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kevinitis

Mixing my own starter mix- advice needed

kevinitis
12 years ago

Last year, instead of buying pre-made seed starter mix, I figured that I would save money and mix my own for my vegetable garden. Following the ingredients on some widely available seed starting mixes, I started with an approximately 50/50 mix of sphagnum moss (pete) and vermiculite. I added just a little compost to the mix as well. My plants did well at first, but we had a late spring and as time drew on my plant's health declined. So there were problems with my starter mix. I did not add lime last year, so I may have had a ph imbalance. Alternatively the compost may have caused problems, but I don't know for sure. I would like to mix my own this year but I am reluctant to use the same mix. I do have lime this year and I could incorporate some for ph balance but I don't know how much and I am open for suggestions on a totally different mix this time around. I have a new awareness about issues with pete moss and sustainability. What has worked well for you? Any suggested mixes and why?

Comments (20)

  • digdirt2
    12 years ago

    You asked about a "starter" mix and then talk about "mix your own for the vegetable garden" and the problems with growing on in the garden. So are you looking for a recipe for starting seeds or one for a growing mix? They are 2 very different things so can you clarify which you are looking for?

    Dave

  • zen_man
    12 years ago

    I use Premier ProMix BX for both starting and growing. I add extra Perlite for better drainage and aeration.

  • digdirt2
    12 years ago

    I use Premier ProMix BX for both starting and growing.

    Agree as long as we are talking about containers. It is great stuff.

    But this question 'seems' to be about growing on in a vegetable garden, maybe raised beds, if I understand it correctly.

    Dave

  • nhardy
    12 years ago

    I wish I could remember my father start seed mix recipe. The parts are fuzzy for me. Like ?1 pt. perlite, ?2 pt. sphagnum peat moss, ?2 pt. vermiculite,???1/2 teaspoon lime & he added one or two drops of dish soap to the water as a wetting agent.

    Maybe I'll start mixing mine again if someone can confirm the recipe. Last year I thought about it, but the plant supply store was out of peat. What your out? I know can you believe it. (Hummerts) They did not even have their seeds at the beginning of the year. I can't believe I used up all the vermiculite. I got it last year from them. 4 cu. ft. went quick.

    I know you are itching to plant your tomato seeds.

  • kevinitis
    Original Author
    12 years ago

    Ok so to clarify, I looking for a seed starting mix that I grow tomatoes in for approximately 6 weeks and then transplant them into my row crop garden. Is 6 weeks too long to grow tomato starts or should I be transplanting them into growing soil before they go into the garden? Correct me if I am wrong, but I assumed that I could grow tomato transplants for 6 weeks in a starting mix without much trouble. What I am interested in is instead of paying to buy a lot of pre-made seed starter mix, that I could instead pay about half as much for individual components and make it myself. So I am looking for a recipie for seed starter mix. I am open to alternatives to starter mixes that do not use pete moss. Thanks

  • zen_man
    12 years ago

    Hi Kevinitis,

    "I am open to alternatives to starter mixes that do not use peat moss."

    Coir (a byproduct of coconut processing) is an alternative to peat moss, but it is more expensive. Some hydroponics growers use rock wool, but that probably wouldn't be suitable for your non-hydroponic setup. Some commercial mixes use processed tree bark and that seems to work rather well because it drains well.

    The problem with your original mix that combined peat moss and vermiculite was that both ingredients are water retainers. The vermiculite does essentially the same thing as the peat moss, namely soak up and retain water. The result was that your mix was too "soggy" and plant roots would tend to drown in it for lack of oxygen. Instead of vermiculite you should have used Perlite, which aerates a mix and makes oxygen available to the roots. You don't want your mix to be over-water-retentive. The compost you added may have done more harm than good by introducing potentially harmful soil borne diseases.

    I don't know of a cost effective way of buying retail amounts of individual ingredients and mixing them together. Just buying ingredients in small quantities puts you at a serious disadvantage as compared with bulk prices. I buy my Premier ProMix BX in the big compressed bales because it is more economical that way. That means I have to tear the compressed mix apart and "fluff" it up with my hands, but I almost enjoy doing that. My Mother used to say that gardeners can't be afraid of getting their hands dirty. This is a picture of a before and after of blending 5 cups of perlite into 5 quarts of ProMix.

    {{gwi:227084}}
    The "before" is on the right. The ProMix comes with some Perlite already in it, but not enough for my preferences. Not too surprisingly, the Perlite lightens the color of the mix noticeably. I don't know if there is an Earl May Garden Center in your area, but I get my Perlite from them in a big bulk bag, which is considerably more economical than buying it in the small bags. By buying my ProMix in the big bulk compressed bale and my Perlite in a big bulk bag, I get a top quality starting and growing mix at a somewhat reasonably economical price. It's still not cheap. But it doesn't stink.

    I wish you luck in finding a half price recipe. But you are at a disadvantage to start with, if you have to buy your individual ingredients at retail prices.

    ZM
    (not associated with any product or vendor mentioned)

  • kevinitis
    Original Author
    12 years ago

    Wow, thank you Zenman. I do agree that I am at a disadvantage buying at retail. I think you might be onto something with the water retention, that could have been the problem. I do pay close attention to avoid over watering. But in the case of too much water retention as a natural characteristic of my mix, it could be the problem. It may also have been, as you have pointed, that the compost may have caused problems. I don't think that was the problem though because in some batches I used compost, in others I did not. Yet all of the seed treys ended up with problems. Which makes me suspect that was not the case, but it certainly is possible to have problems from that. I do live close to a nursery that sells bulk perolite, vermiculite and peat.

    Here is a link that might be useful: Here is a link about promix BX

  • zen_man
    12 years ago

    Thanks for the link to the Pro-Mix BX technical data sheet. ProMix is now available in three different forms, the general purpose version that was described in the data sheet, Pro-Mix BX with Biofungicide, and Pro-Mix BX with Mycorise which is a beneficial fungus that enters into a symbiotic relationship with your plant's roots. I have used it and the "plain" version, but haven't tried the Biofungicide version yet.

    ZM
    (not associated with any product or vendor mentioned or linked)

  • kevinitis
    Original Author
    12 years ago

    So on the one hand, they add fungi and on the other they kill it. So I guess that you chose between an endomycorrhizae which may give an increase in nutrient uptake, or a fungicide that eliminates some plant pathogens.

  • mandolls
    12 years ago

    If all you are starting is tomatoes - many people in the tomato forum skip the starting mix and go right to potting soil. Apparently tomatoes just dont need to be babied quite so much.

  • zen_man
    12 years ago

    Hi Mandolls,

    Premier ProMix BX is a general purpose mix, and can be used for both starting and growing. It makes excellent potting soil for tomatoes, or most any plant for that matter. Last year I started my tomatoes, including my seedless tomatoes, extra early in ProMix, re-potted them in ProMix, and set them in the garden in full bloom and with small green tomatoes on them.

    I am thinking it is about time for me to start my tomatoes again this year. We have been having some crazy weather here the last few months, and I am going to do some research on what I will consider to be a "safe" no-frost date here this year.

    ZM

  • zen_man
    12 years ago

    Hi Kevinitis,

    "So on the one hand, they add fungi and on the other they kill it."

    Sounds that way. I haven't seen the ProMix with Biofungicide in the local stores yet, so I haven't had the opportunity to try it yet. It does make me wonder if mixing the Biofungicide BX with the Mycorise BX would "cancel the two out".

    I have only a small amount of the ProMix Mycorise left and have started using a new bale of the "plain" ProMix. When we purchased the new bale, the guy at the garden center commented that they "had changed the bag". Apparently he didn't know that they had gotten in a shipment of a different ProMix product. I would like to keep a bale of all three versions of ProMix BX on hand, but so far I haven't had the opportunity to do that. It's all available online, but I don't want to pay shipping costs.

    I don't mind using the plain ProMix. I use dilute hydrogen peroxide for germinating my seeds, and the hydrogen peroxide might destroy any fungus-based additives. I did start some seeds in the Mycorise ProMix using hydrogen peroxide to kill any seed-borne problems, and things seemed to work just fine. But I have some doubts that the Mycorise fungi were able to set up a symbiotic relation with the seedling roots in the presence of the hydrogen peroxide. The seedlings seem fine, though.

    I still wonder what would happen if you mixed the ProMix Biofungicide product with the ProMix Mycorise product.

    ZM

  • kevinitis
    Original Author
    12 years ago

    Now this thread is getting interesting. I would think that if you used hydrogen preroxide you would kill the mycorrhizae, which if you did that, you would lose any benefits attained by the promix mycorrhizae type soils. So you might as well just go with the general purpose product. Likewise, if you mixed the biofungicide product with the mycorrhizae product you would probably lose the mycorrhizae component. So in that case you might as well go with only the biofungicide type soil.

    I have a bit of a background in forest ecology and plant physiology so I have had coursework on mycorrhizae. The reason why you would want mycorrhizae is that it is beneficial to plants. Mycorrhizae in plants provides increased nutrient uptake, better water uptake, and can in some cases actually change (for the better) the structure of the roots themselves. However, this has got me wondering what the specificity of species of mycorrhizae are. In other words, are some mycorrhizae specific to certain species of plants, or are there generalist mycorrhizae that can use a wide range of plant species? Likewise are there some plants that benefit more from mycorrhizae than other plants? That�s a topic to research into more for me. Then finally, what other products are there available that could also provide a mycorrhizae?

  • kevinitis
    Original Author
    12 years ago

    Some mycorrhizae is specific whereas others are generalists. Mycorrhizae also helps increase disease resistances in plants as well.

  • zen_man
    12 years ago

    Hi Kevinitis,

    Here is some information on Pro Mix BX Mycorrhizae.

    "...what other products are there available that could also provide a mycorrhizae? "

    According to this Dig It - Fifth Season webpage, there are "are plenty of companies that sell mycorrhizae" and they link to a couple.

    You have raised several interesting specific questions. Apparently there is quite a lot for us to learn about this subject. Last year I transplanted a lot of plants into my garden that were growing in the medium from my bale, which was labeled "Pro-Mix BX / Mycorise(R) Pro". The package said that Mycorise Pro is a beneficial mycorrhizal inoculum (Glomus Intradices). The label goes on to say that "these microscopic fungi attach to and colonize root systems working in symbiosis with plants. Endomycorrhiza fungi benefit the host plant by increasing acquisition of water and nutrients (especially Phosphorus, Copper and Zinc) by forming an extensive mycorrhizal root system. In exchange, the plant provides soluble sugars to the fungus. This symbiotic relationship between fungi and plant results in overall improved plant growth. Pro-Mix BX is compatible with a wide variety of ornamental plant species, fruit crops and most vegetable transplants."

    I start my seedlings in 3.25-inch square pots, and it is likely that the hydrogen peroxide does neutralize any fungi in them. But I re-pot the developing seedlings to 5-inch square pots, and it is probable that the hydrogen peroxide has dissipated by then and the Mycorrhizae are free to develop normally in the 5-inch pots.

    It is probable that the mere act of setting my potted plants into the ground inoculated the soil at each transplant site. Garden soil is supposed to contain these fungi anyway, but if for some reason there isn't enough, then adding some can be helpful.

    I am not an organic gardener, but I do make compost piles and try to build up the organic matter in my soil.

    ZM
    (not associated with any product or vendor mentioned or linked)

  • kevinitis
    Original Author
    12 years ago

    Zen, Being the scientist I am, I went on google scholar to find out what I could about the use of Glomus Intradices in tomatoes. I found a publication that you might be interested in. All I could obtain was the abstract. The peer reviewed scientific study was published in the journal Biological Control, vol 5, issue 3. The title of the publication is "Biological Control of Fusarium Crown and Root Rot of Tomato in Florida Using Trichoderma harzianum and Glomus intraradices." I could not get the full text version, but I can post the abstract: "Field experiments were conducted to evaluate commercial formulations of two beneficial fungi, Trichoderma harzianum and Glomus intraradices, for the control of Fusarium crown and root rot of tomato, caused by Fusarium oxysporum f. sp. radicis-lycopersici. Tomato seeds cv. "Sunny" were planted into soil nonamended or amended with the biocontrol agents, the former treatment serving as the control. After 6-7 weeks, plants were transplanted into beds fumigated with methyl bromide-chloropicrin in commercial tomato fields with a previous history of Fusarium crown and root rot. Disease incidence and severity were recorded at harvest maturity. Large and extra-large fruits (greater than or equal to 6.27 cm) also were harvested, counted, and weighed at maturity. Total marketable fruit yield was also determined. Compared to the controls, significant decreases in disease incidence were obtained with treatments of T. harzianum (1993), G. intraradices (1991), and T. harzianum + G. intraradices (both years). Significant decreases in disease severity were obtained with the treatments of T. harzianum (1993), G. intraradices (1991), and T. harzianum + G. intraradices (1993). Yields of large and extra-large fruit or total marketable yield were not significantly different over the controls. These data suggest that commercial biological control agents may be effective in reducing Fusarium crown and root rot and that further evaluation of these agents is justified." From that I take it that if fusarium wilt is a concern for you in tomatoes, that you could find significant resistance by using this Glomus Intradices laced product. Makes me go mmmm.

  • zen_man
    12 years ago

    Hi Kevinitis,

    Thanks for the abstract. I wonder where they got their Trichoderma harzianum and Glomus intraradices. I didn't have any trouble with tomato diseases last year, but I will save back a little of my Pro-Mix BX Mycorise Pro to inoculate my tomato seedlings this year. Since about three quarters of a bale of that stuff went into my garden last year, I am hoping that my garden soil is reasonably well inoculated. I have also been applying some pulverized compost, which could help.

    Last year I did have to pick a bunch of tomato hornworms, but I always have to do that. Also removed a few green stinkbugs. My tomatoes did reasonably well, and grew out the top of my tall ReMesh tomato cages. Several of my seedless tomato vines grew taller than my head, which would make them about 6-feet high. We had a freaky hot, dry Summer and Fall here last year. Kind of makes me wonder what is in store for us this year.

    ZM

  • kevinitis
    Original Author
    12 years ago
  • zen_man
    12 years ago

    Hi Kevinitis,

    Thanks for the URLs for mycorrhizae products. I bookmarked them for future reference as possible soil amendment sources.

    ZM

  • carino2010
    12 years ago

    Now I am really confused. Guess I will just go with what Zenman said in his original post because the soil in the photo is such that I just cant wait to get my hands in it. ProMix with Perlite is what I will use to start my seeds.

    Thank you.