it is depend on what do you want to feed them if you want organic just feed them fish emulation or miracle grow every 2 week until sept. after you can still fertilize like 0-10-10 with no nitrogen after until winter come. but if the nursery soil already have fertilize then you don't need to fertilize anymore. if you azaleas is in the container then it need some fertilize if it in the ground you can fertilize less. do not fertilize when it hot do it in the evening at the base it won't pick up nutrient if the weather is too hot. good luck

so you don't agree fertilize with miracle grow (miracid)?

I'll hold off until next year just to be safe. Thanks everyone for the information!

On a complete side note (my first azalea conspiracy theory), I wonder if late fertilizing by nurseries of azaleas sold in the fall has had anything to do with the failure rate of my fall versus spring plantings. Sellers of rebloomers would have more reason to do so, since they may try to force fall blooming. This is just a thought and obviously would just be in addition to all of the other things that could cause fall plantings to fail, like not having enough time to get established before winter.

The main reason for the failure of fall planted azaleas and rhododendrons is that they have too little time to develop an adequate root system before freezing weather sets in. If they are over fertilized late in the season, that would explain lots dead stems the next spring but probably not the death of the entire plant.

whitepinemaple: Miracid provides a quick shot of nutrients which may have some very limited uses in special circumstances. Foliar feeding, for example. As a long term fertilizer, it is pretty much useless. As noted above, azaleas and rhododendrons need a slow, steady supply of essential elements, not a quick fix. In well established plants, mulch should supply all they need unless a soil test indicates otherwise. Newly planted small ones do benefit from small amounts of fertilizer but it should be organic based, slow acting and suitable for acid soil plants.

Actually, when I say failure I just mean a lot of die-back, sometimes to the extent you'd want to replace them. I've only lost a few completely over a winter and those plants were already severely weakened from a prior winter and just never recovered over the interim summer. I'd never think that nurseries overfertilizing fall-sold plants would be the entire reason, just a possible contributing factor. At least under my azalea conspiracy theory. :)

I'll say this one more time...and then hopefully force myself to stop beating dead horses here at gardenweb LOL.

I am absolutely positively, would-stake-my-life-on-it and the lives of those dear to me...that over fertilizing of trees and shrubs (in end-user gardens) is a huge problem, practically one of epidemic proportions. First of all, when you buy 98% of nursery plants, they've already been optimally fertilized _for fast growth_. That's what the wholesaler wants: he wants to get a big, dark green plant out the door as quickly as possibly without killing it with kindness. There's simply no reason at all to fertilize it for at least the first two years. There might be an exception here or there, like bboy pointed out, you could have a plant that sat on a sales yard for 2 years. But in that case, you ideally wouldn't have bought it anyhow because it's going to be rootbound as heck.

You need the plant to spend its first couple years growing a big root system...because it's actively looking for nutrients.

Specifically as for rhododendrons and to a lesser degree azaleas, I'd go even beyond Mainegrower's advice to say mature ones only *need* fertilizer if they are showing some sign of deficiency. Granted he is on relatively open sandy soils (IIRC) and thus knows he would see deficiency if they never got any fert. applications, because e such soils retain so little added nutrients vs. loams or clays. As for a plants *wants* versus its *needs*, I'm convinced there's a very narrow "therapeutic index" with rhodies. Sure you can boost growth and bloom a little bit with a balanced fert. application. BUT if they don't absorb nitrogen very fast, and it's obvious that they don't, any you apply after mid-spring might still be there in the soil come fall. (trapped in microorganisms if you believe it will all wash out) This will tend to keep the plant soft.

I know someone on Long Island who is fertilizing heavily in my opinion. In the recent round of cold winters, he reported damages to me well beyond what I experienced on the same varieties. The minor climatic differences simply cannot account for this in my opinion. Or take as another example a Camellia 'Aida' at Longwood versus one in my own garden. Again, hardly any climate difference on those coldest nights of the last 2 winters. Mine, which I had never fertilized, only had minor leaf edge burning. The one at Longwood, which I'm absolutely 100% sure had been fertilized "correctly" by a horticulturalist with a professional-authority-conveying degree, was killed outright. Not even able to come back from the roots! And it was in a far more sheltered spot! I don't have any 2 acre conservatories on my spread to block the north wind and east sun!

Do you think these up to 100' tall, blooming their heads off R. arboreum in the Himalayas get a yearly application of Miracid or anything like it? No, they get a little animal poop if they're lucky LOL.

https://www.google.com/search?q=laligurans&source=lnms&tbm=isch

I just want to chime in to echo David's sentiments :-) I get asked this constantly (and by my clients, not just here on GW) - when, how often and with what do I fertilize X plant?? And my first response is.....why do you think you need to? Marketing campaigns by big name fertilizer manufacturers have got us - the general gardening public - brainwashed into thinking we can't possibly have a successful garden if we don't fertilize frequently. It simply isn't so! If you are picking the right plant for your climate and soil conditions (and especially if you mulch regularly), you may never need to provide any supplemental fertilizer. Plants should be able to get what they need from the soil and if they can't, they will let you know with slowed growth, poor color or lack of flowering. If and when that happens, then it is time to consider a fertilizer.

Improper or over-fertilization of gardens by homeowners is one of the leading causes of water pollution. Not to mention being a large and often unnecessary expense. In my old, large garden, the only "fertilizer" I ever used was compost, applied as a mulch. Growing harvestable crops like veggies is a bit different, as these plants, when removed from the soil, take nutrients with them and these need to be replaced. And containerized plants need regular fertilization as well, since there are no nutrients to speak of in potting soil and frequent watering leaches out what little may be present. But plants established in the landscape, especially woody plants, seldom require fertilization.

I'm assuming the comments were just general thoughts on fertilizing, but I was asking because these specific plants were yellowing, showing veins, etc. and reacted well when they were fertilized earlier this year. The plants have been in the ground for three years and slowly turned
more and more yellow, possibly as the nursery's fertilizer wore off. The soil has a pH of 6.42 and would like to bring that down as well. All of my other umpteen dozen azaleas are doing great, and I'm not doing anything too them. But the troubled ones are in an area that was filled when they excavated my basement a century ago, so it may be different soil. At least that's my hypothesis.

My only use of fertilizer is for shrubs and annuals and only as needed. I don't cart home trunks loaded with 50lbs bags of fertilizer like my neighbor does for silly things like a lawn. I think if could convince him to do otherwise, I'd immediately petition the Chesapeake Bay Commission to be their Man of the Year.

Yes, the comments were intended generally, not to you personally ;-) And it appears you have been on top of reading your plants' needs and addressing them as required.

I would encourage a soil test at your earliest convenience and to address pH. In the meantime, if chlorosis (yellowing with apparent veining) persists despite earlier fertilization, you could try an iron supplement to green things up. Not a fertilizer - no NPK - but just a mineral supplement to counteract the unavailability of iron in a higher pH soil. Look for a product called 'chelated iron' at your garden center and apply as per directions.

When towsonite says "They came out of winter showing signs of chlorosis, but bounced back really well after being fertilized, so I'd like to give those guys another boost before winter. The soil in our area is slightly acidic, so I'm not sure if the acid was the benefit or if something else was missing, but I'll get it tested someday." I am concerned what fertilizer you use for chlorosis. This is most likely an iron shortage triggered by high pH, high phosphorus, and maybe low iron. WSU has reported Chlorosis is frequently triggered by phosphorus fertilizers. They now only recommend phosphorus if soil tests call for it. I personally have a severe phosphorus deficiency, and still don't have too much of a problem. They blame most chlorosis on high pH and phosphorus toxicity. Sulfur is the best way to address high pH, but it is slow acting, but long lasting. Once the pH is correct, then iron and manganese levels need to be brought into balance. Hence, bouncing back would not be needed each spring. My question is, what are you bouncing them back with each spring?

I had a couple rhodies that had turned a wan color over winter because they weren't fully established. Guess what has happened in the spring? They've turned a dark green again...with nothing added. Just pointing out it doesn't have to be due to a lack of fertilizer.

Rhodyman, this spring was actually the first time I had ever fertilized them. I bought whatever they had at Lowe's at the time, which was "Sta-Green Azaleas Camellias and Rhododendrons Plant Food", and that's what I used this spring. It's labeled as 10-5-4. The iron level on the bag says .1% and .01% water soluble. The azaleas had only been in the ground for three years and were getting more and more yellow as time went on. I recently picked up Holly-Tone 4-3-4 for future years.

The fertilizer is not very helpful unless the pH is correct, in fact it may do more harm than good. My website has a section on correcting pH. Basically you can use a tablespoon of sulfur per square foot each year for a couple years until they look OK the next year. In the meantime, chelated iron will green up everything temporarily.

http://www.rhodyman.net/rhodynho.php#anchorpH

One last question, would the Espoma Soil Acidifier and Espoma Iron Tone be okay to do what you described? Despite the Iron Tone being obviously to provide iron, it is labeled 1-2-3, and according to Amazon it "Provides 5 percent iron and 13 percent sulfur." The Soil Acidifier bag only states, "Sulfur (S)30% (18% Free Sulfur, 12% …….. Combined Sulfur)" I just haven't had luck finding just pure sulfur or "chelated" iron at least on the shelves of the local stores.

Go with the Iron Tone - it will provide the iron the plants need to reduce the chlorosis as well as helping to lower pH. And it is extremely low in N so will not encourage the plant to produce lush stem and leaf growth that may not harden off suitably before winter.

(Note: Miracid/Miracle Gro for Acid Lovers used just once will accomplish the exact same thing. It is dosed with iron and will green up any broadleafed evergreen shrub extremely rapidly, almost like a tonic.)

How did this blatant and misleading ad under Note: become attached to gardengal48's message? Miracid, aka Miracle Gro for Acid Lovers, is a 30-10-10 fertilizer and acidifier. It contains way too much nitrogen for use now and has the potential to make soil too acid with repeated use.

The entire value of sites like Gardenweb will be destroyed if this kind of stealth advertising becomes common. How did it happen?

Ummm, if you take issue with Gardengal's comment...that's fine. But don't accuse the site of being controlled by advertising bots until you are sure it is. The comment seems consistent, overall, with her other comments seen as a whole. A plant with a pale color *might* be iron deficient. If it is, a high iron and nitrogen fertilizer, used once, will ensure a quick green-up. Is it actually a good idea to do that? You seem to think not because that particular formulation is very high in nitrogen.
I'm overall inclined to agree with you, but let's let GG respond. Gardengal, can you confirm you made that statement?
But I agree if they are editing user posts in that way, it would be time to immediately stop posting here.

I agree with aka. The "Note" is totally inconsistent with the message. Also, there are two Miracids, the soluble powder that is useless for field grown plants, and the pelletized version that is much more suitable, but not a suitable as Holytone. WSU has done a fair amount of work that indicates that some chlorosis is caused by too much phosphorus. They are now including phosphorus toxicity as a cause of chlorosis. So adding more fertilizer would make matters worse.

davidrt28: i am surprised you find the Note consistent with gardengal's other comments. I found it so contradictory to her first comment in this thread, not to mention the first paragraph of the one containing the note, as well as completely inconsistent in style and tone that I could not imagine that she had actually written it. If she did write it, my apologies to the site. I will be extremely surprised, however, if she did write it and have no idea where we go from here if this sort of thing was tacked on to a legitimate post.

Gosh, who knew one little addendum would create such a kerfuffle??

Yes, I wrote the "Note" - it is not some sinister advertising bot sneaking into this website.

And I stand by my suggestion as well. A one time use of MG as a foliar spray does exactly what I described and does not create (or never has, to my knowledge and experience) any sort of push of rapid growth that does not have time to harden off properly. Yes, I realize the MG is a fertilizer and a high N one at that, however I am not suggesting its use in the normal, fertilizing way - no routine use, not even watered in as a soil drench.......just a one time foliar spray. The plant will green up virtually overnight. An old time nurseryman offered this suggestion to me many years ago and it works remarkably well and quickly. And has a similar effect on virtually any broadleaved evergreen shrub.

Before you denounce it completely, try it. It generates some rather amazing results.

I'm glad we could clear that up!
Clearly this whole question of fertilization is one that brings out strong opinions in people.
I'm particularly interested in Rhodyman's comment about WSU research the danger of added phosphorus. As uncommon as huge amts. of added nitrogen are in nature...some natural nitrogen is added to soil. Animal wastes, which are much higher in N than P, and nitrogen compounds naturally occurring in rainwater due to lightning. OTOH there aren't many natural processes that add a large amt. of P, and in fact P compounds tend to wash out of the soil. It makes sense to me that too high P would render various cations the plant needs unavailable.

i guess akamainegrower does not like MG (Miracid) or some reason or bad experience with it maybe. i use it once a year to get the soil acidity for my azalea and i use dyno gro foilage pro the rest but at the end of Aug. i use 0-10-10. winter just water when needed. but maybe i am a beginner who don't know anything about azalea. just as long as mine is healthy and green and bloom every year that all it matter. Trying to help someone and get grill for it then i am sorry.

Soils west of the Cascades here in the PNW are acidic but not overly so - typically a pH in the 6.0 to 6.5 range. Iron unavailability is frequent under these pH conditions and often needs to be supplemented either via routine fertilization with acidifying fertilizers, applications of chelated iron or........the one-time per season MG application.

As to the work WSU might have done on this topic with regards to phosphorus, I am unable to find any evidence of it. The best I could glean were discussions about excess P creating issues with Z or Cu uptake - nothing about chlorosis.

I am also in favor of fall fertilization of trees and shrubs should they require it, as it is the optimally most efficient time frame but I wasn't about to introduce that can of worms into this discussion!! I recall posing that concept on this forum a few years ago and was met with some very strong opinions :-)

My apologies to both Houzz and gardengal48 for questioning the origin of the now infamous Note. I do think that gardengal has, should she ever tire of horticulture, a career in advertising awaiting.

As for my having some sort of personal animosity toward Miracid or a bad experience with the product, neither is true. In fact, its use as as a one time foliar feed such as gardengal advocates is the exact exception for using it that I cited myself. I will repeat: Miracle Gro/ Miracid is an expensive and unsuitable fertilizer for rhododendrons and azaleas. It produces a quick shot of nutrients and does nothing to feed in the manner appropriate for ericaecious plants. Relying on it to maintain soil acidity rather than dealing with the soil itself is, imho, bound to cause eventual trouble even though plants give the illusion of health. Relying on various formulations of chemicals rather than healthy soil and sound practices of such things as soil testing and mulching to grow anything is more akin to hydroponics than to gardening.