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. more details are given at Using Compost
This page describes how to make Seedballs
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 but we give an alterative to clay using flour.
Making Seed Balls
This activity is suitable for use at those parts of the year when seeds will germinate outdoors usually
April – June in the UK but check the labels of the seed to be used. Two recipes are given. The traditional clay ball and a flour and compost ball which avoids the need to order clay.
I normally make seedballs in groups of 16 – 20 children
with each child making three balls if they are paying to participate and making the bombs to take away at the end of the session. However, if the plan is to seed bomb a school garden each student may only make one bomb and the bombing will
take place in small teams with each team bombing a marked off section of the garden. When the seeds have germinated the students can see how effective they have been in covering the whole of the target area.
Costs of 100g of seed will cost about
£20 -£26. The number of seeds per gram will vary considerably depending the plants in the mix e.g. a gram of Yellow 20 1 g of Flag iris will contain approximately 20 seeds while 1-gram Common centaury (Centaurium erythraea)
will contain approx. 80,000 seeds.
The compost used in this activity can be purchased from the local garden centre, but it is better if homemade seed compost is used as this will demonstrated a use for the compost produced from
the kitchen ,fruit and garden waste. Following the link to find a recipe to make seed and potting compost ……………………………………….
It saves time and wastage
if the teacher/trainer has weighed the seed in advance and either dispensed into containers or has prepared pre-marked plastic measures one for both seeds and compost.
Requirements (makes 16-20 balls):
native wildflower seeds (fewer seed may be used depending on their size and the area to be covered)
- 200g dry, organic seed or multipurpose compost or homemade seed compost.
- Clay Seedballs: 85g powdered red pottery clay
(5kg approx. £11.32). Use natural rather than air-drying clay as the latter usually contains nylon fibres
Seedballs: 125g of cheap flour
- Plastic measure scoop/measure for the compost (200g) and seeds (25g)
- A mixing bowl
- Plastic tray
- Grease proof/wax paper for drying the
- Disposable vinyl gloves and plastic apron (optional)
Making the clay seedballs
- Wearing the gloves weigh or measure the 25g seeds and the 200g compost into a bowl
or plastic container
- Gently mix the seeds and compost with a spoon or by hand.
- Add the dry red clay and mix again.
- Slowly add water while continuing to stir and mix the seeds, compost, and water to form an evenly
- Line the plastic tray with wax paper
- Hand roll the material containing the seeds, compost and clay into a ball of about 25mm in diameter
- Put the seed balls on the tray and allow to airdry
for at least a day. If the seed balls are to be taken away from the session before they are dry gently wrap them in the wax paper to air dry at later.
- Once the balls are dry throw or drop them at onto the patch of prepared soil
Flour Seed balls
- Mix together approximately 220g of compost and 125g flour in the bowl
- Add 25g wildflower seeds mixing well.
- Add water, a little at a time, mixing
by hand until the mixture becomes sticky like dough and forms a ball.
- Divide the dough to make seedballs about 25mm in diameter
- Put the balls on the tray and leave to air dry for at least a day
The seedballs can be put,
dropped or thrown onto the area being seeded. If thrown the flour seedballs are more likely to breakup on impact with the soil than those coated in clay and are best thrown immediately after a shower or when rain is expected.