Indoor Seed Starting with Soil Blocks

 

Are you ready to jump in and start planting things, but the ground is not warm enough yet?

It is a great time to start seeds inside to get a jumpstart on the growing season! I am excited to share one of my favorite ways to start seeds using soil blocks.

Why Start Now?

Cleaning up and mulching your garden now and starting seeds ahead of the season now is the best way to make it easy for yourself in the Spring. By adding minerals, compost, and mulch to the garden now, you are allowing time for everything to settle into the ecosystem. It is also great to get your soil covered to avoid those early season weeds that creep up on you before you have even started planting! The addition of mulch, especially a dark-colored mulch, will also help warm up the soil earlier and keep it insulated and moist so the microbes can wake up and get active. Find out more about growing your own food here.

The Benefits of Soil Blocks

I find that using soil blocks has many advantages to plastic celled trays. My main goal in the early stages of the plant’s life is to reduce stress because these early weeks are determining the future yield now. With cells, if the plant is left in it too long, the roots start wrapping around and the plant can become root bound, which leads to a decrease or halt in new growth. Then, when you pull it out of the cell, you have to cut the roots and mess with them, which is pretty stressful to the young plant.

With the soil blocks, the roots are air pruned and don’t wrap around the block. Plus, when it is time to transplant, you can just pick it up and put it in the ground without accidentally breaking or damaging the top of the plant – as I have been guilty of when trying to remove starts from the cells.

Another benefit to using blocks is that you are reducing plastic waste creation.

Inoculate

But regardless of if you use cells, buy plant starts in pots, or make soil blocks, it is important to inoculate your seeds. It’s like colostrum for the baby plant that helps it with digestion so it can access more nutrition immediately.

I like to apply the inoculant to the seed directly, so it is there at germination. You can also dust it on the roots before transplanting, or make a drench and water the holes before setting the plant start in it. The important thing is to have root contact for the full benefits.

The easiest way to inoculate your seeds is to open the seed packet, add a pinch, close the packet, and then give it a good shake. That is it! It is ready to plant or hydrate. There are a few good companies out there offering seed inoculant – look for something that includes endomycorrhizal species in the mix. There is a product called BioCoat Gold that has done well for me.

Soil for Seed Starting

When starting seeds, I usually like to make my own blend that includes some soil, compost, and sand, but a good organic potting or garden mix will work well too. Just make sure you read the ingredients on the bag, a good company will be transparent. You want to avoid brands with plastic or styrofoam fillers, chemical fertilizers, or waste from confined animal operations or sludge. If the product smells really bad or indicates to wear gloves – don’t buy it! I like to find one that includes worm castings, compost, beneficial microbes, and kelp meal. It is also good to include a little garden soil with clay content to help with holding the form of the soil block, as well as prepping plant roots for the real world.

To this, I add a mineral blend, rock dust, and kelp meal (if not already in the blend). I really like kelp meal because it has good minerals and growth stimulators for the young plants.

Then, once it is all mixed well in a tub, I moisten the soil blend and massage it until I get a thick putty or peanut butter consistency. It is best to do ahead of time, up to an hour, to let the mix get hydrated well. Make sure you start with more dry soil mix than you think you need because it will be compressed and go fast.

Making the Blocks

Once the soil is hydrated and ready, go ahead and get your trays ready to set the finished blocks in. My preference is to use a two-tray system, one mesh and one solid. I insert the mesh tray inside of the solid tray, which allows me to remove the blocks in case of overwatering or block crumbling. It also allows me to water from below to encourage strong roots.

The next step is to gather the soil in a pile and push in the soil blocker tool. Wiggle and twist it to make sure all the spaces are filled. Keep lifting, regathering the pile, and repressing the tool as needed. Once the cells of the blocker are stuffed, scape off the excess until it is smooth. Then push out the cells into the tray and space them about a 1/2 inch apart.

Continue this process until you have filled your trays.

 

Planting the Seeds

Once your blocks are ready, it is time to plant your seeds. My favorite soil blockers include a piece that makes an indent in the block for the seed – which saves tons of time! If you have already mapped out how many blocks of each seed you need, place two seeds in each block divot. Then take some of the loose soil mix and cover the seeds. Tap it in softly, you want good soil contact, but you don’t want to pack it hard.

Now you are ready to place your trays in a warm place in your home or even use a heating mat to help speed up germination. Once the seeds sprout, place them under a grow light and keep them watered regularly. I use a spray bottle in addition to my regular watering as I find the tops dry out quickly with the heat in the house. Keeping the top moist in the beginning is critical to getting good germination. Add a crystal and positive words to your water bottle to improve the structure of the water and give good energy to your plants. 🙂