Getting the mix ready for sowing

To get the seeds ready for sowing we:

  • Select the species we want in the mix
  • Excluding very light seeds like orchid seed, we mix these together on a clean, smooth, dry floor
  • At ALL stages we try to retain all tiny particles in the mix as a teaspoonful of what looks like dust may contain hundreds or thousands of seeds

Having got the right seeds mixed together, we then prepare the mix for whatever drill we are going to use. We sow the seed using conventional agricultural drills. There are three challenges compared to drilling most agricultural crops:

  • Sowing low density seeds. Some of the seed is low density or ‘fluffy’ (such as Rough Hawkbit). This means it does not flow well in gravity fed drills as it tends to ‘float’ so does not get pulled down into the drilling mechanism
  • Sowing at a very low rate. We usually sow at between 0.5 and 2 kg/ha. This is a low rate which some drills may struggle with. Such a low rate also gives little room for error in calibration
  • Risk of the mix separating out. The largest seeds in the mix are about 500 times larger than the smallest. Such wide variation, combined with the jogging motion of the drill passing over the land, is likely to make the seeds separate out from each other, with smaller or denser seeds working their way to the bottom of the seed hopper first

We deal with these as follows:

  • Sowing low density seeds. We mix the seeds with a bulking agent that is dense enough to flow through a drill consistently. Before mixing in all the bulking agent, we always check that a small sample of the agent/seed mix does flow well through the drill. The agent we use is a wood chip cat litter (Cats Best OkoPlus Cat Litter). The cat litter will flow best if it is dry
  • Sowing at a low rate. Mixing in a bulking agent means we can overcome the problem of having a very low seed rate. For example, if we are drilling a 5ha field and have 10kg of seed, we may mix in 40kg cat litter. This means that we then end up drilling at 10kg/ha, which gives more room for error in calibration
  • Risk of the mix separating out. Taking the same example, we would divide the 50kg of seed/bulking agent mix into five separate bags, one for each hectare. We drill one hectare then add another 10kg bag. This means any one volume of seed is in the drill for a shorter period of time so is less likely to separate significantly. Also, if there is any separation, then each species will at least be on five parts of the field rather than predominantly in one area