Thursday, March 20, 2008
Boiling and baking
Indoor vegetable gardening is very much about baking and boiling, not the vegetables themselves but the soil and the water. You may have noticed that I sometimes writes that I'm about to sterilise soil.
As to the soil it's because I recycle it, and will use the same lumps over and over again. To kill all pests, fungus and illnesses left from last time that may harm the plant I sterilise the soil in between uses. My method is quite simple; I put a pan of soil into a heated oven (200¤C/392¤F) and leave it there for twenty minutes. When I bring it out I pour the soil into a big terracotta pot for cooling. Most often I have so much soil I use an extra pan and have to find some extra big pots for the heated stuff. Changing pans and running for extras do give you your daily exercise.
Sterilised soil is completely dead, ie. it lacks germs and fungus that are good for the plants. In general I mix in some unused, unsterilised soil to add them again, but I'm not sure how well this works. Perhaps I should take a look on the specialty shelves for plant protection and see if they have cultures on a bottle (wouldn't be surprised). In the future my plan is to add vermicompost instead, it's not only nutricious but contains those friendly creatures as well.
Water is boiled for another reason. Sweden and Uppsala have very good tap water, you're able to drink it directly from the tap. But in Uppsala it also contains calcium. The calcium accumulates in the pots, forming uggly crusts that are harmful to the plants. To clean the water the easiest method is to give it a quick boil, which releases the calcium, and then let it cool. Then you can see small dustroses on the bottom of the cauldron as well as some flaky dust floating around on the surface – that's calcium. It forms a dustlayer on the sides of the cauldron as well, but you can't see it before you've emptied it.
To save time and energy I boil ten litres (2,6 gallons) of water at the time, and then collect it in a twentyfive litre (6.6 gallon) plastic can. As you may guess I just don't tilt the pot and pour the water directly into it. The weight is not so much of a problem as the fact that this stirs the calcium. Instead I use a siphon; I put the pot on a high place and the can lower, then I take a small hose and put one en into the pot a bit above its bottom. The other end is held lower then the pot and then I suck a bit on it which makes the water flow through the hose, and it'll continue to flow as long as that end is place lower than the highest water surface. Don't forget the cloth if you try this; it's easy to splash some water around when you're trying to get the hose into the can as fast as possible.
You could leave it like this, but I prefer to watch over the process to see that no calcium is sucked into the tube. This means I stand with the hose in hand those five to ten minutes it takes to collect the clear water out of the pot (to avoid being bored I read a book). When there are about two litres (half a gallon) left I stop siphoning and use the rest of the water for cleaning the cauldron – it takes on a milky white colour when I sweep the dish brush around.