Starting seeds indoors with soil cubes

 This is the Soil Cube Tool, designed and sold by 

Clayton Jacobs. ( www.soilcube.com )  

This is a pretty simple design that is practical and

 easy to use. Basically inside the white squares are 

metal plates attached to the bolts. When you push

 down on the handle the plates compress the soil

 medium into cubes and leave a divot for seed
placement. The springs push the handle
 back to the starting position. 

These are the components of the soil medium. The ratio is:

          3 parts peat moss

       2 parts compost

          1 part garden soil

1 part sand 

  1 part perlite

           Add lime if desired

You can also add fertilizer at this point if you wish. 

I would personally use worm castings and some compost tea. 

You can tweak this mixture for making soil cubes 

but I would stick to the ratios and use medium

 similar to the products in the picture. 

I mixed everything together dry in this large "hose" bucket. 

You can get these at your local box store for $4. I then split 

the mix into three buckets so I could make sure it gets mixed 

consistently. Add just enough water to get a thick oatmeal 

consistency. Once the first 1/3 is mixed add more dry soil 

mixture and repeat. I make a lot of this once a year, saves

 time and it doesn't hurt to have extra.

 Press the tool into the mix and press it against the 

side just filling the inside of the tool with the soil mixture. 

Press down on a hard surface, hold for a second then push 

the handle through the tool and the cubes will fall out. 

It takes a bit of practice to get consistent cubes but if you

 mess up just crumble the bad cube back into the mix.

Here is a close up of the cubes when they are done. 

They hold together very well and readily absorb water. 

Here are the same cubes growing tomatos. 

We have 188 cubes started right now. We are growing

 8 types of tomatos, 7 types of peppers, eggplant,

 celery, leeks, 3 types of onions, broccoli, cauliflower, 

brussel sprouts, green cabbage, red cabbage and kohlrabi. 

Place the cubes in a tub like this, it is very 

easy to move them without handeling them. 

You can pour water in the bottom of the tub which 

the cubes will soak up and wick through the cube. 

Don't let them sit in a pool of water, 

use just enough to saturate the cubes.

This is many varieties of lettuce, spinach, cilantro and amaranth. 

They are growing in trays filled with the grow medium. 

You can grow salad greens all year round without 

them bolting or going bitter in the heat.

Here is the whole set up. The lights are full spectrum

 4 foot fluorescents hanging on chains from a stainless

 steel shelving unit. The lights are on a timer set to come

 on at 5am and go off at 9pm. I have heating pads under

 the peppers and tomatos to help them germinate. I use a 

one gallon hand pump pressure sprayer to mist the cubes 

gently so the seeds are not disturbed.