Seed Starting Blocks

What are Soil Blocks?

Soil blocks are small self-contained blocks of lightly compressed soil. Seeds are sown directly into a hole made in the block. As the seedling grows, its roots reinforce the block and undergo air-pruning. When it comes to planting out, it’s as simple as popping the block in the ground. No splitting, no teasing out roots ...no fuss!

Soil Blocks have several advantages.

1. Seedlings grown in soil blocks undergo minimal root disturbance during transplanting, allowing seedlings to establish quickly following transplanting.

2. Each Soil Block Seedling is ready to plant as it is. No need to divide seedlings and tease apart roots, saving you time.

3. Reduced plastic waste!

Soil blocking in a nutshell!

Sustainable method for raising organic seedlings.

Natural air-pruning of roots produces healthy root systems.

Plants re-establish quickly following transplanting due to minimal root disturbance

How to make Soil Blocks at home

We’ve put together a guide for the home gardener to get the most out of soil blocks.

If you only need a few seedlings you can form soil blocks using only your hands. A second low-cost option is to use salvaged materials and make your own soil blocking tool. The third option is to find a Ladbrooke Soil Blocker.

Soil Block Mix Recipes

The key to starting healthy and strong seedlings in soil blocks is the soil block mix. The mix provides the space for healthy root growth and nutrients for the growing seedling.

You probably already have all the ingredients you need!

Compost, compost and more compost!

Soil Block mixes are mostly made up of compost, with a little sand, or coir fiber, to reduce compaction and assist drainage. Worm castings are also a great beneficial additive.

You will need to experiment a little to find out what mix works for you.
There are many recipes out there.
Here is one recipe from Milkwood and one from Ladbrooke.

A reliable Soil Block Mix Recipe:

4 parts sieved compost
- Either from your own compost, neighbours & friends, community garden or certified organic compost from a garden centre.

1 part worm castings (optional)
- This works well as a binder and provides nutrients.

1 part coir-peat (soaked overnight in cold water, or just add hot water)
- Helps retain moisture and nutrients.

A sprinkle of rock dust & blood & bone (optional)
- Provides minerals and nutrients. May only be necessary if your compost is lacking minerals and nutrients.

Like any recipe, you can experiment and optimise it to suit the ingredients available to you.

Preparing the Mix

1. Mix together the dry ingredients.

As a guide, 5 litres of mix can make 30 blocks with the Ladbrooke Mini 4

Set aside some of the dry mix (1/4 or 1/2 of your total if it is your 1st time).

2. In a container with a flat bottom (e.g. old baking tray or large tub), add 1 part water to 2 parts dry mix and mix well.

You are after a consistency of sticky mud or porridge. Add more water until the right consistency is obtained.

3. To check that your mix is of a good consistency simply squeeze a handful.

Drops of water being squeezed out of the mix? – Great!

A stream of water running down? – add more dry mix.

No water dripping out? – add more water.

Making the blocks

1. Push the Soil Blocker down into the mix until you see some water coming up the top of the tool (charge several times if necessary)

We find that for efficient ‘charging’, pile your mixture 7 to 8 cm high.

2. Twist the tool slightly (to remove any suction) and lift.

3. Scrape off excess mix on the bottom of the blocker.

4. Eject the soil blocks into your desired tray.

Seeding & care

Fill each block with one or two seeds.

Cover the seeds with a thin layer of worm castings or compost.

Gently mist with a spray bottle until the holes are filled with water.

Keep soil blocks moist by either misting with a spray bottle or soaking soil blocks in shallow water.

The roots of the seedlings will start to hold the soil block together, when you see roots on the side of the blocks you can start to water with a seedling.