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kitty_m_gw

Using coconut coir as starting medium - which organic fertilizer?

kitty_m
12 years ago

It's been a long time since I started anything from seed, but this past year, I built a front yard veggie garden (formal topiary style!) So this year I want to start my veggies from seed. I found an old (still wrapped, ie still clean) brick of coconut shavings and I'd like to use it for the starting medium. However, I read online that once the seedlings have their first set of true leaves, fertilizer needs to be added to help them grow since the coconut has none. What I can't seem to find is what kind of organic fertilizer to add. Any ideas?

Comments (17)

  • digdirt2
    12 years ago
    last modified: 9 years ago

    Any liquid fertilizer, as long as it is well-balanced with nutrients, will work fine IF you dilute it to at least half strength. No stronger. Common recommendation is feeding with 1/4-1/2 strength fert no more than 1x a week.

    The issue with using strictly organics for new seedlings is that many of them are single nutrient products - primarily nitrogen - and they lack P and K and mircro-nutrients. So you'll have to shop around to find to find a nutrient blend or make your own blend.

    Also keep in mind that organic fertilizers work best if there is an active soil herd of bacteria to convert them to usable forms for the plants. That is seldom the case with young seedlings since they are started in sterilized products such as your coir.

    Nutrient-blend organics include some of the products from Earth Juice. Bio-Link, and Fox Farm just to name a few brands.

    Hope this helps.

    Dave

  • greenthumb_5
    12 years ago
    last modified: 9 years ago

    I wouldn't even want to use coconut shavings since they hold too much water that seeds start to mold up or the sprouts rotting at the base.

  • capoman
    12 years ago
    last modified: 9 years ago

    Coco is essentially a soilless medium and is more suited to non organic ferts. I would use regular ferts and then switch to organic methods once you plant in the ground which is where organic methods are most suited.

  • solid7
    9 years ago
    last modified: 9 years ago

    Oh, and by the way, coir works fine for seed starting, also. Depending on what type of seeds, I may add a bit of horticultural (very fine) vermiculite. But it's really not necessary...

    Adding liquid seaweed at 1/4 recommended dose has always been a very good recipe for me when starting seeds in coir.

    This post was edited by solid7 on Fri, Nov 14, 14 at 19:41

  • morz8 - Washington Coast
    9 years ago
    last modified: 9 years ago

    You might find this study from Utah State edu interesting....

    Here is a link that might be useful: Coir vs Peat

  • tapla (mid-Michigan, USDA z5b-6a)
    9 years ago
    last modified: 9 years ago

    I wrote this several years ago about coir and CHC's. Both have inherent issues that need to be dealt with when used as a significant fraction of a medium.

    Sphagnum peat and coir have nearly identical water retention curves. They both retain about 90-95% of their volume in water at saturation and release it over approximately the same curve until they both lock water up so tightly it's unavailable for plant uptake at about 30-33% saturation. Coir actually has less loft than sphagnum peat, and therefore, less aeration. Because of this propensity, coir should be used in mixes at lower %s than peat. Because of the tendency to compact, in the greenhouse industry, coir is primarily used in containers in sub-irrigation (bottom-watering) situations. Many sources produce coir that is high in soluble salts, so this can also be an issue.

    Using coir as the primary component of container media virtually eliminates lime or dolomitic lime as a possible Ca source because of coir's high pH (6+). Gypsum should be used as a Ca source, which eliminates coir's low S content. All coir products are very high in K, very low in Ca, and have a potentially high Mn content, which can interfere with the uptake of Fe. Several studies have also shown that the significant presence of phenolic allelochemicals in fresh coir can be very problematic for a high % of plants, causing poor growth and reduced yields.

    I haven't tested coir thoroughly, but I have done some testing of CHCs (coconut husk chips) with some loose controls in place. After very thoroughly leaching and rinsing the chips, I made a 5:1:1 soil of pine bark:peat:perlite (which I know to be very productive) and a 5:1:1 mix of CHCs:peat:perlite. I planted 6 cuttings of snapdragon and 6 cuttings of Coleus (each from the same plant to help reduce genetic influences) in containers (same size/shape) of the different soils. I added dolomitic lime to the bark soil and gypsum to the CHC soil. After the cuttings struck, I eliminated all but the three strongest in each of the 4 containers. I watered each container with a weak solution of MG 12-4-8 with STEM added at each watering, and watered on an 'as needed basis', not on a schedule. The only difference in the fertilizer regimen was the fact that I included a small amount of MgSO4 (Epsom salts) to provide MG (the dolomitic lime in the bark soil contained the MG, while the gypsum (CaSO4) in the CHC soil did not. This difference was necessary because or the high pH of CHCs and coir.) for the CHC soil.

    The results were startling. In both cases, the cuttings grown in the CHC's exhibited I just find it very difficult for a solid case to be made (besides "It works for me") for the use of coir or CHC's. They're more expensive and more difficult to use effectively. The fact that some believe peat is in short supply (no where near true, btw) is easily offset by the effect of the carbon footprint of coir in its trek to the US from Sri Lanka or other exotic locales.
    That's the view from here. YMMV

    I also tend to stay away from any additives to the medium, organic or otherwise, until the seeds have germinated and about to grow their first true leaves. I then use a soluble synthetic fertilizer because I've found that the incidence of damping off diseases are much higher when I'm trying to feed the micro-herd instead of the plant.

    It's important that seedlings have all the nutrients essential for normal growth in the medium and available at all times. The easiest, most efficient, and most reliable way to achieve that end is with a soluble synthetic fertilizer that incorporates ALL the essential elements in a favorable ratio.

    Best luck.

    Al

  • solid7
    9 years ago
    last modified: 9 years ago

    Thank you for taking the time to post, Al. And I won't initiate an argument, just simply point out that some won't use a synthetic, no matter what. I am one of them. I don't have an idea how or where those types of fertilizers are produced, whereas, organics have been around forever, and therefore tried and true. There are good reasons, recycling not the least (i.e., compost, vermicompost) to incorporate this type of routine, of course.

    Since the mid-2000's, when coir started to gain traction, there have been many gains made in using coco. The salt issue is almost completely gone. (there are plenty of scientfic studies to show the effects of salinity, and even side-by-sides of different brands) I do believe that the best brands are now well-known.

    I am more of the mind to use BOTH peat and coir in a mix, to get the best qualities out of both. Again, I like organic growing, and I'll probably always be the one to tell you that there is a taste difference that is a direct trade-off for lack of yield, produced by my lack of cutting edge know-how. Either way, this isn't so much of an attempt to persuade people to choose organic, as to inform those who already have.

    I have a tomato plant growing right now in a 3 gallon pot, with straight Botannicare coir. The color is a little light, but the leaves are absolutely huge, and the yield is very good. Not as vigorous in growth as my SIP tomatoes in straight peat and perlite, but also a different variety. So take it with a grain of salt. I have only fed the coco with Dr Earth organic ferts, once every two weeks a dose of compost tea, and every other week with fish and seaweed. I water it until it runs out, and then let the excess wick back up over the course of the next day.

  • tapla (mid-Michigan, USDA z5b-6a)
    9 years ago
    last modified: 9 years ago

    I do respect the wish to adhere to a particular ideology, and only wish to impart enough information that container growers can decide where they want to be. Personally, when it comes to tomatoes I can't tell the difference in taste between fruit from plants in the ground with no fertilizer other than compost and plants I grow in containers using a soluble synthetic. I tend to be results oriented and not limited by an ideology, so I go with whatever produces the best results. I tend to rely on my medium for its structure and ability to provide an environment that supports healthy root systems and take as much control over nutrition as I can, and find that the ability to be sure plants are getting what they need when they need it, as well as how much of what elements they're getting can be monkey easy and makes a significant difference.

    I also prefer a well-aerated seed starting mix - much more open than peat or coir-based soils. The mixes I use are so coarse you would have to work pretty hard to have overwatering as a problem. I usually sow the seeds and cover with a little peat or Turface fines and keep the surface wet by spritzing until seeds germinate.

    {{gwi:20508}}

    Good growing! Has anyone wished you Happy Holidays yet?

    Al

  • grubby_AZ Tucson Z9
    9 years ago
    last modified: 9 years ago

    This has gotten a lot off topic. The OP was asking about starting with fertilizer, not growing. A three gallon pot is not about seedling starting. Cuttings are not seedlings. "Loft" is not part of the question. When you guys slam different media, you really are slamming techniques.

    I use 100% sterilized peat to start and have the best sprouting percentages I have ever had, zero damping off, and seedlings that are stout and strong. I do not fertilize seedlings until they go into their first transplant pot-up. Just had to say that so you know where I'm coming from. That's different from saying "your method sucks".

    It's not the medium. It's the medium and the technique together. With the right procedures you can sprout your seeds in ground glass. If the OP wants to determine what kind of organic fertilizer to add, then the answers have already been given. The thing is, most of them could work fine. My only addition would be to suggest splitting your seedlings into two or three batches (seeds are cheap) and trying different suggestions on each batch. You'll probably find one works better than the others, and nobody here can really predict which one.

  • cooperdr_gw
    9 years ago
    last modified: 9 years ago

    I added some bone meal which has very low levels of nutrients but I guess it would be organic. I also added some perlite but it was Miracle Grow brand so I doubt it's organic. Perlite is though unless it's that fake Styrofoam stuff.

  • PRO
    sun forum
    8 years ago

    Use coconut coir and biobizz bio grow fertilizer with seasol its organic works good don't need soil get it on eBay cheap

  • PRO
    sun forum
    8 years ago

    Don't ushe bonemeal its cruel

  • PRO
    sun forum
    8 years ago

    I'm a animal lover would never use it not necessary

  • tapla (mid-Michigan, USDA z5b-6a)
    8 years ago

    FWIW - adherence to an ideology as opposed to what's best for the plant is self-limiting, or at least plant-limiting. I'm not saying self-imposed limitations are right or wrong - only that they are limitations; and, to suggest someone else should adopt your set of limitations (ideology) probably falls into the realm of the political. I don't use bone meal for plants grown under container culture, but that's because it's ineffective due to insolubility, not because it's "cruel". Also, coir has inherent limitations that peat doesn't have. If you editorialize against peat (or another substitute for peat) in favor of coir, you're obligated to explain to others how to deal with coir's inherent limitations. Unless you can do that, asking someone to adopt your beliefs for no reason other than your passion re the topic is asking too much.


    Al

  • maxjohnson
    8 years ago
    last modified: 8 years ago

    My seedlings grow find in coir mix with worm casting and mushroom compost. I only use synthetic fertilizer for hydroponics. I don't see the need to buy synthetic fertilizer just to grow some seedlings.

    It also have to do with how finely grind up the coir is, some are too fine and have too much water retention and cause lack of oxygen, same issue with peat. The texture makes a difference. I can play with the drainage and water retention by mixing in my sandy soil.

    I don't know about you, but it seem the coir is better at water retention for me because it wick up water better than peat and distribute the water more evenly, with peat you have to water very thoroughly not get dry spots, coir don't seem to have that issue. They each have their own advantages, I like the fact that coir is pH neutral, my tomatoes love the peat though. Coir is cheaper for me because I get it at wholesale price from a local distributor.

  • tapla (mid-Michigan, USDA z5b-6a)
    8 years ago

    If you like it, please don't change, but for anyone listening in, I'm not sure how you would build a soil notably more water retentive (WR) than a mix of coir, worm castings, and mushroom compost. Because ALL the particles are very small, the laws of physics dictate an extreme amount of WR in that mix. ..... and you really can't "play with drainage and water retention" by adding sand (unless you're suggesting that adding sandy topsoil increases WR).


    Peat and coir have an almost identical water retention curve, but coir does absorb water much better than peat when they dry down to less than 20% WR. That coir is pH neutral is a problem, not a plus. It's too high for plants in containers (ideal container pH is about a full number lower than the ideal mineral soil (garden) pH, and because of that it precludes the use of dolomitic lime as a Ca/Mg source.

    Al