Weather can have a significant effect on flower colors and scent. I can't think of any even anecdotal examples of soil changing anything until you hit major negatives like chlorosis.

To me, the thing that affects the color of rose the most is temperature and/or sunlight. Colors are deeper in cool spring and fall than in the summer. Then there's the deal where some china roses will darken when exposed to sunlight.

There must be others, but the only flower I can think of that changes color according to soil is the hydrangea which is pink in alkaline soil and blue in acidic.

Fragrance is so mysterious. It can depend on so many factors from humidity to time of day. Some roses don't smell particularly strong up close, but waft and smell strongly from a distance. Others have a strong scent, but it's stays close to the flower so have to get your nose in close to detect it. Most irritating of all is the one that smells amazing one day, and is completely scentless the next.

Long ago in college I was taught that each individual "smells" differently. Certainly we have a different emotional response to scents but this is about picking up the nuances of a fragrance. I once had a rose that I thought had a strong wonderful fragrance but a friend smelling the same rose got no smell or very little. I would love an update on this is someone is knowledgeable on the subject.

I think Jim did this on cut roses. Maybe he'll pipe in. There's a lot on the subject spread throughout many posts on the Organic RF.

Agreed with several posts above -- temperatures and light levels can have big effects; but no known effects of nutrients unless they are truly deficient.

I have alkaline soil, and certain roses do become chlorotic as a result of this--hybrid musks like Ballerina, The Fairy (not a hybrid musk), and occasionally others like Frederic Mistral, for example. I have used various soil acidifying products over the years, and have the chlorosis problem best solved by using a granular fertilizer for acid loving plants. This really does the trick for me. I have also found some differences in blooming, size, and color in certain roses grafted on multiflora compared to Dr Huey as a rootstock. Dr Huey has a slight edge over multiflora here, but the difference is not great. Diane

There are many deficiencies that can affect these...I agree with Vapor that you’ll find lots of really interesting posts on the Organic Rose Growing forum about it. I especially enjoy Straw in Chicago’s experiments and posts, so take a look at those. :-)

Thank you everyone.

Yes I have seen how both color and fragrance are affected by whether...just wondering about nutrients..

Thank you Vap and Perma. I think I will start visiting the organic rose forum. I will look up Jim. And this is the second time someone mentions Straw!

Straws posts are very interesting. I have an engineering background, anand I think it permenatly alters your brain into thinking that you can tweak everything just so to get the results you want. I find her posts fascinating and I do experiment with various things.

Rekha, me too, even though I am not an engineer, I keep wanting to tinker, both to try to get what I want and just to see what happens! Just gottta do it. This Straw sounds like someone I have to get to know!

In Nov 2007 I planted Blush Noisette in a pot. I used ordinary, bought, potting compost. As soon as she started flowering the following spring, she produced the strongest, sweetest, wafting perfume. All through 2008, she had to stay in the pot, whilst I prepared the garden. I used to walk up and down past her, just to enjoy her perfume.
I planted her into the garden early 2009. Same temperatures, same sunlight. She grew and flowered strongly, but there was no perfume,

Ten years later, she is still happily flowering profusely, but has never produced any perfume at all.

Daisy

I can't speak to perfume, but I know the color changes slightly when I add acidic fertilizer to my roses. I have VERY alkaline soil and even more alkaline water. I add a little (tiny amount) of acidic fertilizer and I find the purple and red colors deepen when that is done. The plants really respond to it as well.

What Malcolm said: its all about sunlight and temperature, unless severe nutrient deficiency comes into play.

I want to say, but I dont have too much experience with this, once I started using AA tea the flowers blooming in summer had much, much, more intense color than those in spring. Not deeper. As if the plant was making more pigment in the petals.

Maybe at slightly lower pH, ie mildly acidic conditions, more of the trace minerals are available to the plant?

Thank you for sharing...

Daisy, I am so sorry! Got to find that compost again!

"once I started using AA tea the flowers blooming in summer had much, much, more intense color than those in spring."

I expect this was a direct result of light intensity, day-length, and the subsequent accumulation of resources (sugars) available to the plant. I doubt Alfalfa played a significant role.

There are certainly quite a number of variables when it comes to color and fragrances in roses, and some of them have been mentioned. One of the key elements for color is iron and its bio-availability. I use blood meal for some organic, slow release nitrogen and more importantly, iron. It will really make the colors light up, particularly anything with red in it. Another factor that you might not realize is the rootstock of the plant. Is it on its own roots, or is it grafted onto a rootstock? I would have never suspected it until I was at someone's house who had 4 of the HT Silver Jubilee in his garden, and each was budded onto a different rootstock. While the leaves, stems, thorns, and growth habits of each plant were similar, the flowers were markedly different due to the different rootstocks. It was an eye-opener for me.

..the bustopher... I have found this too... most noticeable on this forum when I see a rose I have, and then see it grown on different rootstocks elsewhere, the growth habit can look quite different... I ignore colour and scent, but sometimes I feel I'm looking at a different rose... I think those on Fortuniana especially seem different to me...

...this is why when I research a rose now on HMF, I have to ignore photos from anywhere other than N. Europe, because we use the same or similar rootstocks.... it's also why I don't post so much here now as I've come to understand that anything I refer to from my own garden, is going to be rather pointless for most members.... I feel it's something other than climate... or not only climate related I should say....

Mal, I agree with BenT. Please continue to post. Your lovely garden is so nurturing for my soul, especially in the summer when everything is fried to a crisp here. It is lovely to see a bit of green. I also would have never know that Dame JD had such ugly and vicious thorns if you had not posted. That is one rose I am going to avoid. Doesn't matter how beautiful the flowers are, ...oh, those thorns!

I agree with what others have said here, Marlorena: keep posting. There are gardeners whose conditions resemble yours, for one thing; and for another, we learn how much gardens and the conditions in which they grow can vary, which is interesting, and at times useful.

...oh thank you so much.... that's so kind.... I suppose when I think about it... everywhere is different... and perhaps none more so than in the States because it's so vast.... so yeah.... you're right... thank you...

Keep on posting, Malorena. Through your posts I can dream that I live in the UK where the Austin roses are much happier.

In regards to whether soil or nutrients affect boom color and/or fragrance, StrawChicago has commented on this numerous times, as others have mentioned above. I wish she would chime in. Check out her comments in HelpMeFind for roses Bolero, Evelyn, and Radio Times. In my own limited experience, Marie Pavie seemed to produce pinker flowers when given steer manure as compared to other years when she was given horse manure or synthetic fertilizers, but it could have been my imagination.

Marlorena, I love your posts! Please keep posting. It is so nice to see the posts from other countries and climate. Your roses are spectacular too!

There are many reasons to peruse the posts here, and researching rose varieties is only one of them. I use the posts for that purpose, but I also use them to learn about composition, color combinations, and management strategies. I also use the posts for inspiration and encouragement. And sometimes just to dream about what it might be like to live and garden in another climate.

Marlorena, your gardens are very inspirational! Even though we are in very different locales, I am very grateful for all I’ve learned from your many beautiful and informative posts. :-)

bustopher: thank you for the tip regarding iron. the only way i have used iron is to add iron chelate when the plant is clearly showing signs of iron deficiency. That works. Other wise whatever iron is there in the soil from regular fertilizers. Do you mean to keep some supplemental iron in the soil say by adding some ironite might lead to richer colors? I cannot use blood meal. So worth trying. One of the first questions I asked after joining this forum is how do the roots of a grafted rose affect the upper part? Most answers were that grafted roses are bigger and give a head start in the garden. Just have to be aware of soil preferences of the root stock. I would have thought something as vital as root tissue can not be just for sucking up food. Roots must have more influence on the top parts. In what way were the flowers of SJ different from root stock to root stock?

Marlorena: I have been on this forum only for a few months. I enjoy your profoundly informed and experienced posts very much. I dont think this forum is only for those who can comment to make matters expedient for US rose growers. Listening to all kinds of input makes it all interesting, worthwhile and a more complete learning experience. Please do keep posting! You see the growth habit being different on different root stock? Thats so interesting too. I just read somewhere that purple roses (such as Ebb Tide) are impossibly puny unless grafted.

noseometer: I have started reading straw's comments. Thank you so much for those leads. My Marie Pavie is decidedly pink. Not at all white. And if it is very hot and the temperature drops a lot like after a strong rain storm the new flowers become deep pink. What is the difference between steer manure and horse manure? (I know those are two different animals and both are herbivores)

I was curious about your manure question and found this.
https://homeguides.sfgate.com/horse-manure-vs-cow-manure-80461.html

katyajini: I also have used in the past a chelated iron product that Ortho used to make called Greenol. I think it had some extra trace elements in it also to help solve the chlorosis problems. For iron, it served the same purpose as the blood meal. It doesn't hurt to have just a little extra iron in the soil. A little is good, but too much more is not necessarily better, and that is true with many things. As far as the Silver Jubilees went, each rootstock will pick up the trace minerals slightly differently to where it shows up in the color of the flowers and the intensity of the shadings, and they were all a little different from each other. Soil pH can come into play with respect to various rootstocks also and their ability to pick up on any of the other trace elements and not just the iron. Again, the iron really affects the reds, and Silver Jubilee is a blended pink. If you really want to see one go nuts on the iron, just try some extra iron on a Chicago Peace. It is like turning on a light bulb the way colors intensify and light up. Maybe someone else out there knows about this one who can also comment.

noseometer: Houzz doesn't like my posting links of references, so I no longer post here but I post in Facebook Fragrant Rose Lovers Group (lots of pics. & links, but few words).

From the below data, the middle number is phosphorus, it's lowest at 0.3 for both horse manure and steer manure. Phosphorus is HIGHEST for rabbit manure at 1.4, chicken manure at 0.8, and cow manure at 0.4. Phosphorus shifts bloom to the red zone, so if you want very deep pink roses, use rabbit manure and chicken manure.

NPK Values of Animal ManuresN Nitrogen %P Phosphorus %K Potassium (Potash) %Cow Manure0.60.40.5Horse Manure0.70.30.6Pig Manure0.80.70.5Chicken Manure1.10.80.5Sheep Manure0.70.30.9Rabbit Manure2.41.40.6

Chicken manure deepens my pinks the most, next is cow manure, then horse manure. If you want DEEPER BLUE, go for more potassium. In Hydrangea growing, potassium shifts bloom to the blue zone, and high phosphorus shifts bloom to the red-zone. I post plenty of pics. in Facebook Fragrant Rose Lovers Group for my bloom-color experiments.

As to iron, it makes leaves deeper green. My heavy clay soil (tested high in iron) DOES NOT AFFECT BLOOM COLOR. The reason why pink roses have deeper color in cold weather is potassium mobility is limited by cold temp., thus more phosphorus released, esp. if you have acidic rain. My blue/purple roses also get deeper color in rainy month since acidic rain also release potassium, IF you DO NOT pile up high-phosphorus manure on such blue/purple roses (phosphorus competes with potassium).

I tested iron sulfate as well as kelp. Kelp deepened bloom colors more than iron sulfate, and kelp was more effective in deep-green leaves as well. Kelp has a wide spectrum of trace minerals. I tested sulfate of potash NPK 0-0-50 (very high in potassium). High-phosphorus CHEMICAL fertilizer turned my Stephen Big Purple into bright red, but WAS NOT effective in producing deeper pink in Sonia Rykiel. But Molasses plus vinegar deepen my pink Sonia Rykiel bloom since that lowered my high soil pH, thus releasing phosphorus & trace elements. (I posted pic. in HMF). Noseometer & other fragrance lovers: You are welcomed to join Facebook Fragrant Rose Lovers group, started by Khalid (he posted in organic rose before). Most of the posters are from Pakistan, very hot climate over 110 F.

Some pics. to show high potassium fertilizer turns bloom deeper blue/purple:

below is twilight zone:

Some pics. to show how HIGH PHOSPHORUS fertilizer, or lowering pH via molasses/vinegar to release phosphorus, can turn blooms deeper pink. Acidic rain does the same in releasing phosphorus:

Below is normal Evelyn with alkaline-tap water in hot & dry & no rain:

Below is Evelyn made more pink by lowering pH via molasses/vinegar:

the_bustopher z6 MO made a good point on IRON, considering that blackstrap molasses which I tested above has: "One serving of molasses contains 1.89 milligrams of iron, which provides more than 20 percent of RDA of iron for men and 11 percent for women". Molasses has CHELATED IRON, readily available to plants. Iron sulfate DID NOT work in deepen pink blooms, since iron sulfate is INORGANIC compound, not chelated.

In the same way, minerals as in CHEMICAL phosphorus DID NOT deepen pink color on my Sonia Rykiel, it bound up and hardened my alkaline clay further. In contrast, BONE MEAL is high in ORGANIC phosphorus, plus many trace elements. I tested throwing bone meal around a dozen geraniums's flowers .. all color ranges deepened and glowed like neon, except the high phosphorus burnt them in summer heat. Bone meal is BEST IN THE PLANTING HOLE.

Others mentioned TRACE ELEMENTS, and I agree. I once put the entire bag of well-composted chicken-manure in the planting hole of Pink Peace (grafted), and it gave me gaudy pink, really hurt my eyes. Way-too-pink compared to another Pink Peace (with horse manure on top (no chicken manure in planting hole). It took a year before the gaudy pink toned down. Chicken manure is high in zinc, copper, and boron, and these trace elements also deepen pink color.

CHEMICAL phosphorus is useless in deepen pink color. Nearby Cantigny rose park used high-phosphorus chemical fertilizer, and their Abraham Darby was beige (almost white). Chicago Botanical Garden's roses turned whitish in spring with lots of rain, They have loamy alkaline soil, thus more leaching of trace elements. Gertrude Jekyll was very light pink, Charles Darwin was almost white instead of yellow. High rain leaches out nutrients .. CBG rose garden had tons of blooms, but all colors are faded with SOLUBLE fertilizer NPK 20-20-20. So trace elements in molasses, kelp, clay, plus phosphorus in manures do help with vibrant colors in flowers.

Even my heavy clay benefit from TRACE ELEMENTS in horse manure. One time I got surplus horse manure, so I threw them on New Guinea Impatients (vast range of colors). All colors glowed from a distance. The neighbor, a Ph.D. in Botany asked me what I did, I told him I used horse manure. The best colors come from HEAVY CLAY and less rain, like the poster Lisa Adams (brownish clay). Ann from Northern CA (Bay area) also posted fabulous colors, same with Seaweed (Costa Mesa, CA) who posted in Organic Rose forum. Both have heavy clay and much less rain.

I have black gumbo clay and high-rain. If we get too much rain (acidic here at pH 4.5), colors of roses got bleached out esp. at Chicago Botanical rose garden (loamy soil). Note that LESS PHOSPHORUS is available at BELOW pH 6, then LESS POTASSIUM with smaller blooms, and LESS calcium & magnesium & sulfur with too much acidic rain. In contrast, Iron, Manganese, Copper and Zinc are less available at pH ABOVE 8, as in hot & dry summer with alkaline tap water at pH 9 (as posted on my village's website). Click on below chart to enlarge:

Hoorah—-now I’m feeling a little fangirlish!!

How fascinating—thank you so much, Straw! :-)

bustopher: thank you! that makes so much sense, that the roots absorb differently, with respect to both the mineral and pH, and that makes so much difference! I will surely pay closer attention as I take care of my garden. My Marchesa Bocella showed significant iron deficiency (yellow veins and puny-ness). After I gave it iron chelate of course the leaves turned a healthy green and the plant started growing much better but the flowers became a very deep pink. If I hadnt known I would think its a different rose.

Straw: Thank you for coming back and commenting on this thread. So many people have said to me, asking the questions I do, I should look up your posts. What can I say, nice to meet you :):):) Flowers gave me the link to the FB group. I dont have a FB account but I will create one and join your group.

You have given so much material to work with. It is a treasure! I have to see how this information works in my hands starting next season.

I have begun to use azomite. Its advertised like a blanket amendment for possibly all required trace elements. However I have not looked up the constituent minerals/elements and there proportions or how it affects soil pH. Do you have an opinion on azomite? I have also started using alfalfa tea which I believe provides many minerals as aa grass concentrates minerals as it grows. Periodically I have used kelp extract too. But I have not systematically tried to up available potassium for instance. I will try that and do a soil test too to know my base line.

And I have been wanting to ask. Many people add dark molasses to their soil..when I first heard that it kind of made up head spin a little. Plants cannot absorb sugars and what about the ants and fruit flies and wasps?? Well I guess its for the iron!

I guess one cannot augment fragrance so readily :(

I use a faked name and faked birthday in Facebook to protect my privacy. Lots of benefits with Facebook Groups: loading pics. is super-fast & easy, versus real pain & extremely-time-consuming to load pics. in Houzz. Folks load like 20+ pics. at once in Facebook in a few minutes, which would take the entire day in Houzz. If my computer wipes out any pics, I can retrieve them if I posted in Facebook, but I CANNOT RETRIEVE THE OLD PICS. THAT I POSTED IN HOUZZ. Houzz does not allow copying any pics. posted in Houzz, EVEN IF THEY ARE MY OWN PICTURES.

In my personal profile in Facebook, I posted pics. and set them to ONLY I CAN SEE, or FOR FRIENDS TO SEE, or to PUBLIC. So my pics. are protected & stored in privacy on Facebook and I can retrieve them later, even if my computer crashed and I forgot to do a backup. With Houzz, whatever pic. you post is Houzz's property, and NOT yours to retrieve later if your computer got wiped out.

It's easy to search for any topics in Facebook, and you don't get Houzz-written-stuff. I quit Houzz since I always post links for reference, and Houzz deleted the ENTIRE THREAD (with other posters' comments), just because there's a link to Amazon to buy THE CORRECT SULFATE OF POTASH. Houzz does not tolerate any commercial link, even if it's beneficial for the public.

I tested Azomite twice, it's mostly calcium plus many trace minerals, but IT'S FAR SUPERIOR TO LIME. There are many trace elements in Azomite that promote FAST growth, and absorption of calcium is best IN CONJUNCTION with other trace elements. Marie Pavie doubled in size, same with other roses (more leaves in late fall).

YES to Kelp. Nothing can give roses deep colors, including dark-green leaves like kelp. The famous rosarian, Kitty Belendez, posted the best pics. of roses in HMF. She has alkaline sandy soil in CA, and uses Kelp in her SOLUBLE fertilizer.

YES to blackstrap Molasses (higher potassium than regular molasses). Dr. Rudolph Ballentine says that, “Since it is a concentrated residue, molasses contains significant quantities of minerals such as iron, a fair amount of calcium and generous quantities of trace elements such as zinc, copper, and chromium.”

NO to alfalfa tea if you have tons of rain. Rain is acidic at pH 5.3 in CA, and even more acidic at 4 in the east coast. pH or rain in my Chicago sub. is 4.5. See the map below of pH of rain across USA. Alfalfa tea is VERY ACIDIC after 3 days. It's useful for VERY ALKALINE region, no rain, but DAMAGE roses for high-rain months. Pickled veggies, or Kimchi, gets sour within a few days (even with salt to slow down the souring). Making alfalfa tea is like pouring diluted vinegar on your roses. I wilted plenty of roses in hot summer when I fixed my pH 9 alkaline tap with vinegar. They also break out in blackspots immediately even in hot & dry weather. Think about how lettuce gets wilted if you pour vinegar-dressing on it. I tested alfalfa tea and roses WERE NOT perky nor healthy.

Houzz makes it impossible to search for any topics, such as "Your top 5 roses", or "blackspots and alfalfa". Houzz's goal is to promote their stuff, rather than help in searching for truth. In the good old days of easy search in Gardenweb, I checked on alfalfa tea, and 2 other people REPORTED black spots on roses when they doused roses with alfalfa tea. Rain is acidic enough, there's no need to make sour alfalfa tea, and the nutrients in alfalfa tea is very low, like 2-1-2. My grass clippings have higher nutrients at 4-1-1. For roses to be healthy, the potassium needs to be at least 10 for disease prevention.

Potassium is LESS AVAILABLE at pH BELOW 6, like alfalfa tea or acidic rain. To prevent diseases prior to rainy month, I top roses with horse manure (pH 8) with lime & potassium & many trace elements, esp. anti-fungal elements of copper, zinc, and boron. Molybdenum is essential for nitrogen uptake and re-growth of leaves, and IS LESS AVAILABLE when pH is below 6. Click on pic. below to enlarge to see pH of rain across USA:

Hi Straw! I love your posts and learn so much from them. I'm trying to follow the Fragrant Rose Lovers group and have not been accepted into the closed group. It appears it has not accepted new members in over a week. I hope we can find a way to follow you. :)

I was wondering where khalid went.

Dotsie and Vaporvac: Khalid, (leader of that group Fragrant Rose Lovers), is building a new house in Pakistan, plus a new job, plus starting a new rose garden. He travels extensively to Europe & other countries. He only checks in his group once a month. If you google "StrawChicago and HMF", you'll find my HMF profile, where I list ALL THE TOPICS that I posted in Organic Rose, such as how to test soil pH ACCURATELY using red-cabbage juice and distilled water (only $1.50). I developed that method with my background in chemistry (B.S. degree in computer science and minor in chemistry).

Houzz converted the links in Gardenweb into different format. Those links that I posted in my HMF-profile no longer work, I would have to re-find the threads that I wrote, then re-post the links in HMF. Houzz is so messed up that I have a hard time finding MY OWN info. which I wrote since 2011 (used to be Gardenweb).

What really helps with gardening is how to test soil pH ACCURATELY. Even the $200 pH meter needs to be re-calibrated each time. I bought plenty of test-kits & pH-meter that didn't work, so I developed my own method (after sending 1 cup of soil to Earth Co. lab to double-check my result). Their report came back to match with my red-cabbage juice test: soil pH 7.7. with rock-hard heavy clay & broke 2 shovels, but I have months of acidic rain at pH 4.5.

Straw, thank you for so much input! You really do take time to inform us. I am reading on with great interest!!

I started writing in Organic Rose forum in 2011, after wasting time & money buying meters & pH-kit-testing that WERE NOT ACCURATE. I bumped up the most important links in Organic rose. About red-cabbage juice, it's VERY USEFUL TO TEST the pH of one's tap-water. After I chop up cabbage, boil it, extract the juice .. I pour the hot juice into soil samples so it dissolve the minerals better. I also boil a tiny bit of my tap-water with a bit of red-cabbage, to compare with cabbage boiled in distilled water. Distilled water is actually slightly acidic at pH 6.8, so it's violet-purple. My tap-water turns deep blue, and my village stated on its website that the pH is 9. I bought litmus-paper for fish-tank and tested my own water, it's also a 9, compared to bottled water at 8.5. Below are the 2 links on how to test one's soil pH using 50 cents of red-cabbage juice and $1 of distilled water. Knowing the pH of one's tap water is useful to know how much acidic agents to add, such as "sour" alfalfa tea, sulfate fertilizers, or SKIP such acidic agents altogether if one's tap water is near neutral.

https://www.houzz.com/discussions/2134007/red-cabbage-ph-test-of-blood-meal-corn-meal-compost-etc

https://www.houzz.com/discussions/2132487/cheapest-way-to-test-soil-ph-using-red-cabbage#n=29