Planting Seeds in Soil Blocks

Soil blocks are generally planted with just one seed to a block. (There are exceptions which I'll talk about later). While it sounds like a lot of tedious work, it really is quite easy to do and goes much faster than it would seem from the following directions. A little practice and you will have your Mini 20 sown in no time. If you are planting larger seeds that you can pick up with your fingers it will go even faster.

When planting Mini 20's I try to plant a whole set with one type of seed, then just lay a plant label along side it. However, if I really need to split them up, say I only want to plant 10 cauliflower and 10 broccoli seeds, I could lay a label next to the top of the block of Mini's and say plant the first two rows, then tuck a thin label in the crack to divide the group and plant the next ten blocks. But I am always consistent. I file paperwork to the front of the divider, so I sow my seeds the same way. That is I place the label and sow the seeds in front of it. Some people make a little chart on graph paper and label the rows. What ever will work for you.

To get started, pour a few seeds out into shallow white ceramic dish. White is the best for being able to see small seeds. If you are planting Snapdragon, Petunia or other very fine seeds you might want to have a magnifying glass handy so you can see them.

Now take your sharp pencil or a toothpick and dip it into some clean water, shake it off if a really big drop of water forms on the point. Then touch the wet point to a single seed. Most of the time the seed will jump right over and stick to the pencil point. Carefully transfer it to the first soil block and touch it to the soil in the depression.

I have a set routine when I am seeding soil blocks. I always work from left to right and I start on the row farthest away from me. If the seeds are really tiny and especially if they are black you can't see them once you set them into the soil. When that is the case I'll set another pencil, toothpick or label down beside the blocks, pointing to the row I'm working on. Then I count as I transfer the seeds to the blocks, so I know which block will get the next seed.

Should you cover the seeds? For really small seeds I don't usually bother. Some seeds need light to germinate so covering them would defeat your seed starting efforts. Other seeds want to be in the dark. (Your seed packet will usually tell you if the seeds should be covered or not). If they don't need darkness then I tend not to cover. If you do want to cover your seeds try rubbing a little of the (dryish) potting mix through some window screen and don't put it on too thick.

Once you have covered or not, mist the blocks with a very fine mist of water to help settle the seeds down into the soil and make sure they are damp so they can begin to germinate.

Like I said in the introduction I use the Mini 20's to start warmth lovers on my heating mat in early spring. For that I recycle styrofoam meat trays. I also drape a sheet of plastic around my grow lights and heating mat to help keep them warm and humid.

At other times I recycle plastic containers, especially the large salad boxes. These have a tight sealing lid that comes completely off the box. To use these I turn the lid UPSIDE DOWN on the table and make my soil blocks on it. Then after planting and misting I carefully set the box on top of the lid and seal it. This keeps the blocks nice and moist. Outdoors I keep the germinating seeds in partial shade along the east side of my house where I have set up a plant nursery. As soon as there is a green shoot or two I carefully open the box to let in a little air. I keep the box over the seedlings for a few days, but I set it at a slight angle to the lid, to let a little air in but still protect the seedlings. At this point they will need misting once or even twice a day if it is very warm as these tiny blocks dry out quickly. (I have to put a rock on top to keep them from blowing around in high winds)

As soon as they are sprouting I transplant fast growers like cole crops into larger blocks. Small flowers can stay in the little blocks for a week or two.