Too much nitro is not good.
You can thin, but wait and see what happens.
Most fruit bearing plants will drop or not set
more than they can handle.
The toms will probably be smaller.
And may ripen quicker.

That does not really answer my question. I don't want to thin, I want increased production of larger fruits that mature. I assume that the best way to make this happen is to have enough foliage on the plant to maximize photosynthesis (if this is not accurate, someone please correct me). I assume that the best way to get more foliage is to use a higher nitrogen (vs. higher phosphorus) fertilizer, if fertilization is necessary (if this is not accurate, someone please correct me). I also am assuming that once the plant has exploded with flowers and once these flowers have set fruit or dropped, I don't have to worry that more phosphorus is required or that additional nitrogen will somehow cause problems with fruit development, rather I assume that once the plant has flowers and the fruit has set that it is photosynthesis that is required to make fruits grow and mature (if this is not accurate, someone please correct me).

Thanks!
Anthony

If it was me I probably wouldn't do anything. You can give a feeding of Tomato Tone or any balanced fertilizer but personally I wouldn't give it a lot of nitrogen. I don't think it will do what you want in the time you have. JMO. JD

Ok, once again that does not really answer my question. Let me try this another way. I will be fertilizing with something, either a MG mix with higher phosphorus or a MG mix with higher nitrogen. If my plants have just put out a bunch of flowers that have largely been pollenated, what plant characteristics will best achieve growth and maturity of this large number of fruits that are concentrated in several bunches in a small range of stem length, and which fertilizer choice will be more likely to help the plants do so, and most importantly please indicate why/on what scientific basis are you answering in the manner that you answer.

Thanks!
Anthony

I have always been told to apply ALL the phosphorus preplant as it is not mobile in the soil. Additional applications of nitrogen and potassium can be sidedressed.

Quote from OK Extension Publication
"Sidedress Nitrogen (N) ApplicationÂIrrigated tomatoes
will need an additional 50 pounds of N per acre when the
first fruits are about the size of a nickel. Higher N side-dress
rates will generally retard maturity but give higher seasonal
yield. Therefore, no more than 50 Ib N/A is suggested when
early maturity is desired. A second 50 Ib N/A sidedress
application will likely be needed one month later especially on
sandy soils in periods of high rainfall.
For extended harvest a third 50 Ib N/A sidedress application
may be needed if adequate fruit remain on the plants and
plant condition is adequate to support fruit development."

Another link that discusses fertilization at length--including the factors that influence nitrogen applications.
(ie rainfall, soil type, etc.)

http://pubs.caes.uga.edu/caespubs/pubcd/B1312.htm#Lime

Another link: Calif extension

http://www.ipm.ucdavis.edu/PMG/r783900711.html

Here is a link that might be useful: Commercial production including fert.

Anthony, This is from "Hydroponic Tomatoes" by Howard Resh Ph.D. Basically they have three nutrient formulations for the different growth phases of tomatoes and as the NPK are in ppm (parts per million) it will give you an idea of the ratios to use in your ferts for soil grown tomatoes.
Seedling to 14"-16" tall;
N-100ppm
P-40ppm
K-200ppm
14"-16" tall untill 24" with fruitset on first cluster;
N-130ppm
P-55ppm
K-300ppm
After first fruit set to plant maturity;
N-180ppm
P-65ppm
K-400ppm
One product that comes pretty close and has the micro nutrients as well and can be used for soil or hydroculture is MaxiGrow by General Hydroponics and has an NPK of 10-5-14 plus micros.

That is some interesting stuff, thanks for the info!
Anthony

Anthony I'm posting this knowing that it doesn't answer your question as you've already told a couple of other folks who tried to help. (smile)

The plants look good and fruits are setting. The energy needed to mature fruits is going to come from photosynthesis.

So if it were me I wouldn't do a darn thing right now.

Tomatoes are not heavy feeders. I fertiize about three weeks after setting out plants and then at the time when most are setting fruits, and then I may do a foliage application later in the summer and that's it.

Your choice entirely as to what you want to do, I'm just sharing with you what I do and what I'm suggesting you might consider doing.

I know you've got your mind made up to add more fertilizer but just for me will you please pray for sunny skies b'c again, photosynthesis is where the energy is made that allows fruit to mature properly, it doesn't come from more fertilizer encouraging more plant growth as I see it.

Carolyn

Anthony:

Glad to here your garden chugging along.
Did you not sustain a bad hail storm early up there, that wiped out your crop?

Tom

Hi Carolyn, my intention is not to apply extra fertilizer, rather just to apply the appropriate fertilizer, but I do acknowledge that many posters here apply FAR more than they need, and I am likely applying more than I need (but hopefully not excessive), especially this year. I have had fairly poor flowering fruiting, plants were initially leggy, they were then badly sunburned (my fault), and then several rows were destroyed by hail. I chose at that time to give them a doze of higher N MG, and I have them another about a week later (I rarely do more than 4 applications per season, i.e. between June 1 and end of August, so 2 applications in 2 weeks was unusual). Plants seemed to respond very well (got huge, though some could have been a little more lush), but not too many fruits, I assumed too much N plus unfavourable weather. So, I did a light application of higher phosphorus MG, and another light dose of same a week later. Very soon after that I had my flower (they are like dandelions) explosion, and again assumed it was both the phosphorus and the more favourable weather. I suppose could consider this the time that plants are getting their main fruit set, and given that it is slightly later in the season than normal I just wanted to give them an edge (and in the past few years I have found that foliage growth slowed as did fruit growth and maturity as I got later in the season). Since I expected to do at least one more fert application, I figured it should be the right one, hence the question. Not trying to create monsters (I think they are too big already!), maybe I will take some measurements today and again in a week and see if they are still growing nicely and then decide. I have to get better at taking pictures consistently...I never have a good history of the garden season. And your answer did quasi-answer my question!! However I don't believe that plants will only put out as many fruits as they can handle, or at least from my experience if I have 2 of the same plant, the one that produces more fruits produces smaller fruits...which is not what I want.

Tom, hail wiped out 3 front rows and damaged row 4, several plants have come back nicely, I will post a pic later tonight if I can. Neigbour replanted several, but his stubby stems are also doing quite nicely now, I will see if I can get a before/after shot of his place also. Good to know that tomato plants are so resilient (as many of you pointed out!).

Thanks for all of the responses, the first few precocious fruits that have matured have been quite good (two indian stripe and two unidentified but delicious red...wish I could figure out what it was, but was just a stray seed in a packet of black krims a few years back...produces early, long, plentiful, late, blemish-free round pink supersweet 3-inch tomatoes that have green shoulders when green and are solid pink when ripe...very delicious).

Carolyn,
I know this is Anthony's topic, but is it too much to fertilize once a week with half strength in a container rotating between a high phosphorous and a seaweed of 16-16-16 with micros?

Carolyn,
I know this is Anthony's topic, but is it too much to fertilize once a week with half strength in a container rotating between a high phosphorous and a seaweed of 16-16-16 with micros?

****

Mike, I'm not an experienced container grower of tomatoes so I think you should ask your question of someone who is. ( smile)

Carolyn

There's plenty of growing season left in Toronto -- we're zone 6a, so if you have fruitset now, I think they'll probably ripen before the season ends regardless of your fertilizer regimen. All the rain and cloudiness in April, May and June has really delayed the season for me.

6' to 8' feet seems awfully tall for Toronto in mid July. My plants are mostly around 4' to 5' but the fruit began setting a month ago. I wonder if the fertilizing led to rampant plant growth at the expense of fruit production? Just a thought.

Mine too. Biggest is 5'.

6' to 8' feet seems awfully tall for Toronto in mid July. My plants are mostly around 4' to 5' but the fruit began setting a month ago. I wonder if the fertilizing led to rampant plant growth at the expense of fruit production? Just a thought.

Black cherry is pushing 10 feet, one or two of my currant tomatoes are definitely in the 8-foot range. Most large varieties are in the 4-7 foot range.

Pretty sure that my fertilizing with N early on (after the sunburn and hail damage) is indeed responsible for rampant plant growth (which pleased me after early damage to plants) and lack of fruits (not so pleasing). Also pretty sure that the increased phosphorus helped with the explosion of flowers (I have one cherokee purple with approx. 80-90 flowers on it right now), very happy about this. After reading the above, if I do feel the need to fertilize again, it will be with a high-N fert to give a bit more of a leg up to the foliage to increase photosynthesis.

Anthony, try a balanced number or the old Miracle-Gro 15-30-15--this will still give you more fruits til the end of the season. You can also try Potassium Nitrate if you just want what you got to get bigger.

Mark

After reading the above, if I do feel the need to fertilize again, it will be with a high-N fert to give a bit more of a leg up to the foliage to increase photosynthesis.

I'm not sure the logic in this. I'd be leery of following commercial practices advice, particularly because the notion of high-N fert + tomatoes goes against the grain of most advice I've read on this issue. Your plants are plenty big and probably have plenty of leaves hence I doubt using lots of Nitrogen will really help. More likely, it'll do what it did before: promote even more plant growth at the expense of future blossoms and more fruit set.

Here's what Dr. Carolyn has to say about fertilizing in "100 Heirloom Tomatoes for the American Garden.":

One of the biggest mistakes tomato growers make is to overfertilize. An overdose of fertilizer will cause too rapid plant growth, which encourages disease, delays blossom formation and fruit set (emphasis mine), and can damage new roots. A good granular fertilizer is one with NPK values of 5-10-5 or 5-10-10.

She goes on to say that she only applies fertilizer twice: two weeks after plant out, and when fruits start setting.

I think that's all pretty good, pretty standard advice.

kdawg I hear ya, but if the existing flowers set like I think they might set, I wont need any more fruit set this year, and my goal will be to grow those fruits as big as I can, as sweet as I can, and try to ensure that they mature before the end of the season (which probably wont be a problem). I have only been doing this for a few years but from all of my experience larger plants with more leaves and more sun exposure produce larger better tasting fruits, and all other things being equal if I had two of the same plant, same size, side by side, the one with fewer toms grew those toms larger than the one with more toms. I used to grow in 2 sections of my garden, one got about 15% less sun, and even during the year that I pruned almost all plants to 1 stem, the ones with less sun produced smaller fruit (and had a bit less foliage) than the same varieties on the sunnier side of the garden...same variety, same number of fruits, same number of stems, same age, same fertilizing, same watering, fruits were smaller.

Even though I have made 4 fert applications in the last 6 weeks, the applications have not been very heavy. Once flowers have set fruit, I will give some pictorial examples, so you guys can see the size of the plants and the number of fruits, should be easier to judge with those additional details. Should know better in a week or so.

My bigger problem might be supporting the plants. I have not pruned this year, and I am staking. Many plants have 5 or 6 bamboo stakes. Lots of potentially large fruit bunches at 4/5/6 feet off the ground, hopefully the stems/stakes are strong enough to hold.

Anyway, are we at least in agreement that once the existing flowers set fruit that lowering phosphorus provided will not affect subsequent development of those fruits, and that if I fertilize with a bit of N and the plants get a bit more foliage, that foliage will help the existing fruits grow and mature (and will also likely inhibit subseqent flowering/fruiting to some degree)?

Commercial people don't want to over-fertilize either. It is costly and can be problematic to plant and environment.

1)Once at planting or preplant application.

2)Once at fruit set. (this is their first side-dressing)

3) Again a month later (ON SANDY SOIL). (This would be equivalent to Carolyn's fish emulsion spray. )

Whether or not another application is made would depend on length of the growing season, soil, petiole tests, weather, etc.

Carolyn, I have a questions about your fert. application 3 weeks later after planting.
You said that your commercial farmer who helped grow your tomatoes tested the soil and ADDED WHAT WAS NEEDED (if anything). I believe this would have been done preplant as is common practice. He also grew cover crops. Then an application 3 weeks later is understandable. Is this correct?

Why do I belabor this point? because people will think all they have to do is plant a tomato plant and fertilize 3 weeks later without realizing their soil is deficient. They may have never grown a cover crop or added any compost. They haven't corrected deficiencies with the help of a soil test as did your commercial farmer grower.
We have discussed this before as you know. :)

Believe me I am not advocating exessive fertilization--as a matter of fact I am a big proponent of compost and organic fertilizers but people have become almost phobic about using any amount of fertilizers. Someone even cautioned about putting grass clippings around a plant--too much nitrogen they said. Grass is not the same as Miracle Gro. :)

The term 'heavy feeder' which you see on most extension literature hasn't helped. According to Peat at NCSU :
"Tomatoes are considered 'heavy feeders' because of their rapid growth and long production season. Production of one ton of tomato fruit removes 3 to 8 pounds N, 0.5 to 3.0 pounds P2O5, and 5 to 12 pounds K2O from the soil."

When we talk about a homeowner sidedressing a plant --I believe we are talking about a tablespoon (or even less) per plant --that's it. Or some sprinkle on additional compost. We are not talking about excessive applications or amounts. Some soils may not need ANYTHING added at all-- everything depends on many individual factors.

Anthony toronto, having tall plants doesn't necessary preclude you will have all vegetative growth and no yield. You just have to find the correct balance--I would love to have tall plants with record breaking yield (ala Charles Wilber's compost grown plants.)

Carolyn, I have a questions about your fert. application 3 weeks later after planting.
You said that your commercial farmer who helped grow your tomatoes tested the soil and ADDED WHAT WAS NEEDED (if anything). I believe this would have been done preplant as is common practice. He also grew cover crops. Then an application 3 weeks later is understandable. Is this correct?

******

No, I didn't say that Charlie tested my soil and nothing was added other than the nutrients from the plowed under winter rye.

Yes, he grew cover crops.

The first fertilization was usually between 2-3 weeks after I set the plants out and the second when fruit set occurred and the third, a foliage feed with seaweed or fish much later in the season if I felt they needed it by looking at them or if there had been lots of rain.

Farkee, Charlie didn't help me grow my tomatoes unless you mean that he prepared my field for me at the same time he prepared his own fields. And yes, I used his seed greenhouse to germinate my seeds and yes, I used a different greenhouse to grow the plants on.

But it was me crawling on hands and knees those long 250 ft rows to set the plants and care for them. When his men had time they'd fertiize mechanically for me but most of the time I had to side dress them by hand. And most of the time I had to hoe or use my Mantis tiller as a mechanical hoe to keep the weeds down.

When I think back of all the houirs I put into growing those tomatoes in that field for so many years I sometimes wonder how I did it all. B'c I had to pick everything myself, save seed for up to 150 or so varieties each season, and on and on.

But these days I'm perfectly happy to grow 25 tomato plants, concentrating on new to all varieties, and Freda does all the work b'c I can't do it anymore b'c of the walker. ( smile)

Carolyn

If you want to take this to the next level see if you can get a copy of this book. "Greenhouse Tomatoes, Lettuce & Cucumbers" by Wittwer & Honma. ISBN 0-870-210-5
Copyright 1979
Michigan State University Press

They went into about everything concerning propagation,fertigation,lighting, C02 enrichment, and how different NPK levels affect flower cluster development, fruitset, tomato production and size. Also goes into the cold treatment of seedlings and how this too can affect flowering and fruitset. Primarily aimed at the commercial grower but has alot of valuable information for the backyard tomato, lettuce and cucumber gardener. Ami

The only reason I disagree with some of Farkee's (& similarly Carolyn's) recommendations is because those are typical recommendations for Ag type growers growing field rows of DETERMINATES, and that is often great for DETERMINATES, plus using organics which take a long time to become available to the plant--sometimes too long...

I feel INDETERMINATES have a more constant need than determinates, since the are continuing to produce every day until killed by frost. (Here's an analogy I use easy to understand: You don't skip feeding your kids certain days or years of their lives, nor give them a 10 lb bag of food when they are 5 & come back & give them 20lbs again when they are 13, why would you want to only feed an Indeterminate tomato plants 2-3x in THEIR lifespan?)

My best method/result with indeterminates is "slow & steady wins the race." I use a fertilizer injector with a hi-P fert early (May-June-July) and a balanced fert with slightly higher K (15-15-18 w/micros, though M-G for Tomatoes works great too) late July thru early September, all at the lowest possible settings.

Anthony, with the CAN$ worth more now you can get a cheap injector for under $50 for next year. Fill it up with a Bloom Booster in May (15-30-15, 10-52-8, etc) and have it on a timer for about 30-40 minutes per day on drip irrigation (1gph emitters) The injector is adjustable (unlike the cheap Hoze-On mixers) and I'd run it once at a regular amount and then set it to trickle mode after that.

Do that thru mid-July & then switch to M-G for Tomatoes (I use Plantex, a Canadian brand, "Soilless 15-15-18 w/micros", that I buy in 25lb bags.) You'll have loads of maters all season long, and big ones too, but indet. plants will be a managable 6-7ft tall. EVERY time you water them they will be fed tiny amounts. Depending on how many plants, if you use the Plantex, the bag will last you 2-5 years or more.

Hope this helps.

MaterMark

"Charlie didn't help me grow my tomatoes unless you mean that he prepared my field for me at the same time he prepared his own fields. "

--that is all I was referring to but soil prepartion is very important no matter who did it. At your other spot you said he prepared the soil biodynamically --that means a whole lot too. In either case you didn't just plant a tomato and fertilize with 5-10-10 without any imputs into the soil prior to planting. I know you know the value of soil prep --I just hope everyone else knows it too.

First of all yes nitrogen gorws foliage. But will it grow fruit no, the foliage which you allready have plenty of, will do that for you. Theres the honest to god science behind it. You have large plants and all they need at this piont is water and sun. Keep it simple, dont overcomplicate something that is this simple, (and supposed to be enjoyable). Depending on the variety of tomato and weather this year in your region, the tomato's are doing just what they naturaly do given the elements of this season. It was a late start for all of us in the north, there fore we're not going to have a verry large harvest in size of fruit, and were all (northern gardeners) experiancing about the same issues. Just be patient and hope for a longer season in the north!

Corey

As far as fertilizing is concerned, (If you are just a small scale gardener and do it for pleasure), I use slow release fertilizer formulated for what ever i feel like growing, I mix it into the first four inches of the top soil, and everything else is done as directed by the product. One application is all you need with this stuff and it will continually feed, no hastle, no guessing games, and it will not overfertilize or under fertilize. I also do my best to keep the ph of the soil between 6 and 7.

Corey

Mark, I see your point. I think alot of people do underfeed and if they post pictures the plants look it.
These plants must produce for many months and need adequate nutrients.
You are using fertigation which is being used more commercially as well--believe me when a farmer has hundred's of thousand of dollars invested they are not doing anything hit or miss.

For most people they don't care about commercial methods anyway--they just want a simple, set in stone method of fertilizing a few plants but there are alot of ways to accomplish this--one just has to find what works best for them and enjoy doing it at the same time. Inground vs container grown complicates the issue too. Plus people have different goals--if it is a hobby and they have lots of different varieties total yield may not mean all that much to them.

--that is all I was referring to but soil prepartion is very important no matter who did it. At your other spot you said he prepared the soil biodynamically --that means a whole lot too. In either case you didn't just plant a tomato and fertilize with 5-10-10 without any imputs into the soil prior to planting. I know you know the value of soil prep --I just hope everyone else knows it too.

****

Farkee, you're a bit mixed up here but again I'm always surprised at how much you remember of what I post. LOL

Charlie is a large commercial farmer and is not a biodynamic soil person. I did what I wanted to in my own field. The only yearly added general nutrients were from the plowed under winter rye that he planted every Fall after initially plowing under the stuff left in my field.

It's Steve Rascher who had the most beautiful garden up here where I now live, which is an hour north from where I did all my large tomato growouts and where Charlie farmed, and it was Steve who used the principles of Rudolf Steiner's Biodynamic soil development.

I could stick my hand up to the elbows in that beautiful soil. Unfortunately Steve had a stroke and can no longer garden so his large garden plot remains vacant b'c his wife wants no part of gardening and is a high energy realtor.

Carolyn

"At your other spot you...." no, I had not forgotten. :)

Carolyn, remember you and I have posted for years and years and the same information comes up time and time again to an army of first time posters. :)

I think I need to post some pics with descriptions of some plant heights/varieties/# of fruits and maybe get some opinions on whether plants appear to be able to properly grow and mature fruits...probably wont be home during daylight until Saturday, will see what I can do then.

If you are using "Mycorrhiza" don't use anything with a phosphorus (P) level higher than 4 or you will render it ineffecteive.

Saw a question about Nitrogen today, thought I would look up this thread and follow up. I did not apply any more fertilizer after my last post on this thread. 2008 was a wacky year and maybe the weather continued to affect things after July 22, but once I stopped the MG, I had virtually ZERO plant growth, nothing got any taller or fuller...have never had plant growth stop this early before. Plants did not get any bigger, and although they had a lot of fruit, the vast majority that were small when I stopped fertilizing (or that emerged soon after) never got close to regular size/to the size of tomatoes that were on the vines prior to this time. Could have been the weather of course, but I assume that a soil test (which I have never done) is in order just to see where I stand. At the very least I think I need to add another 5 yards of triple mix just to fill up the garden (I added another row of 4x4's to the perimeter of the garden so that I could get better soil depth and help drainage).