Unlike other brands on the market, the ROOT!T expanding plugs do not have netting at the base. This design allows the tap root to grow naturally out of the base of the plug unrestricted, avoiding root strangulation. The plugs are held together with a paper wrap which is biodegradable and will not fall apart. It will allow the roots to penetrate the sides and still keep the plug in shape. The ROOT!T propagation plugs are available in either CocoCoir or Peat varieties..