Students make seed balls as part of a seed propagation session during the horticultural science summer institute at North Carolina State University.
Making seed balls – or seed bombs as they are sometimes called – is a fun craft for children and a unique project for garden clubs or similar gatherings. These whimsical seed bundles are a great way to start growing more pollinator-attractant plants.
The Extension Master Gardener Volunteers of Durham County, North Carolina, have made seed balls as an activity during a 4H camp for children. While there are many recipes available and even ready-to-order seed balls online, the general recipe that the Durham Master Gardeners use is shown here.
Former Horticulture Agent and Field Faculty for the North Carolina Cooperative Extension Service, Michelle Wallace answers some questions about seed balls.
How do seed balls work?
Students mix ingredients on the table and then shape the mix by hand into one- to two-inch balls.
The thickness of the seed ball helps to conserve moisture as the seeds begin to germinate. As the ball breaks apart, the small crumbs are heavy enough to hold seed in place and offer a nice start for the root system.
Is there any preparation that should be done to the area where you will throw the seed balls?
The better the soil, the easier it is to establish the plants, although some plants, such as wildflowers, are naturally adapted to germinate under less-than-ideal conditions. It is much harder to have success in areas where there is a steep slope, because the seeds will wash to the bottom of the slope or away after a big rain.
What flower seeds are the best choice for seed balls?
Bees need high nectar-producing plants. Plants that produce flowers generally have yellow pollen which will attract bees. Yellow is one of the colors that bees can see. Wildflower seeds usually contain a nice mix of annuals and perennials that are attractive to bees. Gardeners can cross-check seeds using the Pollinator Partnership’s Bee Smart mobile app
that helps gardeners select the best native plants in their area to attract bees.
When is the best time of year to make and throw seed balls?
Seed packets generally have recommended planting times listed on the back of the packet for each region of the United States. Spring and fall are good planting times for seeds. Some plants like poppies are a great seed to use in a seed ball, but they need a cold spell to germinate. So they need to be seeded in the fall and allowed to overwinter so they flower in the spring. Also, germination rates decrease from year to year, so use seeds the same year that you buy them.
Where do you get the clay soil that is used to make seed balls?
You can use clay soil from your yard to save money. If you’re in an area that does not have clay soil, you may use a cheap, clay-based, unused kitty litter. Clay from an art supply store is another option, but expensive. Clay soils have more air pockets and hold more water.