lawn fertilizers are usually mostly nitrogen. I can't remember the name of the thread or the forum member, but someone here got a personally guided tour of the Portland, Ore. Rose Garden and they were told by the tour guide that the roses there are only fertilized with nitrogen.

Also, I've read newspaper articles on rose planting/fertilizing written by Dick Streeper, a local master rosarian here in San Diego, CA. In his planting guides he always says the time to give a rose phosphorus and potassium is in the bottom of the planting hole. He says that unlike nitrogen, P and K move very slowly through the soil and when you sprinkle them on the soil surface all you're doing is feeding the weeds.

Maybe it's because they grow hybrid teas and floribundas. Those kind of roses flower abundantly here in my country, whereas the David Austin roses are kind of slow to repeat flowering.

It's fertilizer, it makes plants grow. It probably will not do much for the soil, but like Miracle Gro, it does what it says it does.

If the soil has clay content, nitrogen may be the only nutrient needed regularly, but you need a soil test to understand what is needed. I don't like the recommendation of "two handfuls." How much is that and how many square feet is it applied to? The fast nitrogen in lawn fertilizer can burn plants if you use too much.

You can safely apply one TB per square yard of 35% N fertilizer if you haven't applied much other N lately. It is mostly fast-acting N which doesn't last long (4-6 weeks). I use it sometimes.

My sandy soil is chronically nitrogen deficient. I use tons of organics, but in the spring I always have to add a fertilizer high in nitrogen, and I use plain old lawn fertilizer. It's amazing to watch how quickly everything greens up. And, yes, it is very easy to burn things with it so be very careful how you apply it.

In our Bay Area clay soils, sometimes nitrogen is the only nutrient needed. I could not speak for your soils. No doubt they are quite different. Our clays are naturally fertile. This area was once known as the Valley of Heart's Delight, a name I like prefer to Silicon Valley.

Actually alfalfa is approximately NPK 321, so it is mostly nitrogen. Many years (such as this one), it is the only fertilizer I use, other than some sulfur on plants that are unhappy with our high pH. The nitrogen in alfalfa is a slow release nitrogen, which I believe to be better. All this assumes that you are adding organic matter to feed the soil. I know gardeners with our clay soils who only add organic matter, and have healthy ornamental gardens. I don't know how many roses they grow. I suspect their gardens are primarily a mix of natives and Mediterranean plants.

Jerome, I think that it takes awhile for the organics to break down into usable nitrate for the roses, so a dose of fast acting nitrate in the beginning of spring helps jumpstart the growth. Or at least that's the conclusion I've come to, esp important for me up here in the PNW where the soils warm up so slowly.

I'm trying a dose of calcium nitrate at the beginning of the season along with the organics to see if that helps the growth process. It's 15-0-0 which I'm using at half strength. I don't want too many more aphids than I'll already have. Kind of a balancing act between helping growth start faster and not attracting bugs through forcing growth.

Your soils are probably warm so maybe this is of no use to you. But anyway, fwiw.

Nothing that won't work about lawn fertilizer, but yes, watch out for the burn. Basically, if you have a soil test, most soils have plenty of phosphorus and potassium, particularly here in the MidWest, and all they need is nitrogen, so if you're going artificial, Lawn Fertilizer (30-0-1 or something like that) is the most convenient source.

If you're trying to go organic, though, stay away...it's very tough on the soil fauna. I've gone both ways, but I'm back to using manure and alfalfa pellets on the OGR's...I think they grow with better vigor that way and I'm not looking for quick bloom! If I grew more hybrid teas however.....

Here is a link that might be useful: Garden Musings blog

In every instance of fertilization there is a specific need being met with just the right nutrient source or you are wasting time and money. Alfalfa pellets etc. can just as easily be unsuitable for a particular soil as a 30% nitrogen fertilizer.

Any nutrient can be over-applied, with destructive results. Many common products have fairly generous amounts of phosphorus in them, once too much of this is built up in a soil that soil has to be dug out and replaced to get rid of it - phosphorus leaches very slowly.

I use it when a plant really needs a quick boost. Not often, but when one does--it works. Here the soil has plenty of everything except N.

I don't fertilize anyway, just apply mulch and patience, then wait and see what happens. It's an experiment. I think our clay is fertile, too, once it gets enough organic matter added to it. It seems to be about neutral as to ph. My roses look good sometimes, but not as fabulous as I see in some folks' photos; but I know the ground still needs vast amounts of amendment. However, whatever's there is healthy, above the ground and below. Sometimes I think I grow roses merely as an incentive to improve the soil, rather than the other way around.
Melissa

Hoovb, that's interesting about the soil and nitrogen...because you are "just down the road a piece" from me. Melissa, that dovetails with what you are saying. My soil is clay too, and I usually just do compost, manure, alfalfa meal, alfalfa hay...whatever I have time for given the year. The roses here look good (to my eye anyway, and a parent is indulgent) except usually from December to February, just before they're pruned. What's very interesting is to see how much the soil has improved in the beds I started working in '04. A beautiful thing, nature.

I also like clay soil overall, and roses seem to do well in it if I keep amending. Also - I don't have to water as much and that's a good thing. The teas are much less water demanding than some of the modern varieties, and after transplanting a 6 year old Mme. Lombard this December, they put scary deep roots into the clay. Frater Basil and I broke our backs trying to get that plant moved! Sorry I'm blathering. Thanks all for these great replies.

Jerome, you are in good company.

Since we are discussing fertilisers here. Does anyone know if roses love mushroom compost? I see some yellowish mushroom/fungi growing underneath two of my rose bush, and my roses appear to be flowering. Or maybe it's just a coincidence.

Exactly how much lawn fertilizer would be safe to put around an established rose bush? As in cups or tablespoons? I would like to try it on a couple.

Regarding mushroom compost.....my roses have always loved it. At a former home, I had raised beds built 2-3 landscape timbers high. Guess I didnt know any better....but filled them with pure mushroom compost. They thrived! I now use a combination of sand, mushroom compost and bark fines and they love that too. But never had a bit of problem with the musroom compost. When I filled those beds.....I got a flatbed traier of it and brought it home steaming.....it took me awhile to load it into the beds, a month or more, but all the roses did great.

To my tiny little closed mind, the idea of putting lawn fertilizer on the roses is sort of like putting your teenagers on steroids....

Susan

To my tiny little closed mind, the idea of putting lawn fertilizer on the roses is sort of like putting your teenagers on steroids....

Susan

Lawn fertilizer--The crack cocaine of the plant world.
-Using tomorrow's energy today!

Susan, you're right. When I first started putting it out, I worried about my earthworms and what it might do in a mostly organic garden. I broadcast it by hand, scattering it very lightly over the entire bed, and then water it in. So far, none of my earthworms have packed up and left, and I haven't burned anything with it. The change in the color of my plant foliage is immediate and amazing.

If I can ever get my garden to the point it's not nitrogen deficient, then of course I won't use it.

Oh wow, I'm logged in. What a concept. Anyway, I was thinking about this lawn fertilizer earlier today and thinking it would be good for a couple of potted bamboo plants, since bamboo is grass, right? Hmmm....sorry...off topic, but I got so excited when I found out I was actually logged in. If I try to log in I can't; if I don't try to log in sometimes I am....it's a puzzlement....

Susan

I certainly would not make a high nitrogen treatment the mainstay of my fertilizing program (I've been doing organic here for 7 years now)...but I am inclined in our nitrogen poor soil (which otherwise is very good) to do a little something a week or so after pruning. Most of the roses here look fantastic this season, but a few (Strike It Rich for one) are dreadful. Strike It Rich was a champ for 2 years, and this spring it looks horrible, and I mulched etc... I just wonder if I'd given it a little extra treat in January if it would be in better shape now. The way it is looking today, I think the whole season is gonna be a bust for that variety. Brother Cadfael looks anemic too.

Again, it's always what your individual soil needs and what product will meet that need. Does not matter how it is marketed as long as it has the right ingredients.

For more on fertilizer (and amendments)...

Here is a link that might be useful: Horticultural Myths

I'm going to have to try this, even though I'm trying to move in the organic direction as much as possible. My soil is almost devoid of nitrogen; I'm emending it drastically with organic matter,but I just gotta see if this might be of help on a temporary basis...regards, bart

It's like a cup of coffee or a candy bar. One cup or a piece of candy when you really need a quick boost can help. Too much all the time, and you burn out.

That's a great analogy, Hoovb! And I love coffee! :-)

Something else I've wondered about re need for additional nitrogen in organic gardens is that as wood mulch breaks down, it consumes nitrogen.

One year in the south I used fresh ground wood chips as a mulch and didn't add any additional nitrogen. My garden really suffered that year, even though I used my regular amendments of composed horse manure and alfalfa. I learned to add some N after that to compensate for what the mulch consumed. It's made me wonder if a garden that uses wood mulch is going to run low on N constantly because as the mulch decomposes, it consumes N.

The only way I know to counter that is to add another source of N to help keep the garden from being consistently short in N. Do you think that's right?

Gean

Yes, that is the theory harborrose, and it is pretty well documented. However, some soils seem more affected by this than others. I have been reading and experimenting with this for years by now. I see two options, either mulch with well composted organic matter (like having a large pile of shredded bark and off cuts for a couple of years, or a more effective compost bin), or add some source of nitrogen to the mulched areas. A simple organic source nitrogen would be dried chicken pellets, and also arguably the cheapest. There's also blood meal, fish meal and products of certain legumes and seeds, but they are in my mind they are more for the soil closest to the rose?

In a natural system such as the forest floor, you always have a layer of fresh mulch over last year's decayed mulch, with the latter supplying gradually available nitrogen.

Mixing undecayed or partly decayed sawdust, wood chips, or autumn leaves into the soil can cause a severe shortage of N. Putting a mulch on top has less effect, and it would be strongest the first year of mulching. Decayed mulch from previous years does give nitrogen back to the soil, and it might be enough to support adequate growth of shrub roses that are hardy in the climate.

My understanding is similar to what MichaelG says. When a wood-based mulch is first on the ground and starts to decay, it uses nitrogen in that process. However, as the decay continues, that nitrogen is released back into the soil. So long as the mulch stays on the surface and is not mixed into it, the nitrogen-binding effect is confined to the surface of the soil.

It wouldn't hurt to add some nitrogen to the ground before laying the mulch - - I use alfalfa for this purpose - - but theoretically it might be possible to reach a sort of steady state, or something close to it. After all, forests and meadows don't need to be fertilized. They sustain themselves. Now it is different when you grow a crop, because you are continually removing material, whether grains, vegetables, fruits, or flowers, so something needs to be added on a regular basis to keep things stable. I suppose that the need for fertilizer has a lot to do with whether you grow your garden like a crop or like a forest.

Must think about this some more.

Rosefolly

Yes, that's good, RoseFolly. We are "cropping" the rose plant when we prune, cut flowers, or remove petals and leaves for sanitary reasons. For that reason, some fertilizing is usually needed. If you grow HTs in a subzero climate, cut lots of long stems, and prune the plant severely each spring, more fertilizer is needed than for hardy shrub roses.

I like the crop and forest analogy, but aren't we "cropping" by even growing roses at all in a garden environment?

I can see that the adequate N availability would be provided by plants growing, dying and decaying in a meadow or a forest. The trees provide their own N by shedding leaves which decay, which nourish. Ditto grasses in a meadow.

But a rose is by definition a crop, isn't it, unless you're talking about a species rose that thrives in a natural environment, like rugosas on a beach or a woodsii at the edge of a forest? A crop being something planted in an artificially provided for growth zone for the planter's own purposes. In that case, I don't see the roses as being able to provide for their own needs, being such heavy feeders.

But maybe some teas could or as michaelg says, some shrub roses. By that time, though, their roots are like tree roots and the roses have become a forest??

Have to think about that. Goodness, roses are fun! I think I agree with taoseeker, though, just need to spend time, years no doubt, experimenting with mulches and methods of fertilizing to see what works best. I wish I'd started growing roses when I was 2.

By "cropping," Rosefolly and I meant removing plant parts with their accumulated nutrients from the garden system. In some styles of ornamental gardening you remove a lot of stuff, and in other styles, not so much. The need for fertilizer varies accordingly.

I use whatever fertilizer is available. If there is some lawn fertilizer left over, it goes into the beds. Some care is required for such a potent product.

During application with a rotary spreader, some goes into the beds anyway. I'm not that neat.

Of course, this is in addition to the continuous application of ground leaves, pine needles and shredded wood mulch. It seems to work.

Here's an older GW thread on using lawn fert. that has some interesting comments.

Here is a link that might be useful: lawn fert. discussion

I remember that thread, wirosarian.

As I understand it, the sticky point among those who want to use synthetics and those who abhor it is the notion that synthetics kill the soil microbes and earthworms in the soil. That's one of the main points of "Teaming with Microbes." I've also read that Jeff Gillman, the author of one of those books on debunking organic gardening myths has said that one or two light applications of a synthetic will not destroy soil microbes, etc. I think Linda Chalker Scott agrees with him. Or so I read. I don't really know, but have to find out for myself.

So, Michaelg, because I'm trying to understand what you mean - then are you saying that the roses, left to themselves with nothing removed, would be able to support themselves with sufficient N through the natural death and decay of its leaves and canes, and that it's only because of pruning and removal of leaves that it doesn't?

I use 'RoseTone' exclusively as a fertilizer. Is it beneficial to give the roses a boost of lawn fertilizer first thing in the spring to get them going? And would I use the lawn fertilizer in addition to the usual feeding of RT? And how much lawn fertilizer is the recommended dosage?
-terry

harborrose-- Yes, that's how roses grow and bloom in the woods with no fertilizer. Of course it would help to have nutrient-retentive soil. I have a once-blooming rose on a clay bank that goes years between fertilizings.

terryjean--Rose Tone contains some fast nitrogen, I think in the form of urea from poultry manure. I wouldn't use more urea at the same time. If you follow the package directions, you are already feeding very heavily with RT, probably more than is needed. However, some organic fertilizers such as alfalfa don't contain fast N, so N can be scarce in cold soils in springtime.

weeds are my main fertiliser. There are millions of them on my allotment, no matter how zealously I hand weed. Well, a few years ago, I stopped carrying them off to the compost heap and tend to leave them on the soil surface. They dont even look that unsightly if you catch them before they turn into huge gallumphing monsters. Best of all, my awful sandy soil has become considerably richer, more friable with NO attention from me. Growing my plants hard also seems to eliminate the usual rush of greedy aphids. I think I may have even read that this is now a recognised technique called trash-gardening or some such term. Works for me - cheap (well, free, really) and easy.

Campanula, Ruth Stout did something similar.

I quote: "The secret to Ruth Stout's "No Dig/No Work" method is keeping a thick mulch of any vegetable matter that rots on vegetable and flower gardens."