The following suggestions for fall garden projects help us save precious resources, attract wildlife, increase our harvest, and enrich our lives. Choose one or more to expand your garden’s potential.
Build a hügel bed
Fall is a great time to plan garden beds for next year, particularly those that benefit from sitting through the dormant season. One such bed is the hügel bed, named for the German word “hill” or “mound.” Hügel beds are a form of raised garden bed built from layered organic matter. A lower strata of woody material (fallen trees, logs, or thick branches) nestles beneath other layers of compost, manure, and leaf litter. On top of everything is soil. The overall effect is of a mound or high bed that produces abundant crops with little water or fertilizer.
Built-in fertilizer: The gradual decay of woody debris and other organic matter inside the bed provides a long-term source of nutrients for plants (up to 20 years in a large bed).
No-till: As the wood decays, it leaves open pockets of air that increases soil aeration and prevents compaction.
Sponge-effect: The logs and branches inside a hügel bed store rainwater during the wet season for use during drier times. In a well-constructed hügel bed, you may not need to water after the first year.
Food for microbes: The rotting wood in hügelkultur provides the foundation for a healthy soil ecosystem that includes beneficial bacteria, fungi, insects, and worms.
Here’s how to get started:
Dig a trench about six feet long, three feet wide, and one foot deep. You can forgo the trench, but your overall bed height will be higher. You can also dig within an existing raised bed.
Fill the trench with a layer of logs or thick branches. If they are short enough, you can stand on end to increase moisture wicking. (If you didn’t dig the trench, place the wood directly on the ground.)
Pile smaller branches and sticks lengthwise onto the large logs. This can include twigs and any type of woody shrubs. Water the entire bed heavily to thoroughly soak the wood.
Pack the cracks between the woody layers with leaf litter, compost, manure, grass clippings, sod…any nitrogen-rich material that will help feed decomposition.
Top the whole bed (including any exposed sides) with at least six inches of soil. Your goal is to have a raised bed at least three feet high.
Plant a cover crop over the bed’s surface to increase nitrogen. When your cover crop has finished its life cycle, mulch the entire bed with straw to hold until spring when you would plant as a regular garden bed.
Keep in mind that hardwoods break down more slowly in a hügel bed and will hold more water over the long term than softwoods. Some, like alder, aspen, cottonwood, and poplar, will begin rotting more quickly, releasing nutrients into the soil sooner. Avoid adding woods like black walnut, old growth redwoods, and cedar since these will negatively impact the decomposition process.
Garlic is one of the few crops in North America that does its best growing in the fall and spring. Getting your bulbs in the ground now means a better crop come July, since garlic needs a long growing season to fully develop.
Begin by purchasing disease-free bulbs from a reputable supplier close to home. Garlic adapted for your region will have the best chance for success, so look for varieties with a proven track record in your state or province. Separate each bulb, inspecting the cloves for insects or disease.
Next, prepare the soil. Garlic likes a neutral pH (7.0), so if your soil is too acidic, apply organic-grade lime 1-2 weeks before planning time. If you live in a rainy area, plant your garlic in an area with good drainage or plant in a raised garden bed. Garlic left to the whims of a rising water table is susceptible to rot.
Plant well ahead of first frost date to ensure your garlic can grow before the ground freezes. Your goal is for the garlic to put down roots but not grow too much before winter. That means waiting until there’s a nip in the morning air, but hard frosts have not yet begun. Plant with tips up, about 3 inches deep. If you live in an area with cold winters, resist planting too shallowly, since freezing temperatures will heave the cloves above soil level and you’ll have to start all over again. Ensure you have 6 inches between plants. Water your bulbs to encourage root growth and fertilize with an organic all-purpose fertilizer that isn’t too high in nitrogen.
After the ground freezes, lay down a thick mulch to protect your garlic over the winter and suppress weeds. Avoid anything with seeds (e.g. hay).
Build a compost bin
If your yard or garden doesn’t have a compost bin, now is the time. Fall yard waste and autumn leaves are the perfect compost ingredients. They balance the high nitrogen content of kitchen waste that is generally abundant in most backyard composters. They also speed the decomposition process by giving compost microbes exactly what they want for dinner.
There are many ways to build a compost bin, and what you end up with often depends on what materials you have available. The following materials make quick and easy composters:
A short length of mesh fencing (10-13 feet long) curved into a circle makes an instant compost pile when you’re pinched for time. Choose metal wire 2.5 to 4 feet high set on even ground. Trim to desired length (a 10-foot length makes a 3 foot diameter circle) using wire cutters. Fasten ends together using twine, zip straps, or by folding open wires from one end around closed wires from the opposite side. When it’s time to turn your pile, open or lift the hoop off the ground.
Food-grade plastic barrel
Barrels can act as instant composters with the right preparation, and can even be rolled on the ground like a tumbler to speed composting—if you take care not to fill them too full. Choose a food grade plastic barrel with walls thin enough to penetrate with home tools. Provide proper airflow by drilling holes at regular intervals: using a 5/16 inch drill bit, add holes every 5-10 inches in a grid pattern. Once properly aerated, your barrel will make compost in 3-4 months depending on weather and compost materials.
When lashed together into a square, wooden pallets provide all the support and aeration that compost needs to thrive. And they’re often free! When it’s time to turn your compost, simply open one side of the pallet composter to access rotting materials. Start by finding four pallets the same size and fasten together at two corners using lashing or screws. Next, fasten your “door” on one side using two hinges. Set this pallet slightly higher so it will be easier to open. Fasten the remaining corner using a hook-and-eye latch. Note: If the spaces between the slats on your pallets are too great, compost ingredients may spill out when added. To prevent this, cover the outer surface of each panel with chicken wire, attaching it with heavy duty staples.
Custom-built wooden compost bin
Treated lumber may be toxic: Up until 2002, treated lumber in the United States contained chromated copper arsenate (CCA), which raised concerns about arsenic and chromium toxicity. An agreement between the wood preservative industry and the Environmental Protection Agency saw CCA phased out. It’s replacement, alkaline copper quaternary (ACQ), uses copper oxide and quaternary ammonium to halt decay in wood products. The copper has been shown to leach into soil and compost, particularly those that are highly acidic. Although copper is an essential element for plants and animals, too much can be harmful. While studies indicate copper leaching from ACQ-treated lumber is not likely to be harmful, it’s wise to test your soil periodically for copper levels if you choose to use treated lumber.
Plywood will delaminate: Plywood is made up of many layers of wood held together with glue. When exposed to the high moisture content in compost piles, this glue quickly dissolves leaving you with a bumpy, rotting slab.
Fir, hemlock, and pine are short lived: Use these woods for a temporary pile only—they won’t last long when faced with the moisture and acidity in composts.
Raw cedar is durable and natural: If you want to build a long-lasting wooden compost bin, raw cedar is naturally rot-resistant. Strong oils prevent cedar from breaking down quickly and inhibit bugs from snacking on its fibers. That’s why cedar compost bins need no sealants or treatment. Cedar also weathers to a pale silver-gray, making it blend in with the surrounding landscape.
Once you’ve selected your materials, locate your bin in an area that you can access easily with a wheelbarrow. Layer autumn leaves, grass clippings, yard waste, and kitchen scraps, mixing periodically to speed decomposition.
Mulch your soil
Mulching your soil after harvest prevents weeds from sprouting and taking hold, making your job easier come springtime. But that’s not the only reason to spread mulch on your garden this fall. Mulch protects overwintering crops from temperature extremes and prevents soil nutrients from washing away during times of high moisture. It also builds soil tilth by adding organic matter to the soil over time.
While almost any mulch can work in the summer to prevent weeds, some mulches fare better than others during the fall and winter. Choose robust materials free from weed seeds. This includes:
Technically straw is what’s left behind after a grain harvest, so any remaining seeds should be minimal. However, most straw contains some seeds and may sprout come springtime if not turned when temperatures begin to warm. Purchase bedding straw from your local agricultural supplier and spread thickly for maximum protection.
Free for the taking at this time of year, autumn leaves break down more quickly than straw, making them an ideal addition of organic matter to your soil. Gather leaves by raking around available trees, or ask any neighbors who may have extra. Avoid using leaves from walnut, hickory, camphor laurel, and eucalyptus trees, since these can be toxic to some plants. Shred larger, tougher leaves with a lawn mower if you’re concerned about the mulch forming a dense mat around your plants. Apply a layer of 2 to 3 inches around winter crops. Pile more thickly (6 to 8 inches) to keep beds snug and weed free until winter.
Create a mini bird sanctuary
Adding bird habitat to your garden helps birds weather the cooler days and long nights of fall and winter. It will also provide early spring homes for cavity-nesting birds that help control insect populations come summertime. To create a mini bird sanctuary in your yard or garden, consider carrying out the following tasks:
Birds that overwinter in your neighborhood likely include plant seeds in their diet. Popular perennials like black-eyed Susans, purple coneflower, asters, and blazing stars provide tasty treats for birds to peck and explore. Since perennials do best when divided in cool, moist weather (fall or spring in most regions), now is the perfect time to split any plants you already have and encourage more to grow.
Chickadees, bluebirds, titmice, screech owls, and small woodpeckers will use bird nesting boxes in the fall and winter to conserve heat. Plus, any birdhouses added to your yard or garden now will provide homes for early nesters come springtime—and that means better insect control when bugs are at their peak. This includes garden-loving pests such as aphids, leafhoppers, whitefly, weevils, caterpillars, beetles, and more.Keep in mind nesting boxes must be made from untreated wood, with a sloping roof to keep off rain and weather. If you already have nesting boxes in place, now is the time to clean them out.
Plan new beds and borders
Fall is the time to take stock of what you have and begin planning new additions for early spring plantings. If you’re just starting out, consider adding a songbird border along garden beds. This can include easy-care indigenous plants, seed-bearing perennials, and shrubs that produce cones or berries. Adding a variety of plants will help ensure areas for cover, nesting, and feeding.
Plant a cover crop
Fall is the best time to plant cool season grasses. A cover crop of fall rye in your dormant vegetable beds will provide delicious food for birds seeking grains and seeds come wintertime. Plant when soil temperatures are between 50 and 65 degrees Fahrenheit or when daytime temperatures are between 60 and 75 degrees.
Plant spring-flowering bulbs
When the ground temperature dips, that’s the time to plant spring-blooming bulbs. These plants require a period of cold-temperature dormancy to stimulate root growth, so the best time to tuck them into the ground is when evening temperatures hover between 5°C to 10°C (40°F to 50°F) or about six weeks before the ground freezes. A new bed carefully prepared in fall will reward you with a colorful display from April to June. Group like bulbs together in swaths to create a stunning visual statement. Ten or more of each variety is a great start.
Since most spring bulbs benefit from full sun (six hours or more of direct sunlight), choose a location that receives adequate sunshine. Keep in mind that early blooming bulbs can thrive happily beneath deciduous trees that have not yet leafed out.
To ensure a long-lasting display, choose varieties that bloom at different times.
Early spring: Crocuses, scilla siberica, iris reticulata, snowdrops, snow glories, winter aconite, anemone blanda, early mini daffodils, and early tulips.
Mid-season: Hyacinths, narcissi, fritillaria, some anemones, double daffodils, and mid-season tulips.
Late spring: Dutch iris, bluebells, ranunculus, late daffodils and tulips.
Although you don’t usually need to fertilize bulbs in the first year, doing so will help them with subsequent displays. Plant in well-drained areas with sandy or loamy soil, avoiding clay which may hold water and take a long time to warm up in spring, causing your bulbs to rot. If you have problems with squirrels, consider mixing in allium bulbs to deter these critters from digging. Finally, if you’re planting in patio containers, be sure to plant close to the center to protect from frost.