We consider the problem of constructing Gardner's deformations for the N =2 supersymmetric a = 4-Korteweg-de Vries ͑SKdV͒ equation; such deformations yield recurrence relations between the super-Hamiltonians of the hierarchy. We prove the nonexistence of supersymmetry-invariant deformations that retract to Gardner's formulas for the Korteweg-de Vries ͑KdV͒ with equation under the component reduction. At the same time, we propose a two-step scheme for the recursive production of the integrals of motion for the N =2, a = 4-SKdV. First, we find a new Gardner's deformation of the Kaup-Boussinesq equation, which is contained in the bosonic limit of the superhierarchy. This yields the recurrence relation between the Hamiltonians of the limit, whence we determine the bosonic super-Hamiltonians of the full N =2, a = 4-SKdV hierarchy. Our method is applicable toward the solution of Gardner's deformation problems for other supersymmetric KdV-type systems.