Jean Kuehn, Extension Master Gardener in Anoka County
As we put our gardens to bed and prepare them for the long cold winter, many of us mourn the end of another gardening season. It really is not an end, just a different phase of being a gardener. Even as we begin the process of cleaning up and cutting back, we should be planning which plants need to be moved now or next spring, which ones will need to be divided, which need more or less sun to improve their health, and which we may remove completely or add next season. A notepad or journal may be of help to record thoughts. In reality, gardens are never really "finished", they are always a work in progress.
The turtleheads are still a gorgeous pink, the bottle gentian are a true blue, and asters add color too. What great fall plants. The iris, lilies, monarda, malva, peonies, and hosta can all be trimmed. However, do not trim shrub roses. If they are trimmed now, the new growth likely would not be winter hardy. Besides the rose hips are already turning red and will look rather charming until a hungry bird finds them. Before you put the tools away, clean and disinfect them to prevent spreading problems from one plant to the next.
Trees continue to need water until the weather is seriously cold. Trees take decades to grow and are worth the effort, so keep them well water going into the winter. Did you know that fall is the best time to plant new trees? They can be successfully planted until the ground freezes.
Fall is also the best time to fertilize grass. Fall fertilizing encourages root growth which strengthens the plant, while spring fertilizing tends to encourages top growth and the need to mow frequently. Also, lowering the mower blade when cutting in the fall is good for the grass, plus it makes it easier to rake up the leaves.
To cover or not to cover the garden – is that the question? The garden should be covered after it has gotten fairly cold. The worst damage to our perennials is done by short periods of warm weather in Jan, Feb March. The warmth fools the plants into coming out of dormancy and start growing and then the temperature plummets and the plants freeze. A good cover of leaves or straw will prevent sunlight and heat from penetrating the soil and keep the plants cool until real spring arrives. Lightly rake off the cover as the spring weather warms so the plants don't cook.
Fall cleanup may be the end of one gardening season, but it is also the start of the next.