Fertilizing containers

EarthBoxes are supposed to be fertilized in a specific manner. Some people on the EB forum choose to do other things; seems most people follow the directions. Reading on Garden Web, there is quite the debate over organic and non-organic fertilizers in containers (not specifically EBs).*

Me? I am interested in finding out what method works best with containers that are either NOT self-watering, or that are self-watering, but don't have a space to put a strip of fertilizer, say in a window box or basket.

Is a diluted liquid, used every watering (say about 1/6 as strong as recommended for every two weeks, which I read recommended on one site), watering directly onto the soil a good method?

Or a foliar spray, such as seaweed/kelp?

Or a side dressing?

Or a vermicompost tea? (I have no compost, though, so that could be hard.)

I haven't found research, but hope I'm just missing it somewhere. Most of the extension sites say something like, "Container plants need a good fertilizer. Use one as directed." Um, yeah, I figured that they needed one.

*Their debate is quite interesting, actually. Many of the members their seem to feel that organic works in the ground, but not in containers. I am using Espoma organic Tomato Tone this year and haven't used it before. It will be interesting to see how the tomatoes do. But, I haven't set a fertilizer strip in my other EBs yet; I was thinking of the Espoma organic veggie fertilizer, but am thinking of using a non-organic one (something I've never done!). One person tried bat guano in one EB and some other guano in another EB. The bat guano, according to him, was much better. Not sure if it was simply better or if some things just do better in containers. If anyone has experience using both organic and regular fertilizers in their EBs, I'd love to hear if you thought one was better than another.

You won't find much information out there on container, especially the sub-irrigated variety. The extensions either don't have the info or refuse to consider container growing worth their time - either way, I've found very little help there.

Here's the deal: In SIPs, you need a fertilizer strip at the top of the container and then you MUST cover the box. If top-down watering occurs, the fertilizer would burn the roots. The strip is used so that the fertilizer will slowly leach into the potting mix over time (as long as the box is kept watered appropriately so that the mix stays moist). I've only used organic fertilizer in my Earthboxes and it works. The common thought process is that you'll need 2 cups of fertilizer for each EB and if it's organic, 3 cups. I've stuck with 2-3 cups or organic and I've had great results. Just try to find a balanced fertilizer with all numbers under 10 - EB's is 7-7-7 but it's not organic (and I'd like to feel good about eating what I grow). Get as close as you can.

I'm not sure where the debate comes in but I would say that there isn't one. The two other SIP growers I work with have been using 100% organic in all of their boxes (buckets, homemade SIPs, EB, etc) with great success.

Now, the "self watering" boxes with no cover - like the kind at Gardener's Supply - are a different story. In these boxes, you would still use a potting mix but treat the mix with a granular fertilizer. I'm working with Commercial Park and they have self-watering crop boxes and this is what the manufacturer has told me. I've not worked with these types of boxes and I'm interested to see how well they wick water from their reservoirs as they don't have covers to trap the moisture in. I'd be willing to be that they dry out much faster and will need to be watered top-down periodically. I'm excited to work with a new medium and if I learn anything new, I'll pass it along.

So:

With SIPs - I would recommend a fertilizer strip (preferably organic), as balanced as possible with all numbers under 10.

With other containers - Treat the mix with a granular fertilizer, per directions. I don't see why you wouldn't use organic here as well.

Good luck.

Tyrus, I've had both containers for several years. I've sometimes covered the EBs, sometimes not. Either way, I've had the exact same results in terms of wicking. So covering doesn't affect that, at least in my experience. When I cover them, I always follow the EB method.

I've been trying different methods of fertilizing (though not in a scientific way) when they are uncovered and I'm not sure what's better. I *should* do some kind of study to compare. I've used kelp as a foliar, I've used some organic something as a liquid. And, I have side dressed using small amounts. I've mixed it in ahead of time.

I keep one Gardener's Supply box as an herb box. It has mint, chives, thyme, savory that all overwinter in it. I rarely remember to do anything to it and it's always fine. But, many herbs are like weeds and prefer spare fertilizer. I have another GS box that I've grown flowers, pepper, tomatoes, beans, etc. in. I have 2 baskets that hang, but have a reservoir, and two window boxes that have a reservoir. I can tell the difference when I forget to fertilize them....but not sure I've noticed a difference as long as they get it in some form.

So, maybe this year I'll compare the two window boxes using two different methods.

FYI - for grins, if you haven't read the gardenweb.com forum related to container gardening, it's quite amusing to see everyone arguing about the organic vs regular fertilizer thing...

I've also used organic fertilizer for 2 years successfully in my SIPS. I found that on my tomatoes last year that the 2-3 cups wasn't quite enough and I had to add an occasional liquid fertilizer to the reservoir. I went with 3.5 cups this year.

D

Wheattoast, what liguid do you like? I'm about to buy something new (I think my old kelp and fish emulsion ones are too old....) and haven't seen a lot of liquids to choose from. I was thinking of ordering some stuff from Garden's Alive (have a 50% off coupon), but they don't have a liquid I want.

There is a longstanding discussion in the Container Forum on the GardenWeb forum site. This thread clearly articulates the differences in soils and fertilizers used in containers.

Many people use self watering containers that are NOT covered. When covered, they are self-fertilizing, self-watering containers and the soil needs different wicking properties. When uncovered, they are usually top watered and either foliar-fed or fertilized through the watering process, leading to a different set of needs.

Another thing this thread does is to provide an interesting take on the nutrient needs of plants. According to this link that is provided in the above link's discussion, most vegetables prefer approximately the same amount of nitrogen as potassium, with a slightly more nitrogen preferred, with very little phosphorus needed. The needs vary over the growth cycle, but an example is romaine which likes about 5-.8-6 during the mid of the growth cycle and beans which prefer 3-.4-2. This chart is a great resource.

I've opted to try a couple of different fertilizers - first, a non-organic water-soluble one that is 3-1-2 that has all minors (Dyna Gro Foliage Pro), along with a silicon/potassium blend that is 0-0-1 (haven't decided; am choosing between two of them). That will give me something close to what most of the veggies seems to want. This one will be supplied in by watering the top once a week using a weak solution.

One a different container (also uncovered with no fertilizer strip), I'll try an organic foliar feed. I am still debating between a few, but am looking at Super Plant Tonic and Grow It Green, from some company in Arkansas as one of the options.

I've decided to try an experiment. I have been emailing a guy in Michigan with an online and brick and mortar store for greenhouse supplies. He also has a large greenhouse business and also grows hydroponically and in containers - both self-watered and not. I've also been reading a lot of the garden web forum about containers. Some of the things I'm trying to take into account include:

-values of NPK in plant tissue show that healthy veggies take much less P than I thought and about the same amount of N and K, even when flowering. I've written down the values of the plants I'm growing and am looking for fertilizers, or ferts, that will provide that. The plants I'm growing use about 3-1-3 to 5-1-5.

-minors are very important in non-organic ferts because they are often not complete. So, any non-organic fert is likely to need a secondary one to make up for what's missing. Minors (meaning things like iron, manganese, molybdenum, etc.) are usually included in most organic ferts, do a secondary isn't as important unless you are mixing them to get the right NPK values.

-silica is very important in container gardening; it's not in the soil and research is showing how important it is.

-the roots that take up nutrients (or nutes as all of the marijuana growing forums call them) are at the top of the soil. The longer roots way down in the soil are primarily taking up water. So, some people are proponents of watering from below and fertilizing from above, using a water drench.

-some ferts, however, like seaweed, are better absorbed through the leaves and should be used at foliar sprays.

-Another theory is that plants do better with frequent small feedings, rather than large weekly or monthly feedings. Some folks are feeding daily with amounts like 1/12th the recommended weekly or bi-weekly amount.

-a lot of ferts are NOT water soluble, meaning you cannot use them in the base of a self-watering container. So, you either have to find one that is soluble or top feed or foliar feed.

-chlorine in the water (all of us in the city and a lot oof us around Chicago have city water which is very high in chlorine) will kill microbes, so you have to either let your water sit in a container for a day or so before you use it or you have to get another watering source.

-a quote from my new greenhouse growing friend, "With the beneficial microbe supplements, in some cases, the extremes that container gardens invariably suffer will limit the healthy establishment of microbial life, which is why with some products they recommend reapplying them regularly. One good example is Foxfarm Big Bloom, which doesn't have a high nutritive content, but is absolutely crawling with microbial life. So, with a weekly re-application of any gentle 'living' supplement, you can achieve a great living root system environment. One good root system inoculate that doesn't need to be applied any more than once or twice is mychorizal fungus. This is available from many manufacturers, and is often included in the best of soil and soiless container mixes, and is particularly useful in a container garden where it will help with moisture retention and giving the plant useful byproducts which help the plant to defend itself from disease and fungus issues."

-another quote, "Plants are, in most cases, able to immediately assimilate salt based nutrients [that means non-organic fertilizers], so these show results more quickly. An easy way to change this, and use organics if you prefer, but get the quicker results of a chemical nutrient is to add an enzyme supplement to the roots with your organic nutrients to help break down them down. We've got several, but our most popular is Earth Juice Catalyst." I found a LOT of forums dedicated to growing marijuana that swore by the EJ Catalyst. Some loved the whole product line, actually.

Here's the experiment:

2 tomato plants will be grown in EBs per EB instructions, using an organic fert (because they are already planted that way!)

Of the remaining containers, I will do the following:

1st will be a non-organic container, watered from the top using Dyna Gro Foliage Pro, a 9-3-6 along with Protekt, a 0-0-3 that contains quite a bit of silica.

2nd is an organic container with a fish and a seaweed mix that totals to a 6-1-5. It will probably be a foliar feed. I also may use Earth Juice Catalyst in this one on a regular basis to keep some microbes alive. Not sure if this is the best place to use the catalyst...maybe I'll use in in the following one.

3rd is a mostly organic container with Pure Blend Pro Grow, a 3-1.5-4 along with Silica Blast, which has neglible NPK, but a goodly amount of silica.

All containers will have mychorrhizal fungi. I used a small amount of the Espoma Biotone Starter with Enzymes (I think that was the name - there are two products similarly names, but I used the one with the mycorrhizal fungi) when I planted my 12 tomato plants outside temporarily. They were 5 inches tall, just hardened, and maybe 5 weeks old. I put the Starter in the soil around the roots and put all plants in one EB. My plan was to let them grow a bit until I received my last Earthbox and was ready to move things around. They were in the soil about two weeks. When I moved them, I was astonished at the roots. They were larger than I've ever seen on a tomato at that age with a ton of them. Not sure if they had fungi attached (I wouldn't now what to look for), but something in that mix made a big difference.

Cool!

I'm interested to see how this works out. You know I can't remember the name of the liquid fertilizer I used. I experimented with 2 kinds which I picked up at Brew and Grow (organic). One was a balanced fertilizer I think something around 8-8-8 and one was balanced more heavily toward flowering. I tried them on 2 different tomato SIPs toward the end of the season and didn't really notice any difference. However, it wasn't really a fair trial - we're only talking part of August and Sept. They both did help turn around my sips as they seem to have petered out with the fertilizer I started them off with. I didn't give it to them every watering but about once a week i mixed up a diluted gallon or so and added it to the reservoir.

here's some info from the University of Wisconsin that may be helpful. The second one says one cup 10-10-10 per bushel (8 gallons of dirt).

http://learningstore.uwex.edu/pdf/A2304.PDF

http://learningstore.uwex.edu/pdf/A3382.pdf

There a LOT of information saying that a 10-10-10 or similar balanced fert is just fine. And, in a way it is. But, is it optimal? When you look at what the plant is absorbing, it's closer to 3-.5-3. That translates into a 6-1-6 or a 12-2-12, just at a different concentration.

I guess, like many things, I like optimal. My career is as an optimizing of organization performance, so seems logical I'd want to optimize by EBs, too, lol.

For anyone who isn't into that and would much rather spend their time doing other things, use a balanced fert. You won't go wrong. If you are, however, interested and into it, feel free to join me and share your results.

It's kinda funny, the people on the MJ growing fora are really, really, really into this. There are endless conversations about getting the most into and out of their plants. There isn't much research into containers in the rest of the world, but these people? If they were not doing it illicitly and were doing it scientifically, they could probably produce volumes!

Holy cow! I ordered the ferts and soil conditioners, amendments, etc. very late on Wednesday, say really about 1 AM on Thursday, from [urlhttp://www.4hydroponics.com/default.asp]this Michigan place [/url].

This afternoonm Friday? They are at my condo!!!!!!!! I ordered about $130 worth of stuff weighing 45 pounds and the shipping was only $16!!!!!!! AND, this guy answers questions in emails, like seriously answers questions. He's my new mail order firm hero. There were very few things that they didn't have that I wanted, too.

I mixed up my first batch of cocktail with my new very cool highly recommended 360 degree precipitator sprayer. What a great sprayer this is - allows you to get both sides of the leaves and it's a very fine mist. Wonderful tool.

Too bad I have pay the bill work to do, otherwise I'd be figuring out concoctions for the remaining plants and containers. Just too much fun!

Well, I figured out this complicated schedule of who gets which ferts when.

This morning, I promptly went out and started with my first container....and screwed it up, lol. I used the fish/kelp combo on my lettuce, when I wanted to use the Pureblend/Silica Blast combo because of the NPK value. No biggie. In a week I can start using the "right" stuff on it.

I wish I'd had this all figured out in the beginning as I would have done it all differently! As it is, it's not nearly as much of an experiment as one would like, because I'm not comparing one fert on tomatoes, say, against a different fert on tomatoes. I'm comparing one on lettuce to one on green beans to one on Asian greens. And, I've many too many variables - top feeding versus bottom feeding, type of fert, etc. Alas, it's the best I can do. I'm looking more to see how well organic does in general, compared to non-organic, so I should be able to tell something. It obviously won't be published, lol.

I was glad that none of the organic ferts were too, too stinky. The fish is a bit odd, but nothing like one I used in the past. Whew! I'm glad to throw that one away.

I have been emailing back and forth with the greenhouse guy some more. A couple of other things he said I thought were worth passing on.

First, most of the fertilizers can't be made more than 24 hours in advance. Not all, but of the ones I'm using, only 1 thing can be made ahead. That makes for a bit more work.

Also, he said that the Silica Blast, a product I'm using to add silica without increasing K, shouldn't be mixed with other fertilizers because it can bind to the other chemicals and render them useless.

He highly recommended using a "tea" made with earthworm castings, humic acid, bat guano, seaweed, etc. This is one of the few things you would let sit a few days to let the microbes multiply. I imagine there are lots of "recipes" out there for tea. I did buy some castings so maybe I'll make some.

Most important was something I'd asked him about, but wasn't prepared for the answer. Chlorine or chloramines. If I understand it correctly, Chicago uses chlorine, but I'm not positive. Either way, these will kill all the microbes that organic is trying to get to grow. In containers, no microbes exist unless you put them there (at least when the mix is soil less, which is usually is). So, you buy products to add mycorrhizal fungi or other beneficial beasties only to have your water kill them!

The rain barrel is the best solution, but not sure I have room for one or can tap into my condo building's downspout without getting into trouble . So, for now, I'm drawing a 2 gallon bucket of water and a 2 gallon watering can and letting them sit. I use these for mixing the ferts and any top watering. I am crossing my fingers and hoping that when I fill the bottoms of my EBs with tap water that the water sits in the bottom of the EB for long enough (it takes about 48 hours) that the chlorine evaporates. I am hoping that not much gets wicked up in the 48 hours. This will work fine now when it's cool and the plants are small....when they tomatoes are huge in August, this won't work.

Last option is to buy a small container that has filters in it. I can fill it up and then draw off filtered water. But, it takes the same space as a rain barrel and has filters to deal with....I'd rather just have the rain barrel. Now, to convince dear hubby and the condo board...

So far my ferts are working well. I hadn't been fertilizing the plants regularly as I was waiting to decide what to try and get them in. Now that I am applying them, I am seeing fast results with both types - the organic and the inorganic. The sun the last few days is helping, too

To each his own, but let me assure anyone who may be just starting out with gardening, this is not rocket science. Water your plants regularly, put them in the sun, fertilize with anything once/twice year and the plants will do just fine. Maybe not optimum, but fine.

Has anybody tried Worm Poop? I like the concept of TerraCycle, and it's readily available at most stores (I've seen it at either Home Depot of Lowe's or both) but I wonder if after being bottled it still has the microbes in it that are the whole point.

Last year, the Ridgeville farmer's market had some guys selling worm castings and tea; haven't checked if they are there now. You can make your own tea from castings (or from any compost or composted manure) by putting a few spoonfuls in water and letting it sit in a sunny place for a couple of days. I found (after I spent money at Gardens Alive or somewhere on nematodes) that one benefit of worm or manure tea is that it's teeming with beneficial nematodes.

teatpuller wrote:To each his own, but let me assure anyone who may be just starting out with gardening, this is not rocket science. Water your plants regularly, put them in the sun, fertilize with anything once/twice year and the plants will do just fine. Maybe not optimum, but fine.

I guess I'd partially disagree. If planting in the ground, as long as you have decent ground, it's not rocket science. Containers, without soil, are a different animal if you want to grow organic, however. It just doesn't work the same with organic fertilizers in a soil less mix; you do have to have a bit of knowledge or you'll end up with poor plant growth at best....or dead plants at worst.

Mhays wrote:Has anybody tried Worm Poop? I like the concept of TerraCycle, and it's readily available at most stores (I've seen it at either Home Depot of Lowe's or both) but I wonder if after being bottled it still has the microbes in it that are the whole point.

Last year, the Ridgeville farmer's market had some guys selling worm castings and tea; haven't checked if they are there now. You can make your own tea from castings (or from any compost or composted manure) by putting a few spoonfuls in water and letting it sit in a sunny place for a couple of days. I found (after I spent money at Gardens Alive or somewhere on nematodes) that one benefit of worm or manure tea is that it's teeming with beneficial nematodes.

While cruising the Web trying to find info about organics in containers, I found many a person who LOVES worm poop. So much so that I bought 5 pounds. I haven't tried them yet, though. My guy in Michigan also highly recommended using them as tea. He said to mix the castings with some other ferts that had humic acid, maybe some guano, and to add a bit of seaweed. He said it's best if it sits for a couple of days to build the amount of microbes. Aeration helps in this...not sure how to do that.

I haven't tried it yet, but he assured me my plants would love it .

ViewsAskew wrote:

teatpuller wrote:To each his own, but let me assure anyone who may be just starting out with gardening, this is not rocket science. Water your plants regularly, put them in the sun, fertilize with anything once/twice year and the plants will do just fine. Maybe not optimum, but fine.

I guess I'd partially disagree. If planting in the ground, as long as you have decent ground, it's not rocket science. Containers, without soil, are a different animal if you want to grow organic, however. It just doesn't work the same with organic fertilizers in a soil less mix; you do have to have a bit of knowledge or you'll end up with poor plant growth at best....or dead plants at worst.

Granted, I assumed containers had potting soil.

I like worm castings - I was wondering specifically about this packaged product by TerraCycle. It sounds like it's basically worm castings tea, but I don't see any evidence that it's packaged in such a way that it will protect the microbial content.

The sales copy on these products (not just this company, but all of the fert companies) is amazingly awful. Or good depending on your perspective, lol.

I certainly can't see anything that says anything about it except it's ready made. But, how long are the microbes alive? I don't know. It says nothing about anything, except that it's 5-1-1, which is awfully high in N. The research I was reading seems to show that plants need 3-.5-3 to 5-.8-6, depending on the plant.

There is also an issue of nutrient needs at different stages of plants growth. Phosphorous is needed for early root growth, so monoammonium phosphate or diammonium phosphate are often used in small quantities as starter fertilizer for corn and wheat even where soil P levels are pretty good.

The most research on nitrogen at various stages has been done on corn because of its importance and because nitrogen fertilizer is a substantial cost. Nitrogen also tends to go back into the atmosphere or leach depending upon specific conditions. Nitrogen loss is an economic problem but can also be a water pollution problem.

Tomatoes with too much nitrogen in early growth stages will have very lush vines but small blossom production and fruit set. Once the first tomatoes of medium to large fruited varieties are about the size of golf balls, nitrogen requirements go up. Miracle Gro for Tomatoes is fine at this stage but should be avoided earlier.

ViewsAskew wrote:The sales copy on these products (not just this company, but all of the fert companies) is amazingly awful. Or good depending on your perspective, lol.

I certainly can't see anything that says anything about it except it's ready made. But, how long are the microbes alive? I don't know. It says nothing about anything, except that it's 5-1-1, which is awfully high in N. The research I was reading seems to show that plants need 3-.5-3 to 5-.8-6, depending on the plant.

Yup, that's what concerns me...