Ian Robertson, Ltd.
Horticultural Tips
September Tips
q Do not prune or fertilize trees or shrubs this month. You want to avoid forcing tender new growth which can be injured by hard freezes.
q Be very careful when mowing or using a string trimmer around trees - damaged bark can allow entry for borers. This is particularly a problem for dogwood, flowering peach, flowering cherry and flowering plum.
q Mulch trees, shrubs and perennial beds to conserve soil moisture and help protect plant roots from freezing temperatures. Remember to keep the mulch away from stems of plants to prevent rot and away from certain perennials, such as Iris and Chrysanthemums, which also tend to rot if heavily mulched.
q Plant peonies and Bearded Iris this month.
q Continue to deadhead and fertilize annuals and perennials. They will continue to bloom until frost.
q Plant containers with fall annuals including chrysanthemums, pansies, sweet alyssum, snapdragons, ornamental cabbage and kale, and calendula.
q Fertilize roses lightly with a liquid fertilizer every six to eight weeks. It is preferable to use an organic fertilizer so that the soil microbes are being fed as well.
q Repot any house plants that may need it, and inspect for signs of insects before bringing them in for the winter.