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What else can I do for my roses?

Posted by boncrow66 none (My Page) on
Mon, Aug 4, 14 at 9:36

I have been posting over on the rose forum but have a question about what to feed my roses. I typically give each of my roses half a cup of a blood and bobe meal combo in the spring and water in with 2 tablsespoons of Epsom salt in a 2 gallon watering can. I don't have mulch around my roses either. My roses are all blooming well but I'm just wondering if there is something else I can do. I also about once a month feed wth miracle gro. I live in hot and humid se Texas and some of my roses do get black spot, I have heard if you sprinkled corn meal around the roses that this will help, is this true? Thanks for any info. I really want to to keep it simple and not to complicated.


Follow-Up Postings:

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RE: What else can I do for my roses?

Well I want to say if its not broke don't fix it...lol
BUT that Miracle Gro your using is not feeding the soil its more like a candy bar for roses (quick fix)...

Maybe instead try using some organic rose or plant tone every two months next year and see what happens.
It says feed once every month on the package but I think that is overkill...

I'll let Strawberryhill tell you about Corn meal...
I looked in some notes I had and I did try Corn Meal back in 2010 but I had no luck with it helping Blackspot here...

This post was edited by jim1961 on Mon, Aug 4, 14 at 10:03


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RE: What else can I do for my roses?

Hi boncrow66: If you have clay soil, then skip Epsom Salt. It's high in salt, plus high in magnesium. Magnesium is what makes clay soil sticky. My clay soil is tested exceedingly high in magnesium. That deficiency is rare, except in sandy soil.

I pH-test corn meal, it's acidic like peatmoss, pH around 4. I tested MG soluble fertilizer for roses, rose immediately break out in BS from the salt of the fertilizer. Such high dose of chemical can be stressful for plants. Plus the high phosphorus in MG-soluble make zinc less available. Zinc is the strongest antifungal nutrient, suppressing that, and you'll get diseases.

Since you already give roses nitrogen via bloodmeal, and phosphorus/calciuim via bone meal in spring ... what's missing is BALANCED fertilizer like Jim suggested. My best result is with Tomato Tone, rather than Rose Tone, because you get higher NPK 3-4-6. The higher potassium number of 6 helps with hot & dry weather in Texas. Potassium and calcium are known to help with drought-tolerance, see below link.

Here is a link that might be useful: Abstract on potassium & calcium helps with drought

This post was edited by Strawberryhill on Mon, Aug 4, 14 at 11:34


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RE: What else can I do for my roses?

Hi Boncrow66: I forget to answer your question: "I live in hot and humid se Texas and some of my roses do get black spot, I have heard if you sprinkled corn meal around the roses that this will help, is this true? "

Let's start with the soil research, the work of Sweden and United Kingdom together: ""ABSTRACT: The influence of pH on the two principal decomposer groups in soil, fungi and bacteria, was investigated. This experimental location provides a uniform pH gradient, ranging from pH 8.3 to 4.0, within 180 m in a silty loam soil. .. The growth-based measurements revealed a fivefold decrease in bacterial growth and a fivefold increase in fungal growth with lower pH. .. Below pH 4.5 there was universal inhibition of all microbial variables."

That means as the pH increases to 8.3, there will be plenty of beneficial bacteria, and less pathogenic fungi. As the pH decreases toward 4.5, less bacteria to fix nitrogen, and more fungi like black spots, rust, and mildew. BELOW pH 4, too acidic, like cracked corn and peat moss, there won't be any bacteria nor fungi. I tested dusting WHOLE-GRAIN corn meal ON THE LEAVES ... it worked because at such acidic pH of 4, no fungi can grow.

Dusting corn meal on the ground? It depends on one's soil and climate. Corn meal worked great on Frederic Mistral last year, because my soil is rock-hard alkaline clay, pH 7.7. Being acidic, corn meal neutralized my high pH, to release nutrients. Fred became dark-green with healthy leaves. But ACIDIC corn meal doesn't work for Jim, because he has high-rain (pH of rain is 5.6), plus acidic soil. Too acidic soil will lower calcium and potassium, necessary for disease-prevention.

I already tested corn meal ON THE SURFACE of acidic potting soil (pH 6.5). Corn meal, at pH 4, LOWERED the soil pH further, and worsened the BS.

My answer: dusting very acidic corn meal on leaves, yes, it works. Dusting the ground with corn meal? Yes if your soil is alkaline. No, if your soil is acidic with tons of rain, that will lower the soil pH too much. Now my Frederic Mistral rose has tons of blackspots, plus very pale with mulching with bagged cow manure (from the salt & quick lime in manure, or the high phosphorus).

Below link shows the effect of soil pH on the growth of bacteria and fungi. Picture is my Frederic Mistral rose last August, 100% clean with corn meal on the ground, plus dusting leaves with corn meal. WHOLE GRAIN Corn is high in zinc and copper, two strongest antifungal nutrients.

Here is a link that might be useful: Contrasting soil pH effects on fungal and bacterial growth


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RE: What else can I do for my roses?

Thanks strawberryhill and Jim for all the info. This is like chemistry class lol. I had no idea it could get so scientific but it makes sense when you consider all the factors like the Ph of you lt soil, etc. I live in a pat of se Texas that gets plenty of rain, so sounds like corn meal on the ground wouldn't work for my BS. I have just taken it as a fact of life that my roses will eventually get some BS at some point. I have never had my soil tested so I guess that would be something I would need to have done. But until I am able to have that done let me make sure I have this straight, I should keep on adding my blood/bone meal in the spring and then add rose or tomatoe tone, preferably tomatoe, once a month or every 2 months? There is a local nursery that sells their own organic rose food with cotton seed mill, bone/blood meal and Epsom salt all mixed. They mix it according to how many roses you have. Any thoughts on that mixture? I have only heard good things about the tone products so I am leaning towards using that.
Strawberryhill your knowledge is very impressive and I appreciate all your time and effort that obviously goes into your responses to posters questions.


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RE: What else can I do for my roses?

Hi boncrow66: Thank you for your kind comment. My B.S. is in Computer Science, minor in Chemistry. I also took Microbiology, Biochemistry and all the pre-med classes. Since you have high-rain, once a month of Tomato-Tone is best. Espoma Tomato-Tone is higher in potassium, and potassium leaches out during rain.

Cottonseed meal is acidic, Epsom salt is salty ... not the best mix. Rub soil between your fingers, if it's sticky like mud, then there's plenty of magnesium, no need for Epsom salt (magnesium sulfate).

Balanced fertilizer is best, if Tomato-Tone works for you, then skip the blood meal/bone meal combo ... that has zero potassium. What helps with high-rain fall in spring is 1 cup of dolomitic lime (calcium plus magnesium) sold as Espoma garden lime.

If your roses are grafted on Dr. Huey, with heavy rain, some gritty lime around rose bush helps because Dr. Huey's rootstock likes it alkaline, and break out in BS with too much rain. pH of rain is 6 to 5.6, and pH of garden lime is 9. That would balance it to slightly alkaline, which is best for Dr. Huey's rootstock, plus to prevent diseases.

Take the black fungi on my shower curtain: I solved the problem by either spraying with diluted vinegar (pH 3 to 4), or killing the mold with baking soda, pH near 9. My Radio Times rose is a stunt, BS-fest last year. This early summer with 1-month-long rain, I put 1 cup of gritty lime. It DOUBLED in height, clean & healthy, plus lots of blooms. I gave it chicken manure NPK 5-3-2 early spring, that's all, so the doubling in height was from the dolomitic lime alone. Calcium helps with root-growth. It's next to a tree, and calcium helps with drought in this hot & dry August, with temp. near 90 degrees, see below pic. of Radio Times, healthy, despite being next to a tree, and invaded by tomato:

Below is a link from Texas A & M University Agriculture Extension entitled "Using Soluble Calcium to Stimulate Plant Growth".

Here is a link that might be useful: Texas A & M research on soluble calcium


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RE: What else can I do for my roses?

Strawberry thanks for all the good advice and keeping it simple for me lol, chemistry is not my fortay lol. I think I got it down now. I am going to buy some gritty lime and see how that works out for me. Does it actually say gritty lime on the bag? And does it go on the leaves or the ground? I am pretty sure all my roses are own root, I have several Austin's, a SDLM, zephrine, cl pinkies, strike it rich, Nacodoches and 2 Don Juan, a pink and red, all purchased at Chamblees. And one more question, how often do you use the gritty lime? There is so much to learn!


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RE: What else can I do for my roses?

I spent years trying different things for Blackspot... I would devote one entire season to something or a couple things. I have not had one thing work for me...lol

We get lots of rain and we have dew problems at night so leaves are always wet. So anything applied washes off the leaves or soil. And you have to keep re-applying then 90% of the time it made things worse.

Now your climate, blackspot pressure and soil are different so who knows certain things may work for you...
That's why I do encourage experimenting...

This is a pic of our Mister Lincoln rose leaves. These leaves started getting wet from dew about 10:30pm last night... This morning at 9:30am they were still wet...
A disease breeding ground my friend...lol

 photo IMG_1293_zps14214241.jpg


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RE: What else can I do for my roses?

Jim1961, my climate can be very humid and steamy, it can rain during the night and then when he sun comes out it feels like your in a sauna the rest of the day, not good for black spot and makes for really bad hair days lol. I'm willing to experiment but only to a certain point. Right now I am able to keep things under control by picking off the leaves and keeping the ground clean. My red Don Juan is the only one that has defoliated so far. And I know that it will get better in the fall when the weather won't be so humid.


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RE: What else can I do for my roses?

Bad hair day....LOL (That made me laugh) lol
Yes sounds like BS can be a problem in your climate too...

I quit picking BS leaves off a couple years ago because there was just way to many...lol
Most of the time almost all the leaves would fall off so I removed all those rose bushes and am now looking for better BS resistant ones... I may have to create some raised beds also... Slow process but I'll get there!


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RE: What else can I do for my roses?

Hi Jim: thanks for posting that pic... what a battle it must be for prolonged wetness in your climate. I admire your persistence in growing roses. More than a decade ago, my garden was acidic clay, I lost the battle with blackspots, and gave up on roses. Then I planted 26 trees, that's way-more trouble than roses. The morale: Roses are easiest plants if BS is solved. Trees are tremendous work !!

Hi Boncrow: The garden lime is grittier than ground-limestone, so I call it "gritty lime", but it's Espoma Garden Lime, sold at HomeDepot for $5 per 6.75 lb bag. On the bag it stated the % of calcium and the % of magnesium. The ground limestone is fine like flour, sold at my local Menards cheap $4.49 for 50 lbs. I don't recommend that finely ground stuff, since it's dusty and raise the pH too quickly.

Pelletized lime is more expensive, because it's coated with clay in small pellets, to make easy to spread via a lawn-spreader. Pelletized lime is slow-released, sold for $13 per big bag.

Don Juan is bred in U.S.A., and can take alkalinity. A bit of garden lime ON THE GROUND to counter-act the rain is OK. I haven't tried dusting the leaves with ground limestone at pH 9 ... might worth experimenting, considering that the salt index of lime is LOW, at 4, versus very salty baking soda. Despite that, folks use baking soda (sodium bicarbonate) to spray leaves for B.S. Baking soda pH is slightly less alkaline than lime. Honestly it's a pain to spray anything, including my moldy shower curtain. It was so much easier when I threw corn meal on roses' leaves.

Garden lime IS NOT BEST for some own-root Austins that prefer it acidic, such as light-green leaves Charles Darwin, Graham Thomas, Teasing Georgia, W.S. 2000, A. S. Lad, and Jude the Obscure.

In contrast, Crown. P. Margareta, Radio Times, Golden Celebration, Evelyn, Mary Magdalene, Wise Portia are the few Austin roses that benefit from garden lime, but the rest of my own-root Austins hate that stuff, become very pale, esp. own-root Jude the Obscure. French Romanticas love that garden lime, since they were bred in France, a more alkaline soil and hotter climate, with gypsum deposits.

Espoma bag says garden lime lasts for 4 weeks. I would use it in spring with heavy rain, since Frank Gatto, owner of a rose-nursery recommended 1 cup of lime per rose bush in spring, in his high-rain PNW.

If too much lime is used, it will make leaves pale and drive down potassium. I applied 1 cup of lime in spring for Radio Times ONLY ONCE, and that rose is clean for the rest of the year, there are still some remains on the ground, since it's slow-released gritty lime which I got free from nearby quarry.

This post was edited by Strawberryhill on Mon, Aug 4, 14 at 16:26


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RE: What else can I do for my roses?

Yes I have been very frustrated in the past watching leaves all fall off rose bushes BUT recently instead of dwelling on the leaves I just enjoy the blooms etc...

I know I'll have to probably replace Thomas Affleck so I'll just enjoy his blooms while he's here and will move on to another rose experience next year... Hopefully good ones with leaves staying on the bushes...lol


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RE: What else can I do for my roses?

Lime helps with nitrogen and potassium absorption. For that reason, farmers put lime first, then fertilizer on top to prevent leaching of nitrogen. Lime is applied together with sulfate of potash. Lime is alkaline, pH over 9. Sulfate of potash is acidic, with 23% sulfur. Those two neutralizes each other.

See below link on farm-report of soybean yield, where pelletized lime TOGETHER with potash gave the highest yield at 51.5 bu./acre., which beat fungicides alone at 49.6 bu./acre.

Since I have 50+ roses, it would be costly to use Tomato-Tone monthly for all of them. So I use Milorganite NPK 5-2-0, at $10 for a HUGE bag, it's less stinky than chickity-doo-doo, NPK 5-3-2 also cheap at $8 for a 25 lb. bag. The drawback of both is low in potassium. That's why I buy granular sulfate of potash to supplement the above.

Potassium mobility is a 3, compared to nitrogen mobility of 10, and phosphorus mobility of 1. Both nitrogen and potassium leach out with rain most in sandy soil, somewhat in loamy soil, and very little in my heavy clay. My experiments with sulfate of potash or high-potassium-red lava rocks improved blooming considerably.

My soil is alkaline clay, thus the phosphorus in heated sewage waste like Milorganite is more soluble when applied on top than bone meal in Tomato Tone, which I save for the planting hole. According to U. of Colorado, bone meal is not utilized when the pH is above neutral, such as lime at pH 9.

For that reason, Lime doesn't go well with bone meal. Also Tomato Tone once a month, but NOT with lime, since at pH above neutral, the bone meal component of Tomato-Tone can't be broken down to be used by plants. Tomato-Tone NPK is 3-4-6.

Here is a link that might be useful: Pelletized lime and potash in soybean crop


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RE: What else can I do for my roses?

Strawberryhill thanks so much for all the info! I am for sure going to use tomatoe tone starting next spring on my roses. I have 3 Austin's, Evelyn, golden celebration and heritage. Heritage has no BS , Evelyn has had very minimal BS but GC has had BS the most. I agree with Jim, I am going to worry less about BS and just enjoy the blooms my roses give me:).


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RE: What else can I do for my roses?

I just contacted David Zlesak from the University Of Wisconsin. Coordinator of the Northern Earth-Kind® Rose Trials (purpose is to identify well-adapted, low maintenance landscape roses for there northern Midwest region).
Anyhow David Zlesak has studied Blackspot for many years and uses scientific equipment and information.
I asked him some questions on Blackspot and I hope he gets back to me...


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RE: What else can I do for my roses?

Hi Jim: I would love to hear more about B.S. from David Zlesak, please inform. Thanks.

Hi Boncrow: I came to the same conclusion today, while I see the most deep-color & big and well-formed blooms on my Frederic Mistral rose. The best blooms in 3 years, despite super hot & dry August. I gave Fred bagged COW manure recently, and it broke out in B.S.

I suspect high phosphorus in the cow-manure is the culprit, since my roses also broke out in B.S. and became pale the last time I tested high-phosphorus chemical fertilizer. In Texas A & M Extension research: Excessive phosphorus cause zinc and iron deficiencies. My Fred grew pale leaves (iron deficiency) after cow-manure application. The breaking out in B.S. is due to zinc deficiency. Zinc is the strongest anti-fungal agent, next is copper, then calcium.

However, the phosphorus in cow-manure deepened the color of my blooms, and the quality of blooms is so perfect, that I don't even bother scraping the manure off. Here's an excerpt from eHow on phosphorus: "Bloom busters are high in phosphorus and are also referred to as super phosphorus foods. They can increase flower yield and are used by exhibition and champion growers for bigger, brighter flowers."

I also put that cow-manure on Bolero: the blooms are huge, with many petals, plus it acquired a pink-tinge ... versus normal white. Bolero also came down with black spot. The article on how to turn hydrangea from pink to blue advised NOT to use high-phosphorus fertilizer, because high phosphorus shifts the color to the red-zone.

I scraped off the cow-manure from Stephen Big Purple, but the effect on the blooms was awesome: the biggest, and most petals blooms in 2 years. When I give roses high potassium such as sulfate of potash, they pump out more blooms, but the quality is poor: less petals, and bleaching out of color. The advantage of cow manure is phosphorus, plus calcium, plus trace elements to give the best quality blooms possible.

Below is a bouquet showing the initial effect of high-phosphorus cow-manure. Today Fred's blooms are even deeper pink, bigger, and more petals despite dry and hot August. For that alone, I over-look the black spots. Picture was taken last week:

Here is a link that might be useful: Texas A & M Extension on high phosphorus


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RE: What else can I do for my roses?

Excess of one nutrient induce deficiencies in others: such as excess nitrogen induce deficiency in potassium, thus less blooming. Excess of calcium induce deficiencies in: potassium and boron. Excess in phosphorus (as in manure & bloom-booster) induce deficiencies in zinc and iron.

Here's an excellent link on nutritional deficiencies in tomato plants, which lists boron deficiency as "Small leaves; heart rot (corkiness); multiple buds." Other sites described boron deficiency as leaves curling upward. The tomato which I put too much gypsum (calcium sulfate) in the planting hole has leaves that curled up.

Iron deficiency as "Yellow leaves; veins remain green." This occurs in young new leaves, versus nitrogen deficiency: yellowing older leaves.

Manganese deficiency as "Leaves mottled with yellow and white; growth stunted." I have plenty of manganese deficiency in my pH 7.7 clay. Other site described purplish spots, which I see in my rhododendrons.

Zinc deficiency as "Small, thin, and yellow leaves, low yield."

Other sites described Copper deficiency as soft, and weak branches. Zinc, copper, and calcium are the 3 antifungal trio which help to make leaves thick & strong.

Magnesium deficiency as "Yield down; old leaves white or yellow." Magnesium deficiency is rare, only in sandy soil. My heavy clay is tested exceedingly high in magnesium.

Calcium deficiency as "Growing points of plants damaged". Haifa site listed calcium deficiency as wilting of leaves' tip: "Plants under chronic calcium deficiency have a much greater tendency to wilt than non-stressed plants.

Sulfur deficiency as "Light green to yellow leaves; growth stunted." Haifa site stated "The veins and petioles exhibit a very distinct reddish color." Correction with rain water or gypsum.

Potassium deficiency is described by Haifa as "marginal chlorosis, progressing into a dry leathery tan scorch on recently matured leaves. ... increasing interveinal scorching progressing from the leaf edge to the midrib as the stress increases ... most of the interveinal area becomes necrotic, the veins remain green and the leaves tend to curl and crinkle."

Below pic. is how pale Fred became after application of cow-manure last month, then Fred broke out in black spots for the 1st time in 3 years, thanks to the high phosphorus. High phosphorus induce zinc and iron deficiencies, causing both pale new leaves, and BS-prone. Zinc is the strongest anti-fungal for plants, with copper and calcium trailing behind.

Here is a link that might be useful: Pictures to identify nutritional deficiencies

This post was edited by Strawberryhill on Mon, Aug 4, 14 at 22:49


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RE: What else can I do for my roses?

I hung out in the soil forum for a while, and someone with a garden heavily fertilized with cow manure for years, submitted a soil test, it came back with skyrocketed high-value in phosphorus ... he asked the soil forum how to solve that problem.

Another person in Soil Forum mentioned that his phosphorus and potassium were initially low, but after years of frequent compost-application, the soil report came back high in both phosphorus and potassium.

My alkaline clay, pH 7.7, is tested by EarthCo. to be exceedingly high in magnesium, barely adequate calcium, most deficient in phosphorus, and marginally deficient in potassium.


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RE: What else can I do for my roses?

Jim I can't wait to hear what your contact has to say about black spot.

Strawberry, I appreciate all the info and plan to put into use in my garden. I am going to have to re-read this thread and make notes this weekend.


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RE: What else can I do for my roses?

Hi Boncrow66: You help me to solve the questions about the bagged cow manure from Menards, and WHY it made my 4 roses break out in black spots. It rained last night after more than a week of dry & hot weather. My Frederic Mistral rose got the most cow manure: the whole bag. Fred was clean for 3 years, now lost 1/2 of its leaves after last night rain.

I check the chemicals added to cattle feed, see link below. A HUGE amount of phosphorus is added from 4 sources: Ammonium Poly-phosphate, Monoammonium phosphate, Phosphoric Acid, Phosporus (P). Plus variety of sulfur: Ammonium sulfate, sulfuric acid, sulfur. Plus salt: urea, salt, iodine. Also manganese.

The sulfur amount is troublesome ... I induced BS many times by lowering soil pH. Manganese is known as a fungal-promoter. Cattle feed is the perfect recipe for fungal growth: high phosphorus, sulfur, salt, and manganese.

Fred is severely affected since it has the most loamy soil: I fixed that hole with 1 bag of sand. Mary Magdalene was the cleanest rose in my garden, 100% clean even in early summer 1-month-rain. Now Mary broke out in BS, after being topped with 1/2 bag manure. Mary's blooms become pinkish & deeper color, very pretty. High phosphorus shifts the color to the red-range, is used to turn hydrangeas darker pink.

Bolero blooms become pink, rather than normal white. Bolero also broke out in BS from cow-manure, but less, since the soil is rock-hard clay, phosphorus moves down less. Cow-manure has higher phosphorus, salt, and manganese than horse manure. Manure' phosphorus is SOLUBLE for IMMEDIATE uptake by plants, versus slower-released phosphorus in bone meal, which needs acidic pH to break down.

Without Texas A & M document on how high phosphorus induce iron and zinc deficiencies in plants, I would NOT be able to solve this puzzle. Zinc is the strongest anti-fungal agent for plants. Both zinc and copper suppress fermentation in wine-making, versus manganese promotes yeast and fungal growth.

Fred looks so bad, after 1/2 leaves dropped. I will have to scrape off the cow-manure to give to my heirloom tomatoes. Tomatoes do best with high phosphorus. Our bumper crop was when I used 6 bags of cow-manure on my tomato garden: the largest fruits ever.

Here is a link that might be useful: Additives in Cattle Feed


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RE: What else can I do for my roses?

David Zlesak contacted me today and told me he was at a conference. And when he returns he will send me studies they have done on Blackspot.


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RE: What else can I do for my roses?

Hi Jim: Thanks for the info. I do lots of experiments with my 50+ roses, since my zone 5a make roses so small, which I can dig up and fix the soil. Plus roses lose all their leaves in my winter, so I don't care.

Below is the best link with great pics. to identify nutrients deficiencies in plants. My neighbor's tomatoes fertilized with soluble chemical high NPK look awful in this hot August .... lower half of plants are brownish & wilted, most likely from the salt in fertilizer. His tomatoes beat mine in spring growth, but mine are healthier than his in hot summer, thanks to using low-salt organics.

Here is a link that might be useful: Best link with pics to identify plants' deficiencies

This post was edited by Strawberryhill on Tue, Aug 5, 14 at 16:42


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RE: What else can I do for my roses?

I have noticed that when I apply my alfalfa tea, shortly afterwards the roses have a BAD case of BS. I do spray with chemicals, Bayer Disease, Banner Max, Mancozeb on time and starting mid July I begin battling the BS.


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RE: What else can I do for my roses?

Hi Kentucky Rose: You are right in your observation. Years ago when I researched on making alfalfa tea, another person made the same observation: Roses grew, but broke out in B.S.

This year I test Alaska Pennington pellets, NPK 4-6-6, ingredients are mainly alfalfa meal & fish bone meal & sulfate of potash. Roses break out immediately from B.S. , esp. when used with my rain-barrel water, pH 6 in my Chicagoland. Rain water is acidic, more so in the East coast, with reported pH of 5.6.

Did you use alfalfa meal to make tea, or alfalfa pellets (the type for bunnies)? Alfalfa meal pH is 5.7, quite acidic. Alfalfa pellets, the type for bunnies, also has salt and sugar via molasses added. Fungi loves sugar. One nursery recommended lowering soil pH by pouring a can of Coke into the soil. The fermentation of sugar releases acid. When the pH becomes acidic, that promotes fungal growth.

I have Duchess de Rohan in the ground, the worst spot possible: poor drainage wet clay, shaded by trees in the summer, now down to 1 hour of sunshine. It gave a great spring flush before the trees leaf out. Plus poor air flow, yet it's 100% clean. Why? I broke up my heavy pH 7.7 clay with gypsum (for calcium). Then I watered with sulfate of potash (for potassium), plus putting red-lava rocks for extra potassium. Picture below taken today, after yesterday's 12 hours of rain:


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RE: What else can I do for my roses?

I notice the same with Comte de Chambord, 100% clean until the end of its 2nd flush. I watered that with Pennington tea, NPK 4-6-6. More rain, and it broke out in B.S. Roses use lots of potassium & calcium to produce those petals, and both are depleted at the end of flush.

I have a second Comte de Chambord, which I planted in the front. I put gypsum in the planting hole, so I balance that chopped up banana peels for potassium, plus sulfate of potash. That one doesn't have B.S. The ratio of NPK in fertilizer, and the pH of the water determines how clean a rose is. When the pH of water is acidic like rain, plus high phosphorus fertilizer, it's a BS-fest. When the pH of water is alkaline tap, plus enough calcium and potassium, and less phosphorus, then roses are clean.

I bought a second Duchess of Rohan, grow in a pot. It has fluffy potting soil, more sun, yet break out in black spots. Why? I forgot to put gypsum in the potting soil, so I threw gritty lime (pH 9) on top. But I forgot to balance out the calcium with potassium. Instead, I used Pennington tea (with alfalfa meal), NPK 4-6-6. See picture below of the SAME ROSE, in an ideal location, fertilized with higher phosphorus ratio, plus acidic tea made from alfalfa meal. this second Duchess de Rohan is a BS-fest, picture taken today, after yesterday 12-hours rain. The dry granules on top are Encap dry compost made from leaves and cow manure, sufficient phosphorus, but low in potassium. Potassium is necessary for blooming, drought-tolerance, and disease-prevention ... needed in amount much LARGER than phosphorus, but is often overlooked.

This post was edited by Strawberryhill on Wed, Aug 6, 14 at 13:37


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RE: What else can I do for my roses?

Strawberryhill, I used alfalfa meal for the tea, added Epsom salt, iron granules, and dyna bloom (liquid fertilizer). Last week I put alfalfa pellets and fish meal down and worked it into the soil. We had rain and yes I just can't get rid of the BS. Last year I sprayed so much that I got less blooms and even more BS. Is the Mill's Magic better against BS than the alfalfa meal?


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RE: What else can I do for my roses?

Thank you, Kentucky Rose. You help me tremendously by your keen observation. I'm grateful for your experience, since it confirms my hunch that the Milorganite (sewage sludge) I test recently, with 4% iron, is causing my roses to break out in B.S. I DID NOT put Milorganite on Frederic Mistral, he broke out in B.S. on bagged cow-manure alone. .

Candida Yeast is a fungi. Check out this excerpt from about yeast infection from Livestrong.com website: "At the same time, iron also improves the virulence of the candida species, which is the ability of the pathogen to invade the host or human cells, according to the authors of the study. Another study in the March 2011 issue of the journal "PLOS Pathogens" also points out that individuals taking iron supplements to treat anemia and related disorders have an increased risk of getting candida infections."

Another excerpt from below link: "To successfully sustain an infection, nearly all bacteria, fungi and protozoa require a continuous supply of host iron." "Mechanisms of microbial iron acquisition are determinants for the kinds of cells, tissues and hosts in which pathogens can flourish."

**** What's wrong with Milorganite I use which cause such break-out of black spots in my roses? Its NPK is 5-2-0, with zero potassium, it's sewage sludge, high in salt. Its 4% iron promotes fungal growth.

Thank you, Kentuckyrose, for your info: "I used alfalfa meal for the tea, added Epsom salt, iron granules, and dyna bloom (liquid fertilizer). Last week I put alfalfa pellets and fish meal down and worked it into the soil ... I just can't get rid of the BS."

Alfalfa meal pH is 5.7, zero salt. Epsom salt (magnesium sulfate) is salty, deficiency is rare except in sandy soil ... my clay is tested exceedingly high in magnesium. Fish meal is salty, high in phosphorus (great B.S. inducer). Iron granules is another fungal promoter. Dyna bloom NPK is 3-12-6, super-high in phosphorus, that would zap out the zinc (a strong anti-fungal nutrient).

Roses break out in B.S. when they are stressed out, be it too much salt, and not enough potassium. In humans, a low-potassium & high salt diet will cause stroke. In plants, a low-potassium & high salt intake is a fungal promoter, like iron.

Mill's Magic is low in potassium, high in Milorganite (salty sewage sludge). Another recipe for black spots. One lady in clay soil & hot climate killed over a dozen of her roses by fertilizing with Mill's Magic monthly.

THANK YOU, Kentucky_rose, you helped me with my garden. I'll quit using Milorganite, and return that bag of red-lava rock (high in potassium, plus high iron). I'll go back to what I did last 3 years with very clean roses by using alfalfa NPK 2-1-2 (decent potassium & calcium), then topped with horse manure (pH 8) and high in potassium & calcium. Below is the base of Golden Celebration, picture taken in late October in its 3rd year. It has layers of horse manure & alfalfa meal ... all my roses were clean for 3 years, until I quit that approach.

Here is a link that might be useful: Iron: Fungal and protozoa infections

This post was edited by Strawberryhill on Thu, Aug 7, 14 at 10:11


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RE: What else can I do for my roses?

Here's Pat Austin with horse manure on top of alfalfa meal ... 100% clean for 3 years. This 4th year I stopped that, it has 2 B.S. leaves at the bottom.


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RE: What else can I do for my roses?

Here's hybrid tea Sweet Promise, notice the shine on the leaves. It no longer has that shine, after I quit using alfalfa meal. Lack of blooming is often a potassium-deficiency. Frederic Mistral was stingy on me for 2 years, until this 3rd year I used sulfate of potash, and got 70 blooms for spring flush. Alkaline tap water, with unstable calcium hydroxide, often binds with potassium (reduced blooming), and binds with phosphorus (dull blooms' color). Once I use sulfate of potash & gypsum to neutralize the UNSTABLE lime in tap water, I get more blooms.

I don't spray my roses whatsoever. All the pictures are taken with just alfalfa meal, and horse manure on top.


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