Straw bale gardening is a great no dig garden method and a raised bed garden all at the same time. The number of bales that you use will depend upon the size you want the garden to be. You could grow a few cherry tomatoes and some basil in one bale.
Be sure to place the bales where you want them to stay, because, they are not easy to move. The bale will last for one or two seasons and makes ideal mulch or can be composted when its life as a garden is finished.
You can grow, for example, tomatoes, potatoes, squash,
greens, peppers, gourds and flowers in straw bales. The peppers and tomatoes
could be staked if needed.
I grew potatoes for two seasons this way and then used the
straw to begin a new no dig garden bed.
I suggest, when you have selected the spot where the straw
bale raised garden will go, you place the bales on their sides. Next water the
bales over a seven day period, making sure that they are wet right through.
Add between three and five inches of compost to the bale tops and you are ready to plant. Salad greens will do well in this garden and will begin producing quite rapidly if they are placed where they get the sun they need to grow.
Alternatively to adding soil to the top of the bale, you
could cut a few holes, depending upon what you are planting, in the bale, add
compost and plant.
It is important to use straw bales rather than hay as hay
has seeds in it, and you will get a crop that you are not looking for and one
that will compete with the plants you want. Wheat straw is readily available in
many places and does very well as a garden bed.