4. Feb, 2019

Compost Seedballs

Compost Seedballs

Seed or earth balls are used for “seed bombing” where the balls are thrown or dropped by hand   or from the air into the area where they are to germinate .

Sowing Seedballs directly in the field is a technique used in ancient Egypt and  by North American First Nations’ tribes and is now being used  for the large-scale regeneration of land.  

Seedballs dropped from the air mat contain the seeds of trees to create forests while those thrown by hand  are often used for planting wildflowers in abandoned vacant and neglected areas of towns and cities. They also provide a means of sowing wild flowers in school grounds and allotment sites.

Clay based Seedballs

The conventional Seedball is  made by  rolling the  seeds in a ball of  compost which is coated with a layer of  wet clay  or,  in a variation of the method, the seeds, compost and clay are all mixed together when making the ball. The compost and clay act as a carrier for the seeds so they can be thrown into inaccessible areas. Each seed ball provides the seed(s) with a mini ecosystem. Where the balls are made commercially, they are normally about a 1cm in diameter a size which makes scattering, but home-made versions tend to vary and are often larger.  The clay provides a  shell   protecting the seed and nutrients  in the compost from  predators e.g.  as birds,  ants and rodents.   However, as this technique  will normally require the purchase of clay there is an alternative  suitable for allotment sites and schools using flour instead of clay. 

The completed balls  are then placed or more often thrown into the garden or  ground where it is hoped the plants will grow. There are techniques where the seeds are spread form aircraft, but my view is that this is unlikely to be used on  allotments or school grounds and  domestic gardens,  so no further details are given here.   Seedballs can also be used for planting in pots and raised beds.  The seeds will remain dormant until their environmental needs are met. When enough rain has permeated  the clay, the seeds germinate with the initial growth of the plant being helped by the nutrients and minerals in the compost.  After about three weeks the first seedlings work their way through the seed bomb and root into the ground below.  As they grow the seed bomb begins to dissolve. There are variations to the basic recipe one used by  Seedballs (https://www.seedball.co.uk/ ) are made with the addition of  chilli to help protect  the seed from predators.

Flour and Compost Seedballs

Home, school and allotment composters may like to make seedballs using their compost without having to purchase clay. Flour Seedballs  provide an easily made and cheap alternative to the tradition clay encased ball. These are more likely to disintegrate if thrown  spreading the seeds and ensuring a wider coverage of the area and seed bombing might be more fun for children. However, it does mean that the seeds will lose their compost packing  on impact and germination may be better if the seeds are put on the soil, raised bed or flower pot.  More information on www.carryoncomposting  Using Compost