What steps should gardeners take to clean up their gardens in the fall?

The clean-up process is very important for the whole garden. You’ll want to leave as few of the dead leaves that have fallen off this year’s growth as possible, especially if they were diseased leaves. As an example, black spots on roses are a fungus. Other plants also have fungi. If you live in a cold climate, the whole garden will become dormant, with the exception of a few evergreens, so you want to clean up around everything to protect from the over-wintering fungi.

For summer perennials such as sage or phlox, cut down all but about four to five inches of the dead foliage and put it on your compost heap. Clean up vegetable and annual beds by pulling out the plants that aren’t perennials. A plant such as rhubarb, for example, would stay. Also, take up items such as beanpoles, because they can also harbor fungi

What needs to be done with bulbs?

Serious gardeners should have some sort of gardening encyclopedia to give them the best method for resetting various types of plants. Plants that really like to be separated and reset in the fall are irises, narcissus and related spring-blooming bulbs. Plan to dig those up about every third year and reset them, because they become so dense that none can really grow big enough to bloom nicely and the bloom declines. When you begin to see the spring blossoms decline in vigor or the plants are not blooming at all, they need to be reset.

For irises, take out the old, elongated rhizomes (the old roots), remove the new plant from the old root, throw out the old root and reset the new plant. With bulbs, you also have to be willing to throw out things, such as little daffodils and little narcissus that are crowding out your bigger good plants and reset the larger ones in a hole with some bone meal added to the soil.

Most other plants like to be reset in the spring. You can reset daylilies in the fall, but I find they do better if you reset them in early spring.

How should you mulch plants?

The very best winter mulch consists of leaves chopped up with your lawn mower. Leaves generally will mat down if you just put them down without being chopped up. For perennial borders, place chopped leaves over the entire border. Under the snow, the leaves begin to rot, so you are constantly improving the soil.

For shrubs, after cleaning up the dead leaves place compost or some form of mulch around them for winter. Spread the chopped leaves several inches thick around the base of the shrubbery. If you don’t have enough leaves and you can’t scrounge any from your neighbors, you should use compost or wood chips as mulch. Never use hay or straw, because mice will set up housekeeping in the hay or straw during the winter and chew on the stems of the shrubbery. Also, all shrubbery should be pruned in the early spring, not in the fall. You have to wait until some shrubs have bloomed before pruning them. The same is true of some of the flowering fruit trees.

You can mulch heather and heath with pine needles. I protect the whole root system by making a very thick collar around the plant with three to four inches of pine needles.

How do you prepare roses for winter?

With roses, you really shouldn’t do much of anything until they are dormant — after a really hard frost. When they are dormant, clean up the leaves and spray the plant and the ground around it with a mild solution of dormant oil (available at garden centers) to control fungi. Don’t spray Rugosa roses with anything, because they’ll lose all their leaves.

For big, tall roses, I suggest a step that comes as a surprise to a lot of people. When the roses are dormant and have lost most of their leaves, use black plastic electrician’s tape and encircle the canes to keep them from whipping in the winter wind. That prevents the roots from being loosened up by the action of the wind. If rose roots are disturbed and wind begins to get in, it dries out the roots. At best it distresses them and can kill them.

The last step is to sprinkle a handful of an organic material called Sulpomag (available at garden centers) about four inches out from the crown of the plant. Then, place a shovelful of compost or composted manure right on the crown of the plant, the bulbous part right at the soil line where all the canes come together.

Tender rose plants grown in zone four or zone three must be cut back and covered with a rose cone. (I normally advise people to buy plants for their climate zone, because they require less work.)

For climbing roses, I leave them where they are on the trellis or post, encircle them with burlap and tie the burlap down.

In cold climates, don’t do any pruning whatsoever after Sept. 1.

What other garden chores should be done in the fall?

If you are planning new beds, I recommend digging them in the fall. Dig and prepare them completely or at least take up the grass and throw it away. Get the bed completely turned over and add some amendments, such as some compost, manure or peat moss.

Consider using the following trick to create wonderful beds — although it may take two or three seasons before it’s appropriate to do a lot of planting in the new bed. First, stir up the turf or remove it completely and lay newspapers all over the area. Then, put about two inches of manure, covered by about six inches of mulch, over the newspaper and let it sit. The snow cover makes everything damp and makes the components rot. I created such a bed three years ago. I planted some things in it last summer and planted some hardy geraniums in it this summer. In the year or two before it’s completely ready, you can plant pansies or petunias to hide the fact that the bed is maturing.

Fall also is a good time to plan changes to your garden. I keep a notebook of my garden and make a list of things I want to move in the spring. During winter, particularly in the cold north, you can peruse garden books and magazines to decide what you want to do in the spring, such as making a new bed or a new garden structure, or putting in a pond.

Good gardening reads

“Perennials for Every Purpose: Choose the Right Plants for Your Conditions, Your Garden, and Your Taste,” by Larry Hodgson; hardcover – 502 pages
1st edition (February 2000) Rodale Press;
ISBN: 0875968236

“The Natural Garden” by Kenneth Druse;
Clarkson Potter; hardcover - 296 pages (March 1989), ISBN: 0517550466
“Lois Hole’s Favorite Trees and Shrubs”
by Lois Hole, Jill Fallis and Akemi Matsubuchi photographer; paperback (February 1997)
Lone Pine Publishing; ISBN: 1551050811

“Growing Roses in Cold Climates” by Jerry Olson, John Whitman and Paulette Rickard; hardcover – 272 pages (January 1999) NTC/Contemporary Publishing;
ISBN: 0809229412

“The Harrowsmith Perennial Garden” by Patrick Lima, Marta Scythes illustrator;
paperback – 160 pages (December 1987) Camden House Pub;
ISBN: 0920656749

Shades of fall

Add color to your fall garden with these plants:

• Asters
• Calendula
• Heathers and heaths
• Late-blooming daylilies
• Marigolds
• Mums
• Rugosa roses
• Sedum
• Zinnias