Thanks for the reminder, Sherry. Too early yet for my roses but I'll keep it in mind for a little later this month when they start to really grow.

Moderation is best, considering aphids and other insects' attraction to high nitrogen. The salt index of ammonium sulfate is 88.3% per University of Illinois table, and 68.% per 20-20-20 NPK formula. It's best to use lesser salt source like blood meal, and zero-salt nitrogen as in coffee ground, alfalfa meal, and other organic sources.

I can see using nitrogen if die-back is severe in harsh winter, but very little nitrogen is needed if it's green to the tip in a warm climate. This spring I'll research on what the Michigan State University Botanist said, "it's the absence of nitrogen that induce blooming, rather than the addition of phosphorus."

Case in point: One year I threw blood meal on marigolds, and got 3-feet tall plants with zero flowers for the entire summer. Later years I used zero fertilizers, and got 6 inches marigolds so loaded with blooms that I can't see leaves.

See the link below for salt index of fertilizers, with nitrogen fertilizer being the highest. If you scroll down to the bottom of the page, you'll see the lowest salt index is NPK of 2-20-20, that of 7.2 as in hydroponic soluble fertilizer .... which I'll test that against another higher nitrogen, and higher salt source. I will report the results late in summer.

Here is a link that might be useful: Calculating salt index in fertilizers

This post was edited by Strawberryhill on Sat, Apr 6, 13 at 21:08

We really RARELY use high-nitrogen fertilizers.

I've found, in our environment, we get better results using horse manure or alfalfa tea, with the growth hormones those contain.

Not sayin' that applies to everyone -- but it's so, here, in Alkaline-Land.

Jeri

I second Jeri, I'm in alkaline clay land. Clay is like a slow-released fertilizer. I NEVER fertilize my deciduous trees, and they are taller than 2-story building, air is composed of 78.09% nitrogen.

Sandy soil requires more nitrogen due to leaching, and zero nutrients in sand. However, nutrients is best applied at balanced NPK, low-dose, and slow-released as in animal manure, so less would be leached due to rain.

Dry climate like CA would require less nitrogen, due to less rain, and less nitrogen leaching. Nitrogen moves with water, while phosphorus and potassium stay put where applied. Excess nitrogen produces top growth at the expense of shallow root, more watering, and more pests.

In my thread "Results of different fertilizers", from 2 experiments the best results were with higher potassium. Potassium is needed to fight disease, and for the overall health of the plant. Phosphorus is needed for flowering and root growth (essential for winter survival and drought-resistant). Nitrogen is least needed once the mass, or the height is attained.

This post was edited by Strawberryhill on Sat, Apr 6, 13 at 22:27

In Florida's sandy soils, N levels quickly drop to virtually non-existent, so it is important to use N here. Of course lots of organic matter in the soil slows the loss, but if the pH is above 5.5 (as it should be for roses), the N will get nitrified into nitrate, which leaches right out of organic matter as well.

Oh, thank you, Malcolm!! May I say I love you? Your confirmation was timed perfectly.

Sherry

Here is a link that might be useful: If only sweat were irrigation...

I checked on the pH for roses: best at 6.5 to 7.

I checked on the pH where nitrogen is most deficient, using the booklet provided by EarthCo. (soil-testing company), also doubled check that with another University Extension.

Nitrogen: plenty at pH 8, but short at pH 5.5. Molybdenum: very low at pH 5.5 and beyond.

Phosphorus: very deficient at pH below 6, and somewhat deficient at pH 8. Correcting low pH by adding lime had been documented to increase yields in crops.

Potassium: plenty at pH 8, but less at pH 5.5 (not as deficient as phosphorus). Calcium: plenty at pH 8, but very low at pH 5.5.

Magnesium: plenty at pH 8, but very low at pH 6 and beyond. My alkaline clay is tested high in magnesium

Boron: can be short at neutral and alkaline. Copper: low at pH 8 and beyond. Iron: very low at pH 8 and beyond. Zinc: somewhat low at pH 8 and beyond.

I also checked on symptoms of excess nitrogen:

eHow wrote on the effect of too much nitrogen: 1) Too leafty ..., this new growth is often weak, soft and sappy, which makes the plant attractive to various pests and unable to sustain the stress of drought. And if the plant is aromatic, it loses much of its fragrance.

2) No fruit or Flowers. It's difficult for fruit and flowers to grow when there is too much nitrogen in the soil. Fruit that does grow is distorted or doesn't ripen properly, while flower buds fall off or are disfigured if they do bloom.

Gardening-Know-How website wrote: "When there is high nitrogen in soil, plants may not produce flowers or fruit. As with nitrogen deficiency in plants, the leaves may turn yellow and drop. Too much nitrogen can result in plant burning, which causes them to shrivel and die."

Nitrogen deficiency isn't bad ... just stunt growth and overall yellowing of the plant. I had a really short rose last summer, with tons of perfect blooms, zero diseases, but pale leaves ... it was next to a tomato plant which stole its nitrogen.

Per the You-tube experiment on soluble fertilizers, the best result was with high potassium plus calcium nitrate. Check out what Wikipedia wrote about calcium deficiency:

"Calcium deficiency may be due to water shortages, which slow the transportation of calcium to the plant, poor uptake of calcium through the stem,[2] or can be caused by excessive usage of potassium or nitrogen fertilizers."

It's always good to check if your soil pH falls in the range where nitrogen is most deficient: when the soil is most acidic, below pH 5.5 ..... at my high soil pH of 7.7, nitrogen is plenty.

Below is the procedure I wrote to get one's soil pH the cheapest way: using red cabbage juice:

Here is a link that might be useful: Cheapest way to test soil pH using red cabbage

This post was edited by Strawberryhill on Sat, Apr 6, 13 at 23:42

Strawberryhill -- you are misinterpreting something. Soil pH does not determine nitrogen content EXCEPT as determining whether or not it will get converted to nitrate by bacteria. Nitrate is highly leachable. pH per se also does not determine the presence or absence of any other element, although it will certainly have an effect on rate of leaching.

I wonder if you're mixing up "availability" with "presence?" I'm not saying it is merely unavailable in our soils; I'm saying it is not present at all.

Nitrogen deficiency can be absolutely deadly, if it is severe enough.

Those of us that have clay soil, acidic or alkaline are lucky. We most likely never need to use the quick release products. But Sherri is in Florida and they basically have sand for soil. You could put a ton of nitrogen in the soil and it will leech away in a week or so. So yes, she does need to dose those roses so they will bloom optimally.

I do question fertilizing the azaleas now. I could be wrong, but I was told that if you give them fertilizer now, it will chase the blooms off. I did that one year, and that's what happened. It could have been a coincidence and again, maybe that doesn't hold true for sandy soils. Most of my azaleas are just starting to bud now, we are so late this year!

Thanks, Buford, but the azaleas here are done. Just a scattered few flowers left and the bushes are mostly leafed out. I did know you aren't supposed to fert until after bloom, but I didn't exactly know why. So thanks for sharing that.

Sherry

Here is a link that might be useful: If only sweat were irrigation...

Azaleas in central Florida are long over. My good old country boy who fertilizes my pastures says that in our sandy "soil" after about 9 inches of rain or irrigation, applied nitrogen is gone and it needs to be refertilized.

BTW, by using compost and soil sulfur I have gotten my pH down to about 6.8 - fine for roses but a little high for azaleas, so I was happy to use the ammonium sulfate. As far as the salt goes, I'm sure if the nitrogen runs through so does the salt. Different strokes for different soils. I think Seil in Michigan says she gardens in sand, too, so it's not just Florida. My garden looks loamy in that it's nice and black from the organics, but it's still sand. I guess that's why we're told to fertilize monthly.

I also remember posting here when I was digging my first rose bed. People were having cows when I listed my amendments: alfalfa pellets AND cottonseed meal AND milorganite AND Rose Tone AND composted manure. My reading said you can't overdo organics because of the timed release aspect of them plus my sand is like a sieve. I never burned anything. I did not use blood meal then. In fact, this is the first time I've ever used it. My problem is that I have never fed monthly, A recent article in the MCRS newsletter calls what I do "binge feeding" and said it was a bad practice, so I'm trying to do better with my feeding consistency. A UF/IFAS report said that alfalfa pellets last 45 days in Florida sand.

Sherry

Here is a link that might be useful: If only sweat were irrigation...

Thanks Malcolm, for your clarification. Yes, I understand leaching in sandy soil, my apology for not including the word "available" in my last paragraph. I grew 20+ roses in pots last summer and I understand how fast nitrogen can leach even in loamy potting soil. Sand is worst.

Few months ago I posted info. from Robert Morris plant foundation, rating the mobility of NPK: "Let's compare the mobility of NPK on a scale of 1 to 10. Nitrogen is a 10 ... extremely mobile and can be lost to leaching. Potassium is a 3. It has limited movement in the soil. Phosphorus has a rating of 1. It is immobile in the soil".

Clay retains ALL nutrients well, but phosphorus is NOT available in alkaline clay due to the its forming complexes with calcium and magnesium in clay soil. In an acidic clay at or below 5.5, nitrogen is much less available, versus abundant at my pH 7.7.

Although University Extensions clearly stated that azaleas and rhodies need very little of nitrogen, the acid-fertilizer Lilly Miller ratio is 10-5-4. I used it last year on my acid-flowering plants, and that was the first time in 12 years that I had to water them during hot summer.

Was it worth it? No, not for my heavy clay where it's already fertile. I just need bring the pH down to the neutral zone for nutrients to be available, rather than dumping salt via fertilizers. The optimal pH of roses as listed by EarthCo. is 6.0 to 7.5, much wider range that what's reported on-line. The optimal pH of azalea is 4.5 to 5.5.

In my last house with slightly acidic clay: 15 years ago the NPK ratio of Bayer Systemic 3 in 1 (insecticide & disease &food) was much higher. I used too much on tiny zone 5a roses. I had the worst infestation of aphids.

In my present house with alkaline heavy clay, pH 7.7:

1) First year of tomato crop, zero fertilizer: bumper crop, had to beg neighbors to take my tomatoes.

2) Third year of tomato crop: used 10-10-10 pellets. Saw fat green caterpillars for the 1st time.

3) Fourth year of tomato crop: kid shook too much 10-10-10 pellets, plants got fried, very little crop.

4) Fifth year of tomato crop: used cow manure. Bumper crop, zero insects nor caterpillars.

5) Most recent tomato crop: last year used chicken-manure pellets, alfalfa meal, and lowered the pH: bumper crop, but plants were too tall. No insects nor caterpillars.

******* The below is a report for roses in alkaline clay ****

1) First year of roses: horse manure (bedding of sawdust) and alfalfa meal. Zero insects, no thrips, no aphids. Roses perfectly clean.

2) Second year of roses: I dumped Acid fertilizer 10-5-4 on tiny William Shakespeare 2000 (own-root). Flowers bud got disfigured. Paul Neyron's bud failed to open. Liv Tyler's bloom got distorted. Scent was gone on Mary Magdalene... had to scrape off the fertilizer. No aphids, some thrips.

3) The ones that I didn't use 10-5-4 fertilizer bloomed best: those with composted leaves, those with horse manure, and those with alfalfa meal. Zero thrips nor aphids on these.

4) I used acid-SOLUBLE fertilizer of 32-10-10 for my potted roses every 2 weeks: had the worst thrips infestation. No idea why chemical nitrogen would attract that much thrips.

Best to add only what's deficient or not available. EarthCo. tested my alkaline clay to be very deficient in phosphorus, and somewhat deficient in potassium. Magnesium is abundant in most soil, except for sandy soil.

I do hope people reading this aren't confused. Hopefully, gardeners know whether they garden in sand or clay. That apparently is the determining factor for nitrogen. Plus there are several factors that make Florida unique. High rainfall exacerbates the leaching problem, I'm sure, but I believe nitrogen even "leaches" into the air from an open bag so maybe we still would have the leaching problem with less rain. Certainly, I'd rather have more rain than we've had this winter and spring -- but spare us from the almost constant raining of last summer for other reasons. Hmmm, a light bulb just went on. I bet that explains the pathetic condition of our roses last summer and into the fall. They were probably starving for nitrogen much sooner than normal.

Sherry

Here is a link that might be useful: If only sweat were irrigation...

Hi Sherry: I agree with you that FOR SANDY SOIL, added nitrogen to organic source like manure is best. Manure has other micronutrients such as iron, magnesium, and calcium which help in chlorophyll production, and nitrogen-availability.

The difference between nitrogen and iron deficiencies?

1) For nitrogen deficiency, the new leaves sprout green, but the older leaves which donated nitrogen, is yellowish.

2) For iron deficiency, mature leaves are green, but the new growth is chlorotic (very pale). I see this problem in my rhododendrons, due to iron NOT available in my high soil pH of 7.7.

The link below explains well the difference.

Here is a link that might be useful: Nitrogen versus iron deficiency.

This post was edited by Strawberryhill on Sun, Apr 7, 13 at 12:40

I don't think nitrogen has any corelation wiih flower thrips - at least not here in Florida. They hit en masse every year at this time when all the oak trees leaf out. They go to town on our roses, and stay throughout the year in small numbers just enough to keep some blooms from being perfect. With or without nitrogen feeding, we have thrips, so I hope no one stops feeding their roses in order to avoid thrips. I suppose if there were no leaves we wouldn't have thrips, but I wouldn't want that situation either. Don't know about thrips conditions elsewhere.

I don't use ferts with such high N-P-K numbers, so I can't comment on your results, but I'm considering supplementing with a soluble fert occasionally (many here do) just to keep up with the leaching, but maybe blood meal at each bloom cycle is the way to go since that's when they seem to take it up most and P & K are so stable. Haven't decided yet so if anyone with sand wants to comment...

Sherry

Here is a link that might be useful: If only sweat were irrigation...

This post was edited by sherryocala on Mon, Apr 8, 13 at 0:05

Sherry, I didn't even think that your azaleas were done already. I made that rookie mistake the first year here. Unfortunately none of the azaleas that came with the house have survived. Not sure if it was just bad planting or they are too close to the house. I was able to save one in a pot and I'm going to try to plant it in a spot away from the house. They were a nice color, so I'd like to replace them somewhere.

One year, I did a mixture of alfalfa, blood and bone meal, cottonseed meal and milorganite. The roses did well and I didn't have to fertilize for the rest of the year. This year we have had a lot of rain, so I'm thinking I may have to fertilize more. But I also use a lot of compost and shredded leaves, so maybe that will even things out. I've never done a ph test. I just assume my soil is acidic because of the always blue hydrangeas.

Hi Sherry: I was planning on putting blood meal in my pots so I checked on it: justaguy2, zone 5, posted this info in the Organic Gardening Forum:

"My advice for adding N is to forget about blood meal as it is usually expensive and it is easy to over apply.

Personally I use soybean meal for my lawn and my gardens. It is roughly 7% N by weight. To fertilize the lawn I spread it at the rate of 10-20lbs per 1,000 sq feet which amounts to a light dusting. This lasts at least a month for high N plants such as turf grass. There is more than N in the soybean meal, of course, but it is the N that I use it for.

Please, when growing in soil (as opposed to containers) don't focus on fertilizers, but instead focus on overall soil fertility. Raise it up with organic matter and only supplement as needed."

Others in that forum reported that blood meal release is very fast. It lasted for the entire season in my heavy clay soil, but less so for loamy potting soil.

The acidic Lilly Miller Ultragreen 10-5-4 has chicken manure pellets and all trace elements (iron, boron, copper, magnesium, calcium, etc..). The package says to apply only once in spring time, it lasted a long time with slow-released chicken-manure pellets.

Here is a link that might be useful: Nitrogen application .... when?

I have nothing to add, Sherry, other than your roses will surely love you even more this year! :)

oh, but, one thing I wondered, cost wise, would fish emulsion do the same as blood meal but less expensive? I don't know, just wondering, Gean

This is fascinating discussion and I'm learning a lot.... I'm wondering how my kitty-litter poop- scoops are doing re: nutrients, nitrogen, etc. I do know the roses are doing very well, better than they have ever done, and so far, no sign of Chili-thrips... anybody out there have an idea abt. that? what kitty-poop provides for the roses? I also have a good layer of leaves and mulch from what the tree-services drop off in the driveway, it seems to disappear rapidly and becomes good dark loam and I dump the kitty-poop under each rose and it becomes part of the whole mess.. .......my 4 kitties do their patriotic duty and keep my little yellow poop-pail filled taking it's journey out to the garden every day....LOL...sally

That's interesting, Sally, thanks for the report .... I wonder the same with horse manure in my alkaline clay: no aphids, no thrips, no black spots nor mildew either. Roses perfectly clean with that stuff.

Strawberry

I used a lot of horse manure as mulch last fall. This spring I do have quite a few aphids (which I just rinse off)

BUT the rest of the garden and neighborhood has them too even with out the horse manure. For me, I think it matters more the location of the rose and when the new flush started. If the rose started early it got aphids and if it is slow to wake up, it missed the first influx of them.

Thank you, Kippy, I always appreciate your info. You are right about location. In my last house, acidic clay I had aphids. 15 years ago, I went bonkers with blood meal and chemical fertilizers, but my husband never fertilizer the lawn, it was always green with very little weeds.

In my present house, alkaline clay I haven't seen any aphids for the past 13 years, and this house is only 1/2 hour away from the last house. We fertilize the lawn in this house (twice a year) Without fertilizer the dandelions and nitrogen-fixation weeds take over... then the neighbors start complaining.

Hi Sherry,

Have you ever tried adding native nitrogen-fixing plants to your rosebeds? I don't know much (like zip!) about Florida natives that fix nitrogen, but I found a few pretty quickly on a Google search--the small partridge pea (annual) and Elliott's milk pea (perennial). Both of these were on the website of the Florida Native Plant Society (link is below). Maybe this wouldn't do a lot, but it might give just a little boost to the soil so your roses could possibly benefit from mini snacks throughout the year.

I use a variety of nitrogen-fixers in my garden. Many are California natives, with some non-natives that like the climate here. I have palo verdes (love this tree so I have 3 Parkinsonia 'Desert Museum'), Lotus scoparius (deerweed), Lotus crassifolius otayensis (Otay lotus), pink fairy duster (Calliandra eriophylla), Santa Catalina Island Mountain Mahogany (Cercocarpis traskiae), lots of California lilac (Ceanothus cyaneus, spinosus, tomentosus, 'Snow Flurry', 'Zanzibar', 'Lemon Ice', 'Diamond Heights', 'All Gold'), as well as non natives like white Bauhinia, various clovers, Austrian winter peas, birdsfoot trefoil, etc.

Guess I'm just a lazy gardener who would rather not have to add stuff to the garden if the plants can do my work for me.;) My plants are lucky to get a little fish emulsion--although a small number get a mild powdered organic fertilizer occasionally. Many plants I feed nothing. Don't know how successful this would be in a much different climate/soil. Here I have mostly sandy loam, with some strips of the garden being clay or sand. Both the soil and water are alkaline and rainfall is low. The only problem being that the city water is high in boron with varying effects on plants.

Melissa

Here is a link that might be useful: Florida Native Plant Society

I had quite a few alfalfa seedlings come up in my horse manure top dressing this year and decided to leave them as they are nitrogen fixers. It will be interesting to see if they make a difference.

Melissa, last year I did just that. I planted Sunn Hemp seeds throughout the garden and was thrilled when most of them sprouted, but when they were about 6" tall, the squirrels chewed them down. I think 3 or 4 survived and grew large. I do think the one next to Gruss an Aachen at the inhospitable curb edge benefited from it because she never looked so healthy and strong. I didn't notice much difference for the roses next to the 3 others. I still have seeds, so maybe I'll plant them. I don't think they will enhance the beauty of the garden though. I'll check into those Florida natives. Maybe they're prettier plants. :))

Floridarosez, I probably have had alfalfa seeds sprout, but I pulled them as weeds. I didn't know what alfalfa looked like. (No snide suggestions, please, to check out the produce section at the grocery store.) If I see anymore sprouts that resemble the pics on Google, I'll let them be. Thanks for the idea.

Sherry

Here is a link that might be useful: If only sweat were irrigation...

I was taking a plant to a neighbor today and we walked around her garden debating where to put it. She noted that the long hedge of clockvine and morning glory is alive with aphids (and baby lady bugs)

Adds to my feeling the roses that got aphids are related to when her hedge got filled too.

Sherry, I left a couple that i thought were alfalfa but when they started blooming yellow I realized they were not and yanked them. But I still have a couple dozen alfalfa plants.

Greenhouse producers of cut roses know how to maximize bloom, and they apply NPK in a 3-1-2 ratio, which is the ratio that roses use. A generous supply of available nitrogen does not reduce flowering in roses--that's an old wives' tale. Repeat-blooming roses bloom better if they have a steady supply.

Of course nitrogen is what burns plants when people overfertilize, but it's easy to avoid that--don't exceed labeled doses of manufactured fertilizer or relatively hot organic sources such as blood meal and poultry manure. Labeled doses are already on the generous side.

I apply small amounts of fast nitrogen every 4-6 weeks.

Thanks, Michaelg.

Sherry

Here is a link that might be useful: If only sweat were irrigation...