If there are trees that are shading the area, remove some branches to get more sun.  Probably, in your case, you need to beef up the soil with more organic matter (like compost)  and nutrients.  For nutrients I’d suggest turning in some Bio-Tone plant food as soon as the soil warms up.  Bio-Tone is a combination of high quality organic nutrients as well as a host of soil microbes and beneficial fungi to supercharge you depleted soil.  More on Bio-Tone HERE.