What to do now
Mildest step first.
- In the vegetable beds, pull plants that had blight, leaf spots or squash bugs and put them in the trash; compost the healthy ones and leave flower stems standing.
- Cover bare soil with a few inches of shredded leaves or straw (not hay), or sow winter rye if it isn't too late where you live.
- If your last soil test was 3 or more years ago, take a sample now so any lime has months to work before spring.
- Scrape, sharpen and oil your tools, and drain the hoses before they freeze.
Pull the problem plants
Start with the plants that had problems. Iowa State notes that removing and destroying diseased plant debris reduces the severity of many diseases and also removes winter shelter for some insects; early blight and Septoria leaf spot on tomatoes, for example, survive the winter on infected debris. University of Wisconsin's Milwaukee County office suggests putting late blight-infected tomato fruit and potato tubers in the trash, and bagging heavily infested tomato, potato and pumpkin plants. Squash bugs spend the winter as adults under debris near last year's plantings, so Colorado State suggests clearing mulch and debris from those beds. Take up black plastic mulch too, which Milwaukee notes can shelter pests.
Compost or trash?
Healthy plants can go in the compost, and University of Maryland's Maryland Grows blog suggests shredding them first. Diseased plants are another matter. Maryland says they generally shouldn't go into a home pile, since only thorough hot composting kills some fungal diseases, and Milwaukee gives 120 to 170°F as the core temperature a pile needs to kill weeds, insect eggs and pathogens. UC Master Gardeners say to put diseased material in the trash and not compost it. If your pile doesn't get that hot, the trash or a municipal compost program is the safer place for blighted plants.
Leave the flower stems
Leaving plants standing helps bees, beneficial insects and birds, and extension services mostly reconcile that with the cleanup advice by place. Asked whether to leave plants for overwintering insects, Maryland Grows answers yes, but not in the vegetable garden, because a bed of annual vegetables that gets replanted each year is different from a border of perennial flowers. Iowa State and Penn State Master Gardeners suggest leaving most perennial flower stalks and seed heads through winter: many native bees overwinter in hollow stems, and the seeds feed birds. When you cut them back in spring, Illinois suggests leaving 12 to 18 inches of stem for bees that nest in them, and waiting until nights stay above 50°F.
Cover the soil
Then cover what's left bare. Maryland Grows calls covering the soil the final step: shredded or whole leaves work well, and straw is better than hay, which carries more grass seed. Penn State Master Gardeners suggest spreading fallen leaves 2 to 3 inches deep on the vegetable garden, and UC suggests mulching most uncovered soil 4 to 6 inches deep. Perennial crops get their winter mulch later, once the soil has cooled. Iowa State suggests about 4 inches over perennial crowns after the ground freezes, since mulching too early can delay dormancy.
A cover crop, if there's time
A cover crop is a living mulch, but it needs time to get established. University of Maryland's window for fall cover crops runs from mid-August to mid-October, with winter rye the one that can go in latest. Penn State says rye can be sown as late as early November in Pennsylvania because it still germinates at about 35°F; its rye guide adds that very late sowings mostly pay off in spring. If you've missed the window, Oregon State suggests mulching right away instead, with leaves, compost or even cardboard.
Soil test and manure
Fall is a good time for a soil test. University of Maryland notes that lime and compost added in fall have time to work before spring, and UNH explains that lime works slowly, so fall gives it time to react, while fertilizer is better added in spring. Maryland suggests taking 10 to 12 small samples, 6 to 8 inches deep, mixing them in a clean bucket, and testing a vegetable garden every 3 years. Fall is also the time for uncomposed manure. Wisconsin explains that USDA organic rules call for at least 120 days between spreading it and harvesting crops that touch the soil, and 90 days for crops that don't, so manure spread now fits that rule for next year's crops. Its author's own research found that even 90 to 110 days may not be enough with fresh cow manure, and pet waste should not be used at all.
Tools and notes
Last, the tools. Iowa State suggests scraping off soil with a wire brush or putty knife, sharpening hoes, shovels and spades, wiping metal with an oily rag, rubbing rough wooden handles with linseed oil, draining hoses and storing everything somewhere dry. Disinfect pruners that touched diseased plants with 70% rubbing alcohol, or soak them for 10 minutes in a 1-to-9 bleach solution and rinse. UC suggests emptying and cleaning pots and bringing clay pots inside. While the season is fresh in your mind, write down what grew where; Clemson suggests keeping notes for crop rotation, so the same crop goes back in a bed no more than once every three years.
- TomatoThe warm-season anchor of the summer garden.
- PotatoA tuber grown from seed potato, not seed — and the crop most likely to surprise a first-year gardener with its yield.
- ZucchiniThe summer squash that turns a garden into a produce stand — if you can keep the vine borers away.
- GarlicThe crop you plant in fall and harvest next summer — the longest timeline in the vegetable garden.
- Winter RyeThe hardiest cereal cover crop — a weed suppressor that survives winters that kill wheat.
- Which cover crop should I plant in my garden?Choose by goal and timing: crimson clover, hairy vetch or field pea for nitrogen; winter rye or oats for organic matter; tillage radish for hard soil; buckwheat for a summer gap. Sow most 6–8 weeks before first fall frost.
- When is the best time to add compost to the garden?Fall is a good time to add compost to garden beds — it has all winter to incorporate and break down further, and beds are ready to plant without delay in spring.
- When and how should I adjust my soil pH, and how long does it take to work?pH amendments work slowly — lime often takes a few months and elemental sulfur several months to a year to shift pH — so apply them in fall or as far ahead of planting as you can, not at planting time, and retest before adding more.
- Is it too late to plant garlic?If the ground isn't frozen yet, it's usually still worth planting. Most guides aim for 1 to 2 weeks after the first killing frost, or a few weeks before the ground freezes, so cloves can root before winter; later cloves tend to root less and make smaller bulbs. If the ground has already frozen, plant as early in spring as the soil can be worked and expect smaller heads.