Seed Bomb Sowing Time – When To Sow Seed Balls In The Landscape

Seed Bomb Sowing Time – When To Sow Seed Balls In The Landscape

By: Laura Miller

Were you disappointed in the germination results when youplanted seed balls? This novel approach for sowing seeds has been used to repopulatehard-to-plant areas with native species. The concept sounds promising, butgardeners are reporting low germination rates when using this method. Thesolution lies in choosing the correct planting time for seed balls.

When is the Seed Ball Season?

If you’ve never used seedballs, it’s an interesting concept. Gardeners either purchase or make seedballs by stirring humus, clay and the desired seeds together. Small balls areformed by rolling the mixture between the hands. The seeds balls are then tossedinto the landscape, which is why they are sometimes called seed bombs.

The seed ball protects the seeds from the hungry mouths ofsmall animals and birds. Rain breaks down the clay and the humus providesnecessary nutrients for the young seedlings. This sounds interesting, but thereare a few snags to work out when using this method:

  • Native species have a difficult time competing with established plants, especially invasive ones. Knowing how to plant seed bombs is the key to success.
  • Seeds from native species of plants which grow in northern U.S. climates often require a cold period. The solution is to stratify seeds or plant at the correct seed bomb sowing time for the species.
  • When dispersing seed balls, it’s easy for them to land in the wrong microclimate for the species. Know the ideal environment for the species you are planting and strive to place the seed balls accordingly.

How to Plant Seed Bombs

To reduce competition and give native species the chance togerminate and grow, site preparation is often necessary. The area can be mowedand the soil tilled or worked up. On steep terrains or hard-to-reach sites,smaller areas can be weeded and worked by hand. Vegetative killer can besprayed or a well-controlled burn can be used to clear the site.

Rather than tossing the seed bombs, place them throughoutthe area by hand. Allow adequate space for the mature size of the species. Foroptimal germination rates, push each seed ball halfway down in the ground.

When to Sow Seed Balls

Timing is an important aspect when planting seed bombs. Ifyour germination success rate has been low, here are a few suggestions to try:

  • The best seed bomb sowing time for most annuals is in the spring after danger of frost. Perennial plants, like milkweed, do best when planted in the fall so the seeds experience a period of cold.
  • Avoid spreading seed balls during the heat of the afternoon. Try sowing in the evening or before a rain.
  • To ensure the seed balls land and remain in the correct microclimate, don’t plant during windy weather.
  • Plant during a rainy season whenever possible; otherwise, supplemental watering will be necessary.

If you’re seed bombing efforts haven’t paid off in the past,hopefully these suggestions will help. In the meantime, keep up the good workin your efforts as a steward of the planet.

This article was last updated on


Guerrilla GardeningWith Seed bombs, Seedballs and Mud balls

An ancient idea for growing plants without digging or tilling.

Sometimes a no-dig gardener's gotta do what they've gotta do and if that means chucking things around and hurling stuff everywhere well so be it.

I'm talking about these vacant, unloved public spaces that some poor schlepper has to sneak out and beautify with flowers and vegetables.

You know who I'm talking to, you know it's you. and you know if it's not you, then it will be soon.

Without further ado, here's what you do.

* 5 parts dry clay
* 3 parts dry organic compost
* 1 part seed
* 1 – 2 parts water

Clay comes in all colors and quality. Red potter's clay is perfect and can be bought online. Also garden centers, craft shops or farm suppliers sometimes sell clay powder.

Often if you dig down under your top soil to the subsoil, you'll find clay. Make sure you go deep enough so there's no sign of weed seeds. Excavations for building sites, ditches, drains or roadworks may also yield clay. This clay might need to be dried in the sun then any lumps smashed out of it with a spade or brick.

After mixing together all of the dry ingredients, slowly add water to the mixture to make a stiff dough. Add only enough water so that the mixture sticks together, but you don't want a dry, crumbly mix so that it won't role into balls.

When you get your mixture just right, make it into cherry or marble sized balls.

The next step is to dry them completely as quickly as possible to prevent the seeds from premature germination. With good weather the drying process should be around 48-72 hours. Some people dry them in the sun, but best not to as this could kill the seeds if they get too hot.

That's it. Get yourself and any other willing troops ready. Your seed bombs are smokin' hot ready to sprout into action.

Actually they are hard and cold, so keep them that way until you are ready to do your random hurling. And another actual fact is that before they sprout they will most likely go through a sleep-over amongst some weeds. Fall/Autumn is the popular time for seed ball distribution and they land on the earth and wait for some rain to soften them.

Random notes on being a guerilla gardener, mud ball/seedball/nature bomber.

  • The clay stops birds and mice from eating the seeds. It also stops the seeds from blowin' in the wind. A hard clay ball can be tossed over a fence and a long way. Once the seeds sprout inside the balls, they will grow safely until they send their roots firmly into the ground.
  • Once rain or some moisture softens the balls, the clay holds this dampness in to help the seeds germinate. Depending on your weather and what seeds you use, your plants will sprout and start to slowly grow and come springtime, they will bloom and produce.
  • Don't put too many seed in each ball otherwise they may crowd each other out when they grow. Two or three seeds are good, but a few more if they are small flowering plants.
  • A bicycle is a particularly good way to spread seedballs across the landscape. Nothing wrong with cars, trains and buses too. Especially for motorway embankments. For any local wastelands, fill up your bag and take a stroll.
  • Good fun for kids to make. They'll also go wild with delight with hurtling their seedbombs.
  • Some seedy choices (or some choice seeds if you prefer): Native and bee-friendly wildflowers milkweed to encourage monarch butterflies herbs vines such as melons, cucumbers, zucchinis, pumpkins tomatoes in fact any and all of your favorite flowers and veggies.
  • Some veg are a bit wimpy when it comes to hardship. The likes of lettuce and fast growing, leafy greens often miss out on regular watering so can give up and go to seed. Having said that, I've seen the odd chard, silverbeet and kale that have thicker leaves, profusely growing amongst some council spaces and roadside strips.
  • Berries and even trees can be grown this way, but you're pushing your luck a bit because they need longer to establish and grow to a decent size before producing. Yes it would be lovely to have lemon trees and blueberries, but you have to contend with the fact that over the years your patch might be developed into a building site or a road-widening scheme.

Who knows where your seeds may land and what will grow!


You will need a certain amount of Mother Nature's cooperation to successfully seed bomb. You may have to contend with iffy weather, wayward walkers, swerving vehicles and most fearsome of all — bureaucrats! "Section 2, Sub Clause 3, Item 4. thou shall not. blah, blah, blah."

Otherwise those naughty seeds will grow their little hearts out for you and all the world to see.


2. Mix The Compost, Clay and Water

I thought this was the most fun part of making seed bombs. It was therapeutic to get my hands dirty in the off-season!

Start with equal parts compost and clay. The more compost, the better!

Pro tip: Feel free to use garden gloves, as this does get a little messy. I don’t mind getting my hands dirty but wish I had taken my ring off!

Start with one part compost to one part clay and mix it together with your hands. Add water gradually to get a soft texture that is easily molded. Once I had the right consistency, I kept adding more compost, clay and water until I had enough for about 12 seed bombs.


Will These Seeds Grow?

You can test old seeds—from last year or years past—to determine if they are still viable.

Count out ten seeds and place them on a double thickness of moistened paper towel. Roll up the towel and place it in a plastic bag and seal it. Put the bag in a warm—about 70° to 80°F—and well lit spot. In six to ten days open the bag to see how many seeds have sprouted. If 5 seeds have sprouted you have 50 percent germination.

Most new packets of seed have a 90 percent or better germination rate. You can count on almost every seed to sprout.

But if you have old seed and the germination rate is just 50 percent, you will want to plant twice as many seeds to make up for the reduced rate of germination.

For more information click on these two articles:


Watch the video: Seed Bombing: How Thailand Plans To Restore Its Forests