The problem with planting in that flower bed is that you don't know what type of soil is in it, or what has been added to the soil before. It is too late for the larger plant, but you can still change the soil on the smaller one. Go with a good mix of healthy ingredients and make a nice, rich, organic growing medium for your plants. Try mixing some plain potting soil, peat(coconut husks are even better), vermiculite, wormcastings, bat guano, bird guano, fish emulsion, and some maure. You can even add a bit of volcanic soil if you can find some to add a lot of trace minerals. At most gardening stores you can also buy premixed organic soil, but most likely you will still need to add some perilite, vermiculite, and peat to help loosen it up and aerate it.