We do a soil drench for plants and schrubs. We fertilize every shrub right down to plants and flowers. We evaluate how much each plant needs. Some shrubs may need more feeding than others. Some need none.
Cactus: We often educate customers to leave them alone. It is important to give them no water, no feeding and very little attention. It is not uncommon to over-water cactus which need no water at all. Often we tell people to remove irrigation to their cactus.