The only thing that will encourage more grow in the bare areas is more light. Trim away all the crispy dry, dead twigs. On the top, it is likely that all the dead belongs to one branch, if you follow the twigs down into the shrub. If this is the case, then remove that whole branch. Extra fertilizer will accelerate the normally slow process of regrowth in those areas, but will also make the entire shrub grow bigger faster. I'm not sure you want to do that in such a confined area. It is too late in the season for fertilizing your evergreen yew if it were growing in the Minnesota where I am. That might still be the recommendation for Missouri, too. I don't know. Fertilizing in spring is good no matter where you live. |
It may be spider mites. Do you notice webs in the bare spots? You can use insecticide sprays to control the pests or predator species. Lady beetles and parasitic wasps are predators of spider mites. I have also heard of treating the bushes with a peppermint oil solution, but not sure of its efficacy? |