You started conditioning your bales, but were interrupted by Mother Nature. Snow, rain, cold, whatever has thrown a twist in your progress and you are now concerned that the bales will not be ready to plant on time. Relax, and just pick up wherever you left off or were interrupted, and continue the process. One tip for speeding up the process if you are concerned that the bales are not conditioning quickly enough for your planting schedule, is to cover the bales with some black plastic sheeting. This will help adsorb heat energy from the sun and hold in the heat promoting the growth of bacteria in the bales. This isn’t required but can be helpful if you are on a strict schedule and need to plant on a particular date.
It is true that if the air temperature is cooler, the bacteria will not grow as quickly. This is why we refrigerate our leftovers from dinner, or put stuff we want to preserve in the freezer. When bacteria are cooled or frozen they will not reproduce as quickly and their effective rate of decomposition of any substrate will slow dramatically. If the bales warm up to even a slightly higher than air temperature level, this means the bacteria are growing inside. Bacteria reproduce by expanding to a certain size and then splitting. During this magical splitting process, the cell will shake and vibrate and create friction, which raises the temperature inside the bales. If the air temperature outside is 40 degrees but the temperature inside your bales is 45 degrees, this is a great sign of bacteria development. If the air temperature is 75 then the inside of your bales may be 130 degrees or hotter. The differential in temperature will increase as the air temperature increases. Don’t expect too much if your bales are in the “refrigerator” or the “freezer” outside. When the days get warmer the bacteria will grow quickly. Plan to plant after you have been conditioning the bales for 12 days (when the temp is over 45 degrees). If you get a few colder days, just add a couple more days to the conditioning period, or cover with black plastic. A sunny day will really get things cooking under that plastic. It is NOT necessary for your bales to ever get HOT. Sometimes they don’t get so hot, but they will always get warm. If you measure the temp every day and the temp never goes above 80 or 90 degrees, don’t worry, they will be fine. If you put your hand into the bales and they feel cold, don’t worry, if you followed the conditioning recipe then the bales are ready to plant after 12 days (18 days for the organic treatment), so plant or seed right away. Don’t worry if it seems like the bales still look the same, they will not have changed much in appearance, but the bacteria will have grown and colonized much of the bale by then, so it is time to plant.
One of the biggest misconceptions about the entire concept of Straw Bale Gardening, is that we plant and grow vegetables in straw. Let me explain what is really happening. We do start with a straw bale but we don’t plant anything in the bale for several weeks, until we first “condition” the bale. This conditioning process builds up the bacteria level inside the bale until the bacteria completely colonize the bale. The bacteria begin to consume, and digest the straw, breaking down the cell walls, and releasing the molecules inside those stalks inside the bale, essentially creating “soil.” All productive soil that covers the surface of the earth is made from decomposed organic material. Whatever has ever been alive, eventually dies and is decomposed and ultimately becomes soil, which is then the source of nutrients for the roots of new plants to adsorb and grow. When Mother Nature grew the oats or wheat, it took a variety of specific nutrient molecules to create the cells of each plant. Nitrogen, phosphorus and potassium are the three key nutrients, the basic building blocks of most plant life on earth, then there are a large number of micro nutrients, those molecules that are required for cell construction, but only needed in very trace amounts. These trace elements might include iron, calcium, zinc, etc. The cells expand and divide and expand and divide, growing an oat or wheat stalk and seeds. The seeds are harvested, but the stalks are baled up and now arrive in our gardens. It is now up to Mother Nature to help us decompose these cells that she constructed (grew) last summer using soil, and deconstruct them back into soil once again. This happens naturally, but much more slowly than we need it to happen for our purposes. We can help speed up this deconstruction process by feeding the naturally occurring bacteria in the bales, in order to speed up the process. Mother Nature has a tool box of decomposers that she uses for this intricate job of deconstructing every living thing on earth. She uses insects, worms, fungi, mold and the real heavy lifter, bacteria, too perform this amazing task. These little workers get busy digesting our straw bales, and very quickly break down the cells of the wheat, oats, barley, rice, grass, alfalfa or whatever substrate we have in each tightly bound bale. The brand new soil created by this process contains all of the micro nutrients and trace elements as well as the Nitrogen, Phosphorus and Potassium that were contained in the stalks. So when someone sees a bale of straw in your garden and says “you can’t grow plants in straw”, you’ll need to explain that they are exactly correct but the bales are not really straw, they are simply quickly decomposing sources of virgin soil.