grass seed drying out

Discussion in 'Pesticide & Herbicide Application' started by mrkosar, Nov 10, 2007.

  1. mrkosar

    mrkosar LawnSite Senior Member
    from Ohio
    Posts: 664

    can someone explain the process of grass seed becoming a plant? i was just wondering how if you put down seed during a hot period and don't water it, it won't become a plant. why doesn't it just sit there until the proper conditions and then grow into a plant like dormant seeding? how is hot dry weather different than cold winter weather?

    i can understand if the seed becomes a plant, but the plant does not mature enough before the cold or dry weather then dies, but why doesn't it just sit there and then grow during hot dry weather. thanks.
     
  2. PHS

    PHS LawnSite Senior Member
    Posts: 724

    Since nobody has replied and this thread is about to go off the end unanswered I'll tell you the little I can remember offhand.

    I can't tell if you're asking more than one question but one reason why seeds expire faster in warmer weather than colder weather is that they are alive and respiring (burning stored energy). The warmer the weather the faster it burns up it's energy reserves and the less likely successful germination is going to occur. In cooler weather, physiological processes slow down and the seed can survive longer. Seeds can have a wide range of viability from a few days to many many years depending on the plant. I can't remember the scientific term but seeds that require fire for germination can survive very long periods, 50+ yrs.
     
  3. PHS

    PHS LawnSite Senior Member
    Posts: 724

    Now I think I understand your second question, why does it germinate right before cold weather if the cold weather is going to kill it? Turfgrasses may not be native to the area where you are growing them and they are being grown under artificial conditions, fert, irrigation, mowing, etc. So they may set seed and germinate at the wrong time for the environment it's growing in but it is right for it's native environment.

    In CA for example many plants set seed in the fall and germinate with the rainfall in early winter because that is when all the rainfall occurs, it's dry during the summer. If that plant was grown in a colder climate it will do the same thing but the seedling will get killed by the snowfall.
     
  4. Runner

    Runner LawnSite Fanatic
    Posts: 13,494

    Actually, it will just sit there and not do anythinguntil proper conditions come along. Proper condition + water in this case. As long as the seed is kept continuously damp long enough to soften the shell and the seed pops, it will germinate. Now, for it to pop, it must not be frozen. If it is frozen it will not crack (not commonly). Now, if the seed IS damp and pops, the soil(s) must be a consistent temperature of around 53 degrees (some just over) for it to viably take root. After that, the soil needs to be kept damp to allow the new root (then roots) to take up water. If this seedling runs dry, the plant is very apt to die. For dormant seeding, this is why you can throw seeds down in the snow, and they will not germinate. However, in the spring, when the soils reach that temperature, they pop and take root (with enough amount of soil contact - different subject altogether). Just like as was said in hot weather...the seed will lay there dormant during hot dry weather. Now, hot WET weather is a different story. Stuff germinates all the time- including crabgrass. Now pre-emergents (another whole different subject) work AFTER the plant germinates. What hppens, is after the seed pops, the young plant dies before it has a chance to take hold. Many people believe that pre m's prevent the seed from germinating...this is untrue. Some believe that pe m's kill the actual seed(s). This is untrue as well. I hope this helps and sort of clears some of the physiological questions of it.:)
     
  5. mrkosar

    mrkosar LawnSite Senior Member
    from Ohio
    Posts: 664

    thanks guys
     
  6. PHS

    PHS LawnSite Senior Member
    Posts: 724

    So I can buy my fall seed in a month when it goes on sale and throw it in my garage until overseeding next fall and still expect good germination rates?
     
  7. Runner

    Runner LawnSite Fanatic
    Posts: 13,494

    Yes and no. You can count on losing about 30% per year in seed viability.
     
  8. Marcos

    Marcos LawnSite Gold Member
    Posts: 3,720

    Nice honest discussion! Sorry I missed it.
     
  9. rcreech

    rcreech Sponsor
    Male, from OHIO
    Posts: 6,072


    Runner,

    That may be a little high (IMO)!

    I think if stored correctly (temp and hum)....it shouldn't change much in one years time.
     

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