Monday, February 7, 2011

Towards a Greening of the Garden

Now, at first thought, gardening IS green, isn't it? After all, stuff grows, and to grow requires chlorophyll which IS green... And in the modern sense of "green" we do seek to garden in harmony with the earth, using "organic" principles, avoiding strictly chemical fertilizers in favor of compost and manure and the meals made from bone and blood. We pick off bugs, or very judiciously use water with a bit of soap or diatoms.

...BUT like many gardeners and growers, we had become accustomed to the ubiquitous plastic pot and six-pack, and the plastic flat which group these smaller containers on the greenhouse benches. Now, unlike some growers, we always washed, sterilized and reused all these plastic containers until they were well beyond use. Even when one or two of the cells of the thin six-pack material would break or degrade, I saved the units and would nest two of them with broken cells overlapping complete ones until the bitter end.

Yes, I know there are other planting containers... peat pots and others made from cow pies and such. Their main drawback, the higher price, took them out of contention especially when coupled with their designed single use.

This year I decided to invest in the infrastructure to begin moving away from all that -- to avoid the whole container issue almost entirely -- by planting in soil blocks. I suspect that any plants I sell will need to have their 2" or 4" block placed into a pot for the customer, though I am hoping to introduce the more environmentally aware customers to the old-fashioned way of buying transplants. Back before the advent of the plastic pot, greenhouse growers used wooden boxes to grow their transplants and would carefully remove the plants you had selected from the box with trowel and fingers, and wrap them carefully in newspaper for their trip home. If the larger soil blocks hold up as well as the smaller ones that were just "potted up" yesterday, I should be able to do this easily, or even to plop the selected plant blocks down into recycled cardboard "flats" in which stores get a variety of beverages.

But back to the blocks...

The soil block making tools can be manufactured at home; there are a variety of plans on the Internet for such contraptions. I chose, however, to buy metal ones from Johnny's Selected Seeds. I got three sizes; the mini block maker for starting most seeds (3/4" blocks) and the 2" and 4" sizes most often used for "potting up" as the seedlings grow but also useful for the larger seeds of squash, melons, etc. I did a lot of reading on the Internet, as well as talking to folks who had used the block makers, to try to learn the ins and outs. I learned that not all soil mixes work and that there was no consensus on whether the ProMix that I have on hand was good. I also learned that the wetness of the soil used to make the blocks is very important.

The soil needs to be SOGGY! This is bound to be counter-intuitive for anyone who has experience planting in flats or other pots. Notice not only drips, but an actual stream of water falling from the handful of potting mix as I squeeze it. If water does not squish out the top of the block maker as you push it down into the potting mix, the blocks will fall apart.

Next you load the blocker. I have talked to people who use a plastering trowel to scoop up the mix and force it into the block maker. I chose to put my tub of potting soil on a chair and to push my tool into the mix, repeatedly and with force. Having the work surface down low makes it easier to put more "oomph" into it. Squish as much potting mix into your block maker as you can; you cannot overload it!

Make sure you scrape the excess off the bottom of the block maker. Some folks run it along the edge of their soil tub. I scrape it with my hand.

Then place the blocker into the container that will hold your blocks. I still have some plastic flats, so I am using them at present. Push down the block maker, squeeze the handle to release the blocks and lift. Sometimes a very slight shake is necessary to release the blocks from the tool.

Voila! you have a set of soil blocks! Continue until your container is filled. You can put each set of blocks close to the previous ones; the blocks do not need much space at all between them.

One of the benefits, for me, to using the mini blocks is that they prevent me from planting my seeds too close together! I have a bad habit, when seeding flats, to over plant. The seedlings emerge too close together, get leggy. Transplanting them into six-packs is hard on me and on the plants, too.

There is a trick to getting just one, or at most two seeds into each tiny block. I will admit that this process takes a bit of patience, but it also makes your seed go much farther! All you need is something to hold a bit of water and a toothpick.

Just a bit of wet and the toothpick will pick up a tiny individual seed.

Usually touching the seed to the block will leave it there. At most, you will need to brush or rotate the toothpick a bit to leave the seed behind. The hardest part, when doing tiny dark seeds, can be remembering where you are in the sea of blocks!

I cover the seeded tray with a sheet of saran wrap to keep them moist until the seedlings begin to emerge. You will need to be very vigilant in keeping the blocks moist! This may be the biggest challenge to using soil blocks. Because they are surrounded by air on 5 of their 6 sides, they dry out very quickly. You will need a gentle mist to water them, or your sink spray attachment just barely turned on. Until the seedlings get some roots to help keep the blocks together, it is easy to damage the block structure by too hard a spray.

These are the 2" blocks, which were made with 3/4" holes in the center to accommodate the tiny blocks. These herb seedlings have been potted up to the larger size blocks and will grow here for some time. Depending on how they grow and where they will end up, these blocks may go directly into our garden, or onto the sales tables at our markets, or they may get potted up once again to be sold as herbs in 4" pots later in the season.