium & calcium should be applied at mid-blooming when all buds are ready to open.

With stingy and pale roses, since there's very little blooming & very little acid produced by roots, alkaline lime is not needed, but sulfate of potash/gypsum combo will help roses to bloom ... their sulfur will activate "acid-phosphatase" for blooming.

For each flush: I estimate the weight of petals & leaves & branches .. if you pack 20 blooms plus stems plus leaves after pruning spent blooms .. it's at least 1/2 cup of calcium in there, plus 1/4 cup of potassium. If there's only 5 blooms, then much less acid is secreted, much less calcium to be replaced.

If one has tons of acidic rain, that will leach out calcium and potassium, especially in loamy soil. For acidic soil, liming in the fall, after roses are done blooming is best.

Thanks, Straw. I will try to return that bag of hydrated lime. I should just stick to ordering what I want from the Internet.

Before I tried kelp I bought Espoma Potash too. Will just use it for de-icing from now on.

Above is Oct. 12 bouquet with the largest blooms: Pink Peace, Tchaikovsky, and Stephen Big Purple. The rest are small blooms due to cluster blooming. Munstead Wood is the deep red, did get larger once it opened up completely. All are own-roots, except for Pink Peace (grafted on Dr.Huey).

The Pink Peace as own-root gave similar large blooms, but better scent. That own-root died in my zone 5a winter, so I had to get Pink Peace as grafted.

The nearby rose park has 1,200 roses GRAFTED on Dr. Huey, 1st year their Austins are amazing: lots of big blooms. But the 2nd year and onwards: Austins become huge and stingy. At first I thought cold zone damage the bud-union, but Seaweed in warm California also told me the same about her grafted-on-Dr.Huey: Austin Teasing Georgia becomes huge, zero blooms.

The problem with Austins grafted on Dr.Huey-rootstock: It's not a good idea to graft a water-hog on a drought-tolerant rootstock.

In contrast, hybrid teas are more tender thus best grafted for cold zone. I dug up Gruss an Teplitz to fix drainage and found a thick brown woody-root invading it. I was puzzled since there's no tree nearby. Then I realize that Pink Peace (grafted on Dr.Huey) invaded it from 11 feet away to steal water. So Pink Peace went past Poseidon and past Betty White to steal water from Gruss ... that's downhill where rain-water accumulates.

The last time I killed a decade-old Knock-out grafted on Dr.Huey: I found both own-root and Dr.Huey on it, except Dr. Huey extended 4 feet away to steal water from annual flowers. It took me 1 1/2 hour to kill Dr. Huey. Stan in zone 5a, Colorado reported that he found Dr. Huey came back to life after 5 years. That's hard to kill, unless one spend 1 1/2 hour getting rid of all the extending roots.

Rebecca (zone 4)

I have thrown out more Austin roses than most people will ever plant for one reason or another... Mostly because I didn't like the bloom and the growth. I have found that in my zone 4 garden, the own root planted deep do best. Grafted leads to huge growth with minimal bloom. Rebecca (zone 4)

Straw, you're a wealth of information on here! Thanks for posting this and the chicken manure info.

it is so hot down here still. 88 today and low tonight is 62. I haven't had rain in weeks but luckily the lake behind my house supplies my sprinklers. I still hand water sometimes though since I have all Austins and 2 meilland edens.

I tried the oyster lime (4 tbs) and sulfate of potash (1 tbs) since my roses got done blooming and the leaves do not look as good. Hopefully this will be a good vitamin. I'll have to report my results in a few days. I'm also thinking of watering with spirulina one last time this year before winter since I think my roses are missing some trace elements because of my fast leaching sand.

I am also going to try the coop poop, then compost and alfalfa hay on top "lasagna" method once I get a killing frost. I plan to clip off all the leaves and do a winter pruning since some of my roses need a little shaping.

lastly, I noticed when I was scratching in the lime and potash, the soil would wash out from the surface and form like a hole in my sandy loam. It's very bizarre to me and I tried to google it but I didn't come up with anything. It's like there is air pockets forming around my roses' rootballs when I water. I don't get how it's happening. It keeps lowering the level of the soil around the rose crown. So I really need to add more soil or organic matter around my roses. I just purchased a haws watering lance (so excited!!) from lee valley to hopefully fix this problem by using a gentler spray of water (even though my hose has a shower setting). Do you know what's happening? And how to fix?

Filly: I saw the same in Cloudert Soupert's root when I dumped a bucket of water, which made a hole and exposed the root. I made that spot loamy with a bag of sand.

THAT DOESN'T HAPPEN WHERE IT'S DENSE CLAY. Clay doesn't sink, but sand does. Magnesium is what "glue" soil together, so anything high in magnesium like clay is best. There's a poster "fragrantcutter" in Rose forum that fixes her sandy soil in CA with Bentonite clay and get the best blooms.

http://www.genclermining.com/tags/potassium-bentonite

There are 3 types of Bentonite: sodium, calcium, and potassium. "Bentonite usually forms from weathering of volcanic ash, most often in the presence of water. However, the term bentonite, as well as a similar clay called tonstein, has been used for clay beds of uncertain origin. For industrial purposes, two main classes of bentonite exist: sodium and calcium bentonite."

**** From Straw: clumping kitty-litter contain calcium-bentonite and can be used in the garden, just have to read the ingredients to make sure that it's Calcium-Bentonite, rather than sodium bentonite (high in salt).

Calcium Bentonite is very expensive, and organic matter high in magnesium like alfalfa meal is cheaper. Alfalfa meal "glues soil" together well, same with rotted manure, compost, and grass clippings. Decayed greens tend to "glue together" due to high-magnesium.

I have 14+ pots this year, and I use 5-gallon bucket to dump water into the pots. That always create a hole, except for the pots where I topped with grass-clippings or alfalfa pellets to buffer the force of water. So I put grass-clippings & zero-salt- Standlee alfalfa pellets first, then red-lava on top to buffer the force of watering.

Below is a link that shows how to add clay to the garden:

http://homeguides.sfgate.com/add-calcium-bentonite-soil-83607.html

Sandy Soil: Put 2 pounds of calcium bentonite in a bucket and add 2 gallons of water. Leave for 24 hours.

Apply a wetting agent to about 2 square yards of ground, using a wetting agent applicator.

Stir the calcium bentonite and water vigorously with a stick. Leave the mixture to settle for 30 seconds before pouring into a watering can. Leave any lumps in the bucket.

Water the calcium bentonite suspension into the ground, allowing time for it to penetrate before applying more, to prevent runoff.

Mix remaining lumps with more water and pour the suspension onto the garden beds. Scatter any lumps that don't break down across the soil.

Thanks straw I will have to try adding clay! I have noticed that the alfalfa does glue up the top soil when I put them on top of my roses

Fily: Magnesium sulfate (Epsom salt) is useful for sandy soil ... magnesium is less available in sandy soil. My sticky & heavy clay soil is tested exceedingly high in magnesium.

Epsom salt crystallizes after application, so it "glue-up" soil particles to enhance water-retention and prevents soil-erosion on top. But it's still inferior to organic matter, since Epsom salt has a "drying-effect" ... but works great to kill pests & insects' larvae on soil surface.

http://www.dummies.com/home-garden/gardening/flower-gardening/how-to-fertilize-your-roses/

"Magnesium: Many rose growers swear by magnesium applications, but only when the soil is deficient in magnesium. Magnesium sulphate — called Epsom salts in drugstores — is the form that’s usually applied. This chemical helps intensify flower color and increases production of new flowering canes. Water in 1⁄4 to 1⁄2 cup per plant once or twice a year."

Just wondering if those of us who tried coop poop last year had good results? I think it did not have enough nitrogen for me so I had to supplement with fish emulsion. But who knows last year was my first time dealing with Midge.

Totoro: You are right that Coop-poop doesn't have enough nitrogen at NPK 2-4-3, with 8% calcium and 0.6% magnesium. When I used Coop-poop, I mixed with blood meal NPK 12-0-0. The growth was ideal with lots of blooms.

Then I found Holly-Tone at NPK 4-3-4 cheap on Amazon, a huge 36 lb. bag for $34 (late summer), so I applied that, and my roses became too tall, like 7 feet tall James Galway and Dee-lish was taller than me with less blooms. Holly Tone has a small amount of sulfur to dissolve the fertilizer better with my alkaline-tap-water.

I find that acidity of rain-water and soil STUNTS ROSES more so than the % of nitrogen. Holly-Tone has nitrogen of only 4, but that was used with my alkaline-tap-water (pH near 9), and the growth was vigorous & too tall.

In contrast, I pile up ACIDIC grass-clippings in spring and that STUNTED roses, despite blood meal with nitrogen of 12. ACIDIC grass-clipping did the same to roses in pots. Organics like leaves & grass-clippings can turn extremely sour with acidic rain water (pH 4.5 here). It's like piling up "sour Kimchi" on roses & burn and stunt their roots.

My roses were much more vigorous in spring when I winter-protected with ALKALINE horse manure (pH 8), or ALKALINE wood-chips (NOT pine-bark). A few University Extension documented that wood-chips (hard-wood) break down to alkaline pH, but pine-bark (soft-wood) doesn't break down as rapidly and stay acidic for a long time.

Nitrogen leaching is common with abundant spring-rain, so I used a much higher nitrogen. Looking back, my best spring-flush was with NPK 10-4-5 early spring. Less nitrogen is needed for summer and fall flush since there's less rain. Blood meal takes at least 1 month to be activated so I apply organic-nitrogen very early spring.

I've never used it, totoro, but re-reading the last entry makes me wonder if applying epsom salts could help with that, as well. I always used to give New Dawn a dose in spring until I read it's not necessary. Let's hope the steps we took for it last year and this spring help.

Vaporvac: Fantastic suggestion, YES, EPSOM SALT DOES HELP WITH PESTS. Epsom salt is magnesium sulfate. If you boil Epsom salt in water, then flood the top 1/2" soil with this hot water, it will cool down, and CRYSTALLIZE to kill all midge's larvae. I posted a recipe here a few years ago on how to make EPSOM crystals. As long as the hot-epsom-salt water doesn't seep down below 1/2", it won't hurt roots, but kill any pests on top.

In my decades of growing roses, I caught midge only one time on 2 roses .. that's because I topped them with fluffy-potting soil, rather than using my sticky-alkaline-clay (tested exceedingly high in magnesium). Epsom salt is magnesium-sulfate, often deficient in sandy, or loamy & acidic, or potting soil.

Thanks so much Straw! I never heard about that approach to midge.

I am trying the cover the ground approach right now, but may need to escalate my interventions.

totoro, that's an approach mentioned for other insects, not midge, but I was suggesting to use it for that based on Straw's comments above that it dries up insect larvae...

"Epsom salt crystallizes after application, so it "glue-up" soil
particles to enhance water-retention and prevents soil-erosion on top.
But it's still inferior to organic matter, since Epsom salt has a
"drying-effect" ... but works great to kill pests & insects' larvae
on soil surface."

Since I'm in the midst of doing my beds now with amendments I'm thinking of trying this. Of course, it won't be a definitive answer since it's a two variable experiment, but I'm going to suggest it to Jim in Pa, since he doesn't want to use a covering. Straw, do you remember the ratio of Epsom salt to water? If not I'll try to find your post. Do you think I should apply it as the final layer? I wonder if diatomaceous earth would work as well.

I also find your comments on having some luck using pure clay on top of your soil interesting as perhaps the larvae can't work their way into the soil and thus die. Peter Schneider hypothesizes that they like manure. Perhaps what he's seeing is that they can be more mobile in it, similar to Straw's observation with fluffy loamy soil.

Here's the recipe from Gardenknowhow site:

https://www.gardeningknowhow.com/plant-problems/pests/pesticides/epsom-salt-for-pest-control.htm

"Epsom Salt Solution Insect Control – A mixture of 1 cup Epsom salt and 5 gallons of water may act as a deterrent to beetles and other garden pests. Mix the solution in a large bucket or other container, and then apply the well-dissolved mixture to foliage with a pump sprayer. Many gardeners believe that the solution not only deters pests, but may kill many on contact.

Dry Epsom Salt – Sprinkling Epsom salt in a narrow band around plants may be an effective means of slug control, as the scratchy substance abrades the “skin” of the slimy pests. Once the skin is effectively roughed up, the slug dries up and dies."

From Straw: The epsom-salt-solution spraying is more effective than the dry-epsom salt for MIDGE. Why? Cornell University research on midge showed that midge larvae needs a certain % of moisture to hatch. I posted that research in 2014. Midge doesn't like it too dry nor too wet. One recommendation was to flood the area.

My high-magnesium clay is SOAKING WET when it rains, but BONE-DRY when it's dry, so midge larvae can't hatch. Epsom-salt (magnesium sulfate) is neutral pH, so it won't hurt plants if you flood only the top 1/2" of soil. But if too much Epsom-salt solution gets to the root-zone, it'll make soil too dense for root-growth.

Thanks again. Don't know why I'm just now seeing this. I'm going to pm Jim with this post. He has observed in his own garden that his midge seemed to decrease in dry conditions. Of course, he lives in a place with a lot of rain so it's difficult.

If I put wood mulch under roses Rose Midge appears to be much worse than if I just let the soil under and around roses bare... Our soil gets wet when it rains but dries out fairly quickly a couple inches down when it is dry outside if soil is left bare under roses...

Epsom Salts: Sounds like this could be a weapon against Rose Midge... How would you keep it from going to deep though? ( I'm guessing put in a water can that sprinkles like rain and apply just alittle to soil surface? Anyhow a idea to explore! Thanks Straw and vaporvac....You two take care....

Jim, have you tried the topical solution you mentioned in the Rose forum? It's surprising that diatomaceous earth didn't do anything in the studies. I also wanted to say that while there's no news on the Midge front this year, the landscape fabric does seem to have prevented a sawfly infestation.

After getting rose midge I'm kinda more fond of rose slugs now...lol...No I haven't tried any topical solutions...Guess I'm just doing one thing at a time to see if I can put a organic dent into these beasts...lol

That's so true, Jim!!! I'm taking my victories where I can find them. Most everything else seems like small potatoes now!

bump up for reference.