Fall is the best time of year to prepare soil. The beds are emptying as summer crops finish, the soil is still warm enough for organisms to work, and anything you add now — compost, manure, lime, cover crops — has months to break down and settle before spring planting. Soil prepared in fall is alive and ready in spring, while soil left bare and untouched over winter is often compacted, leached and lifeless by the time you need it. A few hours of fall soil work saves weeks of catching up in spring, and it is the foundation that everything else in the garden depends on.
The fall soil routine is simple: clear, test, improve, protect. Clear spent crops and weeds. Test the soil if you have not done so recently. Improve it with compost and organic matter. Protect it with mulch or a cover crop so it is not left bare through winter. This guide works through each step, explains how different soil types need different treatment, and covers the mistakes that undo good soil work. If you are unsure about your soil type or what it needs, check your local extension service, which can test soil and advise on amendments for your area.
Clear the beds first
Start by clearing spent summer crops. Pull up finished annuals, tomato plants, beans and other crops that have finished, and compost healthy material. Do not compost diseased plants unless the heap runs hot — bag diseased material and dispose of it instead, since our powdery mildew treatment and early blight tomatoes guides explain how disease survives in garden waste. Pull weeds before they set seed, since a weed allowed to seed in fall becomes many weeds in spring, and remove fallen fruit and debris that harbour pests and disease. Our fall garden cleanup guide covers the full tidy-up.
Do not leave roots of finished crops to rot in the bed unless they are healthy legumes, whose roots add nitrogen to the soil; most other roots are better removed. Loosen the soil lightly with a fork, working from a board or path so you do not stand on the bed and compact it. Do not dig wet soil, which smears into clods that set hard, and do not dig more than you need to: the aim is to loosen the top layer and mix in organic matter, not to turn the whole bed upside down. No-dig gardeners can skip digging entirely and simply spread compost on the surface, letting worms do the mixing.
Test your soil in fall
Fall is an ideal time to test soil, because the results tell you what to add now, and amendments applied in fall have months to work before spring. A basic test measures pH and the main nutrients, and it costs far less than the fertiliser wasted by guessing. Our soil pH testing guide explains how to test, what the numbers mean, and how to take a good sample. Most vegetables and flowers grow best in soil that is slightly acidic to neutral, and a test tells you whether your soil is far from that range and what to do about it.
If the soil is too acidic, lime applied in fall has months to react and raise the pH before spring. If it is too alkaline, sulphur or acidic organic matter can help, though changing alkaline soil is slow work. Our acidic soil and alkaline soil guides cover both cases. A test also tells you whether the soil is short of a specific nutrient, so you can add what is missing rather than a general fertiliser that adds what is already there. Retest every few years, and keep a note of the results so you can see whether the soil is improving over time. If you are unsure how to interpret a test, check your local extension service, which can explain the results for your soil type.
Adding compost and organic matter
Organic matter is the single most useful thing you can add to any soil, in fall or any season. Compost improves drainage in clay soil, holds moisture in sandy soil, feeds soil organisms, and adds nutrients slowly. Spread a layer of compost over beds in fall, either working it into the top few inches or leaving it on the surface for worms to pull down over winter. Our composting basics guide explains how to make compost, and our fall composting guide covers the autumn composting routine. Well-rotted manure can be spread on empty beds in fall in the same way, but never use fresh manure, which burns plants and can carry pathogens, and never use it on food beds close to harvest.
Leaf mould is another excellent fall soil improver, and fall is when leaves are plentiful. Shredded leaves worked into beds or spread as a mulch break down over winter and lighten heavy soil. Our leaf mulch guide covers leaves in detail. Biochar and vermicompost are other options for gardeners who want to go further — see our biochar for garden and vermicompost guides — but for most gardens, a good layer of compost is enough. Do not add sand to clay soil, which makes it set like concrete; add organic matter instead, which is the only reliable way to improve clay. Our clay soil improvement guide explains why.
Cover crops: living soil protection
A cover crop, also called green manure, is a plant sown on empty beds in fall to protect and feed the soil over winter. Cover crops stop rain washing nutrients away, stop wind eroding the surface, suppress weeds, and add organic matter when they are dug in during spring. Legume cover crops such as clover fix nitrogen from the air into the soil, which is a free fertiliser for next year's crops. Our cover crops for soil and green manure guides explain which cover crops suit which beds and how to sow them.
Sow cover crops early in fall, while the soil is still warm enough for them to establish before cold weather. Scatter seed over a cleared, loosened bed, rake it in lightly, and water if the weather is dry. In spring, cut the cover crop down and dig it in a few weeks before planting, so it has time to break down; digging it in too late can temporarily use nitrogen as it rots, which starves the crop that follows. If you do not want to sow a cover crop, a thick mulch of leaves, straw or compost protects the soil in the same way, and our fall mulching guide covers mulching empty beds.
Fixing drainage and compaction in fall
Fall is a good time to fix drainage and compaction, since you can see where water sits after autumn rain and you have months before spring planting. If beds stay wet, the cause may be compacted soil, a low spot, or heavy clay, and the fix depends on the cause. Our soil drainage improvement guide explains how to diagnose and fix wet beds, and our soil compaction guide covers compacted soil specifically. Adding organic matter helps both problems, since it opens up clay and helps sandy soil hold water, and raising beds is often the simplest fix for soil that stays wet. Our raised bed soil mix guide gives a mix for raised beds that drains well.
Do not walk on wet beds, which compacts them, and use boards or permanent paths to reach the middle of beds without standing on the soil. Fork compacted beds lightly in fall when the soil is moist but not wet, working in compost as you go, and let frost do some of the work: frost breaks up heavy soil over winter, which is one reason fall preparation works so well. If a bed is badly compacted, a cover crop with deep roots can help break it up over winter. Check your local extension service if drainage problems persist, since they may be caused by something below the surface that needs a different fix.
Putting beds to bed for winter
Once beds are cleared, tested, improved and protected, they are ready for winter. A bed put to bed properly in fall needs little work in spring beyond a light fork and a top-up of compost. Label beds if you rotate crops, noting what grew there this year so next year's planting plan avoids putting the same family back in the same place, which lets pests and disease build up. Clean and store tools, drain hoses and irrigation, and put away pots and trays so they do not crack in frost. Our fall garden cleanup guide covers the end-of-season tidy, and our winter soil preparation guide covers what can still be done once winter arrives.
Do not leave beds bare over winter if you can avoid it. Bare soil loses nutrients in rain, loses structure in wind, and loses soil life as it dries and freezes. A mulch, a cover crop, or even a layer of cardboard weighed down with compost is better than nothing. And do not feed beds that are resting with strong fertiliser in fall, since the nutrients will wash away before spring; our fall fertilizing guide explains why soil feeding and plant feeding are different jobs. Feed the soil with compost now, and feed the plants in spring when they can use it.
Frequently asked questions
What is the best thing to add to soil in fall?
Compost. It improves any soil type, feeds soil life, and has months to settle before spring. Well-rotted manure, leaf mould and cover crops are also excellent. Avoid fresh manure and strong synthetic fertiliser in fall.
Should I dig my beds in fall?
Lightly, if the soil is moist but not wet. Loosen the top layer and mix in compost, but do not dig wet soil, which compacts into clods. No-dig gardeners can skip digging and spread compost on the surface instead.
Is fall a good time to test soil?
Yes, it is one of the best times. A fall test tells you what to add now, and amendments such as lime have months to work before spring. See our soil pH testing guide.
What is a cover crop and should I sow one?
A cover crop is a plant sown on empty beds to protect and feed the soil over winter. It stops erosion, suppresses weeds and adds organic matter when dug in during spring. Legume cover crops also fix nitrogen. See our cover crops for soil guide.
Can I leave beds bare over winter?
It is better not to. Bare soil loses nutrients and structure in winter rain and wind. Cover beds with mulch, compost or a cover crop. If you are unsure what suits your soil, check your local extension service.