The Imperial brands are not to be planted in your area in the spring unless your in the northern part of the panhandle.
You will need to do a soil sample and lime at a rate of 2-3x' s the amount suggested. This will allow the lime to work into the soil and bring the pH value up in the area under neath the planting area. Alfalfa blends should root deep, up to 15-20 ft in a few years. This makes them more adaptable to the more well drained soils. You may also want to lime, fertilize and plant the area with a more forgiving annual in the spring and re-plant the area with the alfalfa blend in the fall. The cooler late summer/early fall months will allow the plant to root. Rooting is everything... Do not be in a hurry to fail...