Like water, seed starting soil is another matter taken for granted. However, there are considerations with soil which may impact the success of your seed starting adventure. Some of those considerations are density, ph, fungi and insects.
If soil is too dense as is typical of varieties of clay new roots may be squeezed to death, deprived of moisture or any other number of disasters. Common soil and sand are better than nothing provided they are mixed at ratios that drain well. Some add artifical mixers such as pearlite to loosen up the soil.
Each plant has differing ph requirements. While a plant may grow in soil an imperfect ph balance it will not flourish. To determine soil ph there are many soil testing kits available. Likewise, thre are simple methods of adjusting soil ph once you have simple, yet affordable methods of testing. This will be discussed in greater detail in future posts.
Soil is a notorious lair for fungi, molds that will criple sprouts and enen consume them. Not a happy sight. In the same way, insects don't seem to care where they make their homes while they are particularly good as hiding almost anywhere. For seed starting purposes the most common way of preparing soil for seed starting is to bake it in your oven. Two hundred fifty degrees for one hour will take care of these invaders and also kill weed seeds.
When I am making my own seed starting mix I generally dig half a wheelbarrel of dirt and grate it through a simple wire screen. It is just a 12" X 12" wood frame with 1/4 inch screen that is stapled on the bottom of the frame. As I grate I remove all the small stones, grass and weeds. This gives me enough dirt to fill four rectangle baking pans which I put in the oven and bake. Yes, it smells like dirt, but the odor disapates well. Afterward, I mix in filler. Sometimes I mix in pearlite, sometimes ground up straw and fine sand. It really depends upon what I have on hand at the time.
Next I check the soil ph with a testing kit. If the ph is too high I add in fine peat moss although there are many other methods to lower ph. If the ph is too low, I add in a small quantity of firewood ashes, although again, there are many other methods to raise soil ph.
There are many manufactured seed starting mixes and I prefer to use them. However, if I am germinating a fragile species of seed, or if the mix looks suspect, I will go ahead and bake the manufactured soil just to make sure. For those with microscopes it is possible to eliminate the necessity to bake by examining the soil for fungi and evidence of insects.
When starting seeds indoors there is always something to look forward to. If you have ever started seeds on your own then you know how addicting a hobby this may become.