So do you think there is any difference between using these spikes and the method Witherspoon uses to put the food deeper in one area beside the rose?

Feeder roots - the ones that take up nutrients and soil moisture - are located just below the soil surface. There is no need to "bury" any sort of fertilizer product and doing so may circumvent the plant's ability to access it easily, if at all.

All granular fertilizers are recommended to be scattered around the root zone, never buried any more than just scratched into the soil surface. And of course, any liquid ferts are dispersed at the soil surface as well.

I'm not sure I understand the logic of burying a fertilizer or concentrating it in a single location. Why would you want to do that?

I always wondered about this, because I see the spikes on sale sometimes and I have a friend that bought some. Thank you erasmus for posting the question and gardengal for your answer. I don't think the spikes should be too hard to break apart into small pieces, even if my friend doesn't have a grinder. I will let her know.

Using a hammer works really well :-))

Well, the idea of putting food in one location and deeper comes from my friend who worked at Witherspoon. They don't just sell roses, they have a rose garden maintenance service. My friend was part of the rose maintenance crew. He said roses in these gardens were big and beautiful. So I thought maybe deeper fertilizer in one spot must work. I tried plant food spikes in some potted plants including roses last year and had good results. I did a search for these products and at least on Amazon most of the spike products got four and a half stars and many people happy with results. When my friend first mentioned the Witherspoon method of feeding I too wondered why concentrating food in one area would be good. If it didn't work for them, their business would suffer. I do not know whether they still do that or not. My friend worked for them a few years ago.

Also, I know from digging up some roses that many of the roots are deeper than just below the surface.

Another thought....many people put bone meal or other fertilizer in the planting hole. That is quite a bit deeper than surface.

Ask this same question on the Soils forum.....or any of the other plant specific forums (especially Trees and Shrubs). You will get the exact same answer I gave :-)

I didn't say it would not work.......only that it was highly inefficient. And it may very well be that the soils with the Witherspoon situation are adequately fertile so that additional fertilization is not really all that necessary to begin with.

It is also easy to confirm that feeder or hair roots - those responsible for providing nutritional support - are located in the upper soil surface as that's where the nutrients are concentrated as well as soil moisture and oxygen. This is true with even very large plants, like trees. Lower roots are more for stabilization or anchorage but can also be used to access moisture down deeper during times of drought.

You are of course free to apply fertilizers as you see fit and according to whatever recommendations you choose to follow. But as a practicing professional horticulturist, I feel compelled to provide you withe the information necessary to maximize your plants' potential. And you are not going to get that from using fertilizer spikes or burying fertilizer in a specific location :-)

Hello Gardengal,

How deep would you say the majority of the feeder roots on a mature rosebush go? 3 inches? 12 inches? Just curious, it would help me understand surface vs. deeper feeding. Also how far should we fertilize? At the drip line, or beyond?

I totally agree with gardengal. Years ago, I used a lot of those spikes, but later quit because they didn't do much. I put all my fertilizer around the base of the rose (not touching rose itself) out to the drip line, and sometimes scratch it in a little, sometimes not. Diane

The majority of any plant's feeder roots are located within the top 6" of the soil profile. With roses, fertilizing out to the drip line should be sufficient but with larger shrubs and trees, the root system can extend well beyond the drip line. However, unlike roses, most are not heavy "feeders" and seldom require routine fertilization.

I appreciate hearing your first hand experience with these spikes, Diane. Last year the houseplant sized spikes seemed to help the pots I put them in. I am just really curious why Witherspoon concentrated the food in one place like they did. Not sure they still do it. I have written to them. There is no doubt something works for them, but it could be the natural fertility of the soil.

Are you concerned with fertilizing just containers, or roses in the ground, too? Your roses are wonderful, so I wouldn't worry about them. For small pots, I just use good old soluble Miracle Grow mixed in the water they get. I probably use it two or three times a week at half strength, or thereabouts. I'm not very careful, and everything seems to do OK. I have a good potting soil in the containers. Until I get them in the ground, the few roses I have temporarily in 5 gallon nursery pots also get the Miracle Grow treatment. The nursery potting mix is really good stuff, from my favorite local nursery, and the roses seem to love it. Diane

Diane, I'm concerned with food for both. You feed your potted plants a lot more often than I do. Maybe I'll step up feeding. I don't like to use a hose end sprayer for Miracle Grow because my water pressure is not good and I don't feel confident that the proportion of water to food would be good. Seems like I tried a hose end sprayer a long time ago with bad results. For potted plants I use Miracle Grow which I mix up in a huge tub and scoop out with a gallon jug. Have also tried Neptune's Harvest. Also I have tossed 10-10-10 directly on potted plants with good results. I put some horse manure in pots and also top dressed my garden plants with it last year.

Last year I didn't use any Rose Tone due to cost. I did put out 10-10-10 on three or four occasions and had much better rebloom last year, though it was probably partly due to rain.

I'm thinking with these rose spikes that the best time to experiment with them might be on the second fertilizer application. I think I'll go ahead with Holly Tone, maybe some manure, and 10-10-10 in spring. Then later might try some of these spikes on a few of my plants.

To me it's just fun to try things out and see how they do. I know some rosarians will do things that experts advise against like " pushing the zone" for some plants. Some people simply find it worth the effort to see for themselves if they can grow what they supposedly can't grow. I wish them well and it is great to hear from them how their experiment worked. Usually in our community it's " Tell us how it went." Garden experiments are fun as long as they're not disasters. Some are. I value expert advice AND might enjoy doing my own little test. But I might return some of these rose spikes and spend the money on a half price jug of Osmocote. I don't know why Walmart thinks they have to get rid of last year's fertilizer.

I'd like to know what that World Peace rose garden is feeding their plants.

I proudly used the spikes until I read from gardengal that not the best idea. Notice she didn’t say it’s necessarily BAD for plant but it is inefficient. The Nursery products industry, in their effort to cater to our need for convenience, comes up w/stuff that is convenient at the expense of effective.

Yes: consumers buying spikes are paying to have granular fertilizer made into a spike. Meanwhile the plants being fertilized have their roots spread out in a network, and not concentrated in one or two spots - using granular fertilizer in spike form is like trying to feed using liquid solutions sprayed on one or two leaves only.

Speaking of liquid fertilizer sprayed on woody plants in garden or landscape settings as a maintenance procedure...

The Myth of Foliar Feeding - “Fertilizers sprayed on the leaves of trees and shrubs are more effective than soil applications”

https://s3.wp.wsu.edu/uploads/sites/403/2015/03/foliar-feeding.pdf

Also the soil of a given plot should be sampled and sent to a soils lab for analysis before diligent, frequently repeated fertilization programs are undertaken - applying minerals or mineral combinations that aren't needed by a particular site - soils vary from one place to another - can, in addition to being a waste of time and money result in a soil toxicity being produced. Many products sold have significant phosphorus payloads for instance, once too much P is present in a soil that soil has to be dug out and replaced because this mineral leaches very very slowly. And trace elements are so called because these are normally present in the soil in minuscule amounts. Yet many fertilizer preparations sold have combinations of these included.

Note as well that when a method or treatment is tested on a set of plants two sets of the same plants need to be used, with there being a sufficient number of each to eliminate false impressions due to variation. With one of the sets being a control group that isn't subjected to the action or substance being examined - otherwise there is no basis for comparison.

This is such an interesting thread. I’ve always wondered about spikes too and wondered about feeding deeply. Thank you Erasmus for starting this conversation.

I can see burying products, specifically organics (cottonseed meal... etc,) if the intent and design of the product is improving the soil, which in turn can feed the rose, but products more designed to feed the bush, like the spikes and many of the granular rose fertilizers, I would think should be placed (edited to clarify) around the root zone on top or scratched in just beneath the surface....

I do not know why, but I have never thought the spikes could get the "job done" in my nutrient-depleted soil.... it takes a basket full of stuff to get things growing as they should here...

Granular fertilizer just needs to be thrown on top of the root zone. No need to dig around the shrubs and damage small roots just below the surface.

Embothrium, you make good points about how to do a controlled experiment. I don't think I'd have several plants of one variety in the ground to do the comparison with. But I think I could get sort of an idea whether a plant responded well to a fertilizer. Not a precise experiment. I thought about damaging roots also by digging around roots or putting in a spike.

I called Witherspoon Rose Culture and asked about whether they're still advising digging a little hole and putting food in it. They do! They advise it for established plants, not new ones. They think it's easier and that the food doesn't wash away, and gets down to the roots well. They do grow a lot of roses and it must work for them. I think it's worth a try. I don't know if a fertilizer spike would have the same effect or not...seems like it wouldn't dissolve as readily.

I'd like to hear from my friend to see if he used this in his garden. He had big beautiful plants in his old garden. I wrote to my local ag extension agent and he also had doubts about putting food in a small area and about spikes.

It does seem easier to just scatter food around a drip line. A soil test is a good idea..I just never have gotten around to getting one.

Even if you disagree about this feeding method I must say that Witherspoon has excellent bare root plants.

BTW, Prettypetals, what do you feed your plants? You have some beautiful big plants. My nearby rose friend's garden has very different soil than I have. His soil has a lot of clay in it. Mine is sandier and drains a bit too fast. I think a soil that is moisture retentive is one of the best things for roses if it's not too heavy. The late Vernon Rickard of Almost Heaven Roses once told me that water is a rose's best fertilizer.

Like I stated previously, however you choose to fertilize is up to you. But if you understand how plants access and take up nutrients, it becomes immediately apparent that neither fertilizer spikes or 'burying' fertilizer makes much sense botanically.

Think about this: roses are produced commercially either in containers filled with potting soil or in fields. Nobody does anything like digging holes and filling them with fertilizer (or the ever popular planting in individually amended planting hole back-fill) to grow them before they are sold to end consumers. Yet it is believed that these (and numerous other magic practices) are essential to success with these plants on final planting sites.

If a given property has a soil that really seems like it is not up to the task, even with mulching and a normal amount - i.e. conservative and carefully chosen - of fertilization then the places where roses are wanted should be dug out and replaced with purchased soil thought suitable. Or special raised beds made by erecting low walls and dumping purchased soil on top of the existing soil, without blending the two soils together.

I have not seen Witherspoon's gardens in person but do not doubt that they are doing exceptionally well because my friend, who is not a liar, worked in these gardens. I am sure the soil in these various gardens is not uniform. What is consistent is their feeding method. Maybe in theory it should not work but it appears that it does.

Witherspoon told me that they do this with more mature plants, not plants in pots or in fields prior to being harvested for sale. That a plant might benefit from one feeding method while young and another when in the ground does not seem like incontrovertible evidence of a gimmick to me.

Look, I am not pushing this method. I am just curious. I will try it a little. I don't claim to be running a scientific experiment. After growing a certain plant 20 years I think I have a basis of comparison if I try a new feeding method on that plant and see different results.

As far as digging out your rose bed soil if you find you have to fertilize to get optimum results...many of us could not afford that or would not want to do it. Do you think that the Witherspoon method or plant spikes are excessive? I don't. They may use a comparable amount of fertilizer, but not distributed the same way.

Hey Erasmus. I usually do an alfalfa Tea 2-3 Times a year along with triple 10 or sometimes clearanced fertilizers. I don’t have a set routine bc once summer kicks in I get so lazy and am usually dealing with weeds and keeping them watered. I agree with the water comment. I have seen the biggest improvement with blooming with regular watering. The regular watering helps getting the fertilizer watered in good too. I have some clay too which I guess helps it from drying out so bad during the summer. Judy

Thank you, Judy. I kind of guessed you must have some clay in your soil. My yard has areas with different types of soil. I used to get truckloads of leaf compost every spring and some manure but I no longer have a truck. I found a horse stable near me that gives away manure, which we put in plastic bags. I am confused about whether fresh manure is good. I think what I got was somewhat aged but I have heard someone here say that fresh manure is better. ! I can believe that alfalfa tea is better than alfalfa scattered. I scatter it but it crusts over.

Diane must have good soil. What do you feed your plants, Diane? I do think building up soil is better than over fertilizing. Thinking it over, I guess a concentrated dose of fertilizer in a small area would be too much for that area. So might hurt the soil in that spot. Seems like scattered food would be in the soil's best interest if you're going to use chemical. I'm still going to try spikes on a few old plants that are petering out. Whether something works or not is not the same issue as whether it is good for the soil.

I think making a hole and putting in some rose tone might be a good thing to try...seems like it would be less apt to burn or do harm to worms. I have a lot of worms in my soil. I also see rabbit fertilizer here and there.

Rose Tone is an organic fertilizer - it cannot 'burn' plants nor will it adversely affect the soil biology unless it is grossly over applied!! There is no need to bury it and doing so is really counterproductive. In order to be utilized it needs to be where the populations of soil organisms are concentrated and that is just under the soil surface. Also where the concentration of plant feeder roots are located to take advantage of the nutes.

I have not seen Witherspoon's gardens in person but do not doubt that they are doing exceptionally well because my friend, who is not a liar, worked in these gardens. I am sure the soil in these various gardens is not uniform. What is consistent is their feeding method. Maybe in theory it should not work but it appears that it does.

Whenever any method has not been tested using an experiment with controls then it is not known with certainty that it is producing an effect that would not have occurred without its use. This is why human drug trials include giving some participants placebos.

I sprinkled it around sometimes too Erasmus but it is bad to clump. Home Depot had a bunch of smaller bags of granular fertilizers (diff varieties) on clearance about 70-80 % off so I grabbed a bunch. They’re not big bags but a bunch of small ones but that’s ok.

I don't know why Witherspoon first concluded that making holes for fertilizer was a good idea. I don't know if some of their gardens had these and some didn't. They do teach classes in how to feed plants and they teach using this unusual method. Their phone number is online if you want to talk to them about it.

I wrote to the Jobe's plant food spike company also to ask how they test their products. I haven't heard from them.

Does anyone know if fresh horse manure is ok? One rose expert says the fresher the better. I think horse is very different than cow.

Some people advise throwing banana peels on the ground around roses. Seems to me that any benefit would be located in a small area below the peel, kind of like the spikes or holes full of food would be in a small area. Maybe over time with enough peels thrown out there the general area would be improved.

My MIL was a good vegetable gardener and she buried kitchen vegetable waste and rotated the rows the next year. Did not compost the stuff in a pile, just buried it. Deeper soil improvement worked with her vegetables. Hard to believe roses have shallower roots than vegetables. I have seen shallow rose roots snaking out just below the grass, but have also seen plenty of deeper roots that are memorably hard to get out. I don't remember the quantity of feeder roots on them. Could be that they have fewer feeder roots as food and oxygen get less deeper in the soil. I think some deep feeder injection gadgets that use liquid food claim that the plant will produce deeper roots if fed more deeply, and so that plant would be more drought tolerant. Could be just another claim. I know that rosarians are advised to water deeply, not shallowly. If the functioning roots were all on the surface, we'd be advised to water shallowly I think. But if something doesn't work in one garden it is not certain it would not work in another. So it can be tempting and/ or interesting to try something iffy.

There was a great thread a couple of years ago regarding the use of fresh manure. I think the consensus was that it was okay if used as a top dressing.

There were some questions regarding using the manure if something the horse consumed had been chemically treated or maybe if the horse was getting some kind of treatment (do not quite remember that part)... but even then, I think it was an issue if used on or near soil that grew food for human consumption...