How to Winterize a Garden

Steps

1. 1

   Mark your calendar

   Start winterizing two to four weeks before the average first frost date in your area. In much of the United States, that date falls between late September and early November.

2. Find your first-frost date first: every step below is timed from it. This date can vary by two months or more across the country. Look yours up through NOAA or your local agricultural extension office. Two to four weeks before that date, drain hoses and clean up beds. Just after the first frost turns foliage black, cut back perennials and lift tender bulbs. Wait for the first hard freeze to lay down mulch. A hard freeze is when the air drops to about 28°F, which is -2°C, and stays there for several hours. Do not mulch before then. Early mulch traps warmth and invites rodents to nest.
3. 2

   Shut off water systems

   Drain your garden hoses before the first hard freeze. Shut off your irrigation system too. Water left inside can freeze and expand. That cracks pipes, hoses, and fittings.

4. Water evergreens before it's too late: give evergreens and newly planted trees a deep watering before the ground freezes. Evergreens keep losing moisture all winter. They cannot draw more water from frozen soil. Do this around the same time you drain your hoses, while water is still easy to use.
5. 3

   Clean up garden beds

   Wait until the leaves and stems have died back. Then put your garden gloves on and clear your beds. Dead stems and weeds can scratch, and some plants irritate skin. Remove annuals that have finished, weeds, and any dead or diseased plant material. Annuals are plants that live for only one season. Old plant debris can shelter pests and disease through winter. Healthy stems and fallen leaves can stay if you plan to leave some plants standing, as the next step explains.

6. 4

   Throw away diseased plants

   Put any diseased plant material in the trash. Do not add it to your compost pile. This is because most home compost piles never get hot enough to kill the pathogens. Pathogens are the germs that cause plant disease.

7. 5

   Trim back perennials

   Perennials are plants that come back year after year. Many gardeners cut them back to a few inches above the soil once the leaves have died back. It is fine to leave some standing. This is especially true for plants with seed heads, such as coneflowers and ornamental grasses. They feed birds and shelter helpful insects through winter.

8. 6

   Lift and store tender bulbs

   Tender bulbs cannot survive a cold winter in the ground. Dahlias, cannas, and gladiolus are tender bulbs. Dig them up after the first frost turns their leaves black. Let them air-dry for a few days. Then pack them in a container that lets air through, with peat moss or a similar material. Store them somewhere cool and dark, around 40 to 50 degrees Fahrenheit. That is 4 to 10 degrees Celsius.

9. 7

   Lay down protective mulch

   Mulch is a loose layer of material spread over the soil. Wait for the first hard freeze. Then spread a layer of organic mulch two to four inches deep around your plants. Straw, shredded leaves, or wood chips all work well. Keep the mulch a few inches away from stems and trunks, or they may rot.

10. Don't forget pots: potted plants freeze from every side. They act like the same plant growing one or two zones colder. A zone tells you how cold winters get in an area. Empty your terracotta or ceramic pots and store them, because wet soil cracks them as it freezes. For pots that still have plants in them, move planted containers against a sheltered wall or into an unheated garage or shed.
11. 8

    Clean and store your tools

    Clean your garden tools at the end of the season. Rub off any rust with a wire brush or a cloth. Wipe a light coat of mineral oil onto the metal parts. Do not use linseed oil or another drying oil. When you are done, lay the oily rag flat outdoors to dry, or spread it on concrete. Never ball it up or bin it damp. A crumpled rag holding drying oil can heat itself enough to catch fire hours later. Then store the tools in a dry place.

12. A few mistakes worth avoiding: do not prune flowering shrubs in fall. This includes lilac, forsythia, and old-wood hydrangeas such as bigleaf and oakleaf. These shrubs form next spring's buds over the summer. A fall cut removes the flowers. Step 5 is about perennials, not shrubs. Also, disconnect hoses from the outdoor tap instead of leaving them attached. Trapped water can split the pipe behind the wall. Some irrigation systems need a compressed-air blowout rather than a simple drain. That is a job to hire an irrigation professional for. The wrong pressure can damage fittings or injure someone.