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prairiemoon2

Perplexed when preparing cups for seed starting...

Hi,

I am trying to start some seed indoors. I am using plastic drinking cups. We used a drill with a 1/4" bit and drilled 4 holes in the bottom of the cups. We bought some potting soil, mixed it 2 parts soil to 1 part perlite, and filled the cups with this mixture. Normally, we use the sprayer at the kitchen sink to water them and drain before sowing. Our sprayer is broken, so we just held them under the faucet to water.

Well the cups filled up with water, the perlite has floated to the top and it took quite awhile for the water to drain. I am very perplexed as I haven't had this problem before. I looked at the bottom of the cups and there are 4 good size holes in each and they should drain. Also I added the perlite to 'improve' drainage, so I don't get it. I also don't understand why it is floating to the top. Plus when they were filled they were filled to an inch from the top and once the water drained, they are now half full. What happened?

I sowed seeds using this method a month ago and had no problem. The only thing different is a different potting soil and no sprayer at the sink. Actually the holes this time around are larger than the last time.

Not sure what my next move should be either. [g] I was thinking of just topping them off with sifted potting soil without the perlite and then misting them outside with the hose and sowing, but am still concerned with the drainage.

Any ideas?

Thanks

prairie

Comments (14)

  • 20 years ago

    Is your potting soil pretty dry(in the bag)? I used jiffy mix for my seeds and had to moisten it before using. I just poured a little hot water in the bag and stirred it well with a large wooden spoon. I got it just moist enough that it held slightly together when I squeezed some in my hand, but was still crumbly. It helped the soil to absorb the water after I planted. Since you've already planted, you could try bottom watering. Just set your cups in a shallow pan half filled with water(I'd use warm)and let them sit there until they soak up what they want. It may take a while. Good luck.

  • 20 years ago

    It is recommended to use seed-starting mix for seeds, rather than potting soil which is too dense. Then you won't have that problem.

  • 20 years ago

    Hi
    It sound to me that with your second attempt you used loam which is very heavy and dense. Blueheron say use seed starting mix but I have started to wonder if that is really necessary. I have used seed starting mix which is basically peat moss with the PH adjusted and perlite plus possibly other amendments. But when I was searching through Google, I found many sites when researchers were doing germination tests and they were using promix bx which is a coarse growing on mix.
    At the very least tho, I would start seeds with a soiless mix. It would be very light in weight compared to loam. Also, as per noinwi, you need to moisten peat moss with warm or hot water . I massage it through after adding the water.
    Cherry

  • 20 years ago

    The perlite is not necessary....just as it isn't (and shouldn't be used) in a potted plant.

    I agree that the water temperature has a lot to do with it....the hotter it is, the faster it will be absorbed into the soil (the peat portion of the potting soil is what is repelling the cold water).

  • 20 years ago

    Thank you all for your help. I didn't think the potting soil was dry. But we did use cold water when watering. We haven't sowed seed in the cups yet. We used Hyponex potting soil, not loam. Lots of people have recommended Promix, but I haven't found any locally and I don't want mixes that have fertilzer or moisture retention in them, so there are few choices. I called about a half dozen places, and looked on another 4 websites and just couldn't find what I wanted, so I settled for the Hyponex.

    Webkat, could you share your reasoning on why you don't recommend perlite?

    Thank you :-)

  • 20 years ago

    Hyponex Potting Soil is definitely not a loam. It is a peat based soil, but it includes sedge peat which is a very fine material. This is probably why you noticed that the water took a long time to drain through. The holes are fine, it is the soil that is slowing things up. You will have to decide whether this is OK for your plants or not, maybe with extra perlite or vermiculite.

    The shrinking that you see will happen with any potting soil, but some more than others. You probably haven't noticed in the past because you didn't pour on a whole load of water at the top to squash it down. Even with loam-based soils which are the least compressible, they will compact down a little. It is probably true to say that soils which compress more are less good, especially for seedlings. You want a soil that remains light and fluffy and retains lots of little air pockets. Perlite always retains lots of little air pockets because you can't compress it, at least until it crushes into powder. But perlite doesn't retain much water (for seedlings) and doesn't hold nutrients. Perlite plus a dense potting soil isn't ideal but it may be better than the potting soil alone. The ideal for most seedlings is an even loose potting soil so tiny roots can find water and nutrients without being drowned.

    Perlite floats to the top whenever there is enough water to float in. This is a pain. You can either water very gently, water from the bottom, put up with it, or not use perlite. I use it for cacti to keep the weight down and provide excellent drainage, but I try to bury it under a heavier top dressing.

  • 20 years ago

    Ahhh...thank you shrubs n bulbs! Now it makes sense. I am going to wait until it dries enough to just mix the perlite back in and top it off with more soil and water 'gently' with warm water, and then sow. I may look at the hyponex again and perhaps wet it with warm water as everyone has suggested, just to make sure it is moist enough before filling any more cups.

    Yes, I always notice some shrinking, but I usually spray to moisten so I don't see much. Who knew that not using a spray would make so much difference..lol.

    Since I already opened half of the bags I bought I guess I will just make do. Will be looking for another mix, if anyone in Massachusetts has a better source for something without additives.

    If I use the cups to sprout the seeds and quickly move them into their locations, then it won't be as much of a problem I expect, correct?

    Thanks for all your help everyone, mystery is solved! Buy better soil next time.

    :-)

  • 20 years ago

    prairiemoon2

    It depends where in Massachusetts you live....

    If you are willing to order online or drive up to Vermont, I can make a suggestion.

    No longer living in MA, but I know the area...

    Heather

  • 20 years ago

    hello ;there are several seedling media formulations which do not incorporate perlite (ie. metromix 360)....I find lots of merit with perlite,though, but one should evaluate this product per bag/lot/company. It should be a sterile item ...no smell/and white in appearance. I use a mesh screen (a childs play sand mesh) to add perlite to mixes that have Q.A. variations per given lot....
    If you use a clean plastic bag lined bucket/bin and prewet seedling mix then add dry seedling mix, working in with clean hands to determine the saturation of the mix (clumpability).You will still need to bottom water to determine how the media settles out....>>>sow and use dry mix to cover then use a fine sprayer to wet the dry topdress....
    (...probably written about somewhere....)

  • 20 years ago

    ..... agree with blueheron :(a good delph. grower...:)
    seed starting/seedling mix

  • 20 years ago

    I, too, got frustrated trying to find a fertilizer-free mix (more importantly for me, organic) and I make my own. I did see at Lowe's the "Miracle-Gro Organic" seed mix. I know, it seems an oxymoron, but it has poultry-poop-based fertilizer. This year I'm starting too much seed to afford premade stuff, otherwise I would use it--last year I used some fertilized mix without realizing it until later, and everything was fine. I'm interested in hearing why you want to avoid fertilizer? I'd read that it is unnecessary and might cause problems, but as I said, everything was ok last year and those flats didn't look different from the non-fertilized.

    I found this proportion on the internet somewhere, and it works well for me: 40-45% peat, 40-45% perlite, 10-20% soil/compost. In reality I just scoop perlite in until it looks right, and add an approximate amount of soil. The soil needs to be sterilized, and so does the peat if you're not buying pre-sterilized stuff.

    I pre-moisten the mix in a big container before I sterilize it in the oven or microwave, but also because it really made a mess to try top-watering. Bottom-watering didn't seem to work on dry peat, but I only tried for about an hour.

    I don't know why the water didn't drain well from your cups from one batch to the next, but I definitely have noticed that the perlite will float to the top when water is poured in--it's nice to know that using a sprayer can avoid this!. If, as others say, the drainage problem occurred because your mix is too heavy, you could grab a small bag of peat or sand from a home center and mix some into each cup, and/or add more perlite. I feel like the peat or sand would be the thing to add and not perlite, but I have no scientific reason behind that feeling!

    Good luck with your seed starting, I hope those seedlings will all be healthy!

    Here are a couple of links to other seed-starting recipes, none of which are the same as mine:

    http://www.organicgardening.com/feature/0,7518,s1-5-19-178,00.html

    http://www.gardenguides.com/TipsandTechniques/starting.htm

  • 20 years ago

    hello :-)

    heather... I am in Metro West near Boston. Vermont is more than 2 hrs from me pretty sure and the shipping for ordering online must really add significantly to the cost, so I guess that won't work for me. thanks though. :-)

    pickwick...I thought I had pretty good perlite, but guess I wouldn't know a good one from a bad one. It is white and clean. What are Q.A. variations? What is the purpose of the mesh screen for adding perlite? Yes, normally I use dry mix and fill, water with a spray, drain, sow, cover with sifted soil mix, mist. Yes, I need a good mix..again, hard to find a good one without fertilizer/moisture retaining ingredients.

    stagerat...yes, I am an organic grower too and would love organic growing mix. We have a local [40mins away] nursery, that is certified organic, and I called them and according to them, they are having a hard time finding something that they can use. Actually now that I think of it, I wonder why they aren't just making their own. Maybe they are and they just haven't said so.

    As for Miracle Gro, I just can't bring myself to support the chemical industries biggest suppliers. That goes for Scott's too. They make so many chemical lawn products etc, and I feel so strongly that is the wrong way to go, that I can't buy their products. I would rather use my money to support a company who is trying to get it right. There is a product called Coast of Maine but their prices are so high, I can't afford them.

    The reason I don't want fertilizer in the mix is because of the above reason and because the fertilizer they put in it is a synthetic chemical one and I haven't used that type of fertilizer in 25 years and don't want to use it now. I could get by with it just for seed starting I suppose, but it just goes against what I prefer to do.

    So, I suppose I can mix up my own, now that the winter is just about over and I can get outside again. It is a real pain mixing it in the house. Thankfully I had enough mix to get through most of my winter sowing.

    Thanks very much for your recipe and the links, I will look over the other recipes. I would really like to get away from peat all together, but it is really hard to figure out how to do that. lol Someone on another thread maybe, was suggesting mixing ground coconut husks in place of it. They use it and find it a good substitute. Something new to try. [g]

    Thanks everyone :-)

  • 20 years ago

    hello prairiemoon: re: perlite:an occasional human error at the packaging plant.(the product should be odor free/white...)just an advisory here...(nothing more...)
    I use a mesh screen to separate out the larger particles of perlite when I am not quite satisfied with the seedling mix (variations).I might add just a bit more (fine particle)perlite per batch but not much more....

  • 20 years ago

    Would free shipping help?

    I thought the coupon expired on April 1st, but I just plugged it in and it works for now.

    Enter the code JNA7009C and hit apply. (Make sure it gives you the free shipping) Do this after you add the germinating mix, etc to the shopping cart. I would also order online rather than calling; so you can get the code.

    Hmm... though the code I have for 25% off doesn't seem to function (at least not for their germinating mix.)

    I've used it both this year and last year. Though I can't guarentee if it's organic. I know some of their things are organic. You'll want to check out their website to find out.

    Oh yeah.... the website.... www.gardeners.com

    Their stuff tends to be a bit high on the prices, but take a look anyways.

    Search for: Germinating Mix