Now’s the time to divide perennials, if you haven’t done so in the last few years. If your perennials are showing smaller blossoms or dying off in the center, then dig them up, clip the crowns, and spread them around after cutting out dead and crowded roots. They like room for their roots to grow. Keep the cutting moist until you’ve put them back in the soil. Do this early; don’t wait until there’s a chance that your soil will start to freeze. If there’s a question, wait until early spring, just as the ground thaws and the plants begin to show signs of life. Either way, be sure to add some compost to the soil where they’re planted.
September is also the time to plant bulbs for spring crocus, daffodils, and tulips. Wait until the nights have become cool. The ideal soil temperature for planting bulbs is around 60 degrees. For tight, impressive displays, plant bulbs in a circle. Or just place them where ever you have room and they’ll have enough sunlight to thrive. Bulbs like well-drained soil so be sure to stick in some compost. Don’t wait to plant them; they should have at least a month to adapt to their new homes before the soil freezes. This is also a good time to fertilize established bulb beds. Give your bulbs a natural source of phosphorous as well as a balanced organic fertilizer. Don’t wait until spring. Fertilizing in the spring will help little when your flowers are already on their way.
September is also a good time to plant grass seed, lay sod and dig in new trees (bonus: buying trees in the fall will give you an idea of what their fall foliage will look like). But will leave that for another time. You’ve got enough to do getting ready for spring flowers!