Plants Rest Easier on Raised Beds
One idea that I have picked up from both reading and from other gardeners is the idea of using raised beds to grow vegetable crops. If you read gardening books, many will list a huge number of advantages of using raised beds. In my post here, I am going to give you my personal experience with raised beds and what I have found their primary advantages to be for me.
First of all, my 2 acres of land is pretty much 100% dense clay. In other words, the soil is pretty horrible for vegetable gardening. So one big advantage of using a raised bed is that the bed frame gives me a well-defined and relatively small area to dig out and amend with better soil. I dig out all of the clay inside the frame and replace it with a mixture of primarily sand & loam (although I will usually add back a little of the original clay too). The little raised bed frame that I create and place on the ground gives me a small, targeted area to dig out and replace with a mixture of the soil types that I want to use. The frame also gives a very clearly delineated area in which your crops will be planted, clearly segregated from the surrounding ground.
Secondly, Northern Indiana is one of the many regions of the US that experiences weather extremes from season to season. The problem that we often face here in the spring is that we frequently have sequential days of torrential rains in March, April and May. Seeds or seedlings that are freshly planted at ground level will frequently be washed away or sitting in standing water for days in the spring here. A raised bed allows for greatly enhanced water drainage compared to ground level for the fragile seeds and seedlings. Otherwise, many seasons would result in the loss of large percentages of seeds and seedlings in spring due to suffocation of the root cells.
Third, the frame itself can be used to attach other gardening accessories to the bed. The most common accessory that I use at the current time (and that you can see in the photo above) is sheets of black plastic mulch. I have a tendency to grow a lot of tomatoes and cucumbers, and I like to get as early a jump on the growing season as I can. But Northern Indiana has a long and brutal winter. One of the things that I can do to raise the soil temperature of my garden beds quickly after winter is to cover them with black plastic sheets in the early spring. The black plastic absorbs visible light from every wavelength in the visible electromagnetic spectrum and re-radiates that energy as infrared (heat) to the soil. This gets the soil temperature of the beds up much more quickly than uncovered soil. In addition, of course, the black plastic sheet completely eliminates the terrible task of constant weeding during the growing season. The plastic sheets can be stapled to the frames to secure them (in my case the frames are all wood or PVC (fake wood)). I will also normally try to mound the soil in each bed so that the plastic sheeting will fit tightly over the bed and so that rain water will drain off the sheeting and not pool on it for any great length of time. In addition to black plastic sheeting, I plan to try using mini-greenhouses and hoop houses in the very near future and the frame of the raised bed will provide a good attachment point for such a device.