I do not know the difference between 1). dried tall grass (5 feet), 2). Straw and 3). Hay. Can I use any of these for (the brown carbon portion) composting or do I run the risk of of sowing weed seeds? Thank you for your help. - David



  • JodieDownUnder
    JodieDownUnder Posts: 1,483 admin

    Hi David and welcome to TGN. When you get a chance have a look at the forum rules etc. also in the blog section and in the Academy there might be some handy information for you.

    A good compost brew relies on brown carbon(brown)and nitrogen(green)at roughly 30:1 ratio. Brown includes what you’ve listed above + newspaper, sticks no thicker than your finger etc and green is lawn clippings, fruit & veg waste, manure etc. If you get the ratio & moisture right the heat thats involved in the process will render the seeds useless.

  • Monek Marie
    Monek Marie Posts: 3,537 ✭✭✭✭✭

    Hi David, Welcome to TGN!~

    Without a photo I am not sure what your 5 foot tall grass it or how much seed it might have.

    Hay would be a combination of several different grasses, some of which might carry a lot of seed or some other sort of other weed.

    Straw has been planted for the seed and has had the seed removed from it to be used for feed so it has a lot less seed, just what might have been missed. Straw is preferred for mulch so it will not spread any grasses or weeds. If I can find old straw at a discount price I will use it

    Hay can grasses can be used you just need to make sure the compost hits a certain heat so that any seeds are killed. I also let a compost with hay sit a little longer to make sure its "well done" I use mostly hay in compost as I usually get it free.

    @JodieDownUnder's compost ratio in tight on. And for compost its all about getting a good temp to kill an seed so if you do that you should be ok using hay.

    Another thin to look out fo in composting is clean maerial that does not have a lot of chemicals so I usually know my hay source if I use that. Same with leaves (and leaves make a great composting material)

  • Torey
    Torey Posts: 5,641 admin

    @2davidrath Welcome to TGN's forum.

    You can type compost into the search bar here in the forum and see what comes up.

    Or as @JodieDownUnder suggests, check out the Academy. There is a course on vermicomposting, one on nutrient dense soil and one on bio-intensive gardening; all of which might have some good ideas for you and your new compost.

    When you have a minute, let us know where you are from in the Introductions section. There might be someone one fairly local to you to connect with.

  • Hassena
    Hassena Posts: 345 ✭✭✭

    Hi @2davidrath

    There is a potential for introducing weed seeds to the compost. The compost needs to heat up a lot to kill weeds seeds. During the curing phase of compost, the weeds may germinate. Then turn them back into the compost pile. This usually is enough to kill the young seedlings so when the finished compost is put on the garden, it is mostly weed seed free.

    As long the grass, hay or straw is dried, it is considered carbon.

    If you plan to grow tomatoes or peas, be cautioned that the hay and straw may have residual herbicides preventing germination.

    One way to test the compost is to do a germination batch test.

    Also, I echo all the above comments. =) Especially about the vermicomposting class.

  • VermontCathy
    VermontCathy Posts: 1,980 ✭✭✭✭✭

    Make sure you don't compost any hay or straw that may come from a field contaminated with aminopyralids, such as "Graze-On" brand.

    These weed-killers are harmless to grass and the cattle that eat it, but can devestate the broad-leaf plants that we grow in our gardens. And once your garden is contaminated, it will be years before it breaks down.

    You should check to be very sure that your source of hay or straw did not come from a field where aminopyralids were used. Unfortunately, some farmers aren't aware of the problem, and may be selling hay or manure that is contaminated.

  • nicksamanda11
    nicksamanda11 Posts: 754 ✭✭✭✭

    Lots of good info here.

    I tend to just throw it all in with abandon. I'm more of a David the Good kinda gardener😁- breaking all the rules including compost rules. Who's afraid of meat?!?!

  • jowitt.europe
    jowitt.europe Posts: 1,454 admin
    edited March 2022

    @nicksamanda11 I like your comment! Me too. I throw everything into a compost heap and use for gardening what comes. It works. Actually very well. And, as there are seeds left in compost, many plants come without sowing: dill, savory, camomile, calendula.... however, I do not grow vegetables commercially. Only for our own use.

    @2davidrath welcome to the network! I am sure you will finds lots of useful information here. And share yours!

  • SuperC
    SuperC Posts: 951 ✭✭✭✭
    edited March 2022

    @2davidrath Hay may have seeds, that’s why I use straw. Straw deters weeds and allows homes to thousands of microbes, snakes, spiders, among other happy critters. The tall dry grass may be useful as long as the seeds at their tops get removed, who wants more weeds to pull?! I mean, less weeds in compost is better and more user-friendly. When you place straw onto the compost or onto the garden, make sure to completely soak it providing moisture to what is underneath. Let us know what works for you, and what is helpful. I agree with @VermontCathy, make sure to verify where the hay and/or straw comes from. before just tossing it onto your beautiful compost that you've been diligently working on to get its optimal results.