Manure adds essential nutrients to vegetable gardens, but it may contain pathogens that pose risks both to crops and humans. Many sources advise only using composted or aged manure in edible gardens – cat, dog and pig manures contain parasites which should never be used as they could transmit diseases through eating plants grown there.
Spring
Manure is an integral component of a flourishing vegetable garden, providing key nutrients, improving water retention, and adding beneficial microbes. When applied correctly, manure will help your plants thrive – but too much or fresh manure could pose problems such as burning your plants or spreading pathogens through your garden. For optimal results, manure should be applied during autumn for maximum composting potential before being planted into your beds in spring.
Considerations must also be given to the type of manure used. Fresh animal manure must only be used in non-edible gardens due to possible bacteria such as Salmonella and E coli as well as pathogens like roundworms and tapeworms present, which may transfer directly onto fruits and vegetables and cause foodborne illness in humans – with children, pregnant women, those with weak immune systems or chronic illnesses more vulnerable.
Aged or composted manure is the optimal way to fertilize your garden, as it increases organic matter while also improving soil texture and making roots easier to develop while increasing available nutrients for plant growth.
Aged manure offers several distinct advantages over fresh animal manure: It contains no excess nitrogen and ammonia levels that could burn plants, while at the same time making its nutrients available to your crops.
Aged manure with optimal characteristics will have a dark color and have a C:N ratio of 2:1 or greater. Furthermore, the pile should be thoroughly rotted without large amounts of fresh materials such as grass clippings or weeds; moisture content should also remain low. A properly composted manure will go through a heating process to kill off harmful pathogens; to be certain about this fact ask your farmer or store where you’re purchasing from if their product was hot composted or hot composted
Summer
Manure can help vegetable gardens and allotments increase soil organic matter, mineral, and nutrient content, soil structure, water holding capacity and drainage. Furthermore, organic matter is broken down by microorganisms into plant-friendly nutrients for use by plants; fresh organic matter should ideally be added in fall or spring so it has time for decomposition by microbes and acclimatization to temperature and light conditions; however gardeners often choose well-aged manure in summer or fall as an expedient way of rapidly improving flower beds, vegetable patches or potted flower health.
Manure that hasn’t been properly aged or composted may contain pathogens that threaten crops and spread disease, while raw manure’s high nitrogen levels could burn plant roots or inhibit seed germination.
Therefore, unless your compost pile can reach ambient temperatures, it is wise to wait until fall to add manure to your vegetable garden. Well-aged manure has the ideal combination of C:N ratio and moisture level that most plants and vegetables need for healthy growth.
Even if your manure is well-rotted, it is wise to cover it with a layer of straw mulch or another organic material when spreading it on your garden. This will prevent the manure from being lost through evaporation and washing away during heavy winter rainstorms.
It is also crucial that manure be added when it is raining; heavy rainfall compacts soil and turns manure muddy and sticky, making removal more difficult later. Furthermore, rain can spread pathogens and bacteria found in carnivorous animal manure into soil through runoff and raindrops; should it still rain while adding manure, wait until it stops before adding any more or cover the bed with organic matter to protect its nutrients from leaching into ground water or ditches that could potentially pose pollution risks.
Fall
Well-rotted manure improves soil structure and increases access to essential nutrients like nitrogen for garden plants. Applying it in fall will give gardeners maximum benefit next spring when planting begins. Unlike synthetic fertilizers that burn plant roots while leaching excess nutrients into groundwater, organic materials like leaf mold, rotted manure and compost slowly work their way through soil for improved health, benefitting organisms such as earthworms, bacteria and fungi that help break it down while releasing its nutrients.
As temperatures warm in summer months, vegetable gardens no longer require additional manure to reach optimal growth conditions. Instead, high potassium fertilizers should be applied during fruiting season in order to increase tomato, pepper, and strawberry harvests.
Harmful pathogens found in fresh or inadequately composted animal manure may pose a risk to garden crops and humans alike, particularly root vegetables (beets, carrots and radishes) and leafy greens such as chard or spinach. To reduce this risk pregnant women, children and people with compromised immune systems should refrain from eating unwashed vegetables grown from manured gardens without first thoroughly washing and cooking before consumption.
To select an optimal manure for use in vegetable gardening, it is crucial to select an aged variety with low ammonia levels. An ideal manure would have been exposed to soil for at least six months prior to being added as fertilizer; sampling its nutrient levels can also help determine how much of each nutrient should be applied annually; for more information about sampling and understanding results visit UMN Extension’s webpage.
If you plan to add manure to your vegetable garden this fall, wait until temperatures have cooled off before applying any. Hot temperatures can cause manure to burn or stick to your shovel while digging it in, while rainy conditions could compact soil, making it harder for you to access and dig through.
Cover crops planted in the fall can also provide beneficial results, including increasing nitrogen availability to other plants by converting non-usable forms into forms they can utilize and helping prevent erosion. Cover crops also help hold onto soil in place while helping prevent erosion.
Winter
As seasons change, gardeners turn their focus toward their vegetable gardens. Now is an opportune time of year to add manure as a natural fertilizer that increases soil organic matter and holds nutrients for plants – benefitting both annual and perennial vegetables, fruits and flowers like roses, tulips and sunflowers. Furthermore, adding manure will aid weed control as its high nitrogen content helps the soil hold onto moisture for longer.
Though fresh manure may tempt us, it’s wiser to let it rot for 6-12 months before using it in your vegetable garden. Fresh manure contains high levels of nitrogen which can burn the roots of any plants that come in contact with it as well as bacteria which could potentially contaminate edible crops.
After harvesting and prior to winter, manure should be added back into your vegetable garden for maximum efficiency. Some gardeners pile it up in the fall before sowing heat-loving cover crops like buckwheat or rapeseed that will store nutrients over winter – these cover crops can then be turned under before planting your new crops in springtime.
Gardeners can use aged manure in the fall to amend soil for planting in spring, which is an effective strategy both for new garden beds and existing ones that need amending for spring planting. By doing this, the manure will be ready for use when spring comes around; less work will need to be done digging up existing vegetable beds to incorporate it.
If you choose fresh manure, it should be mixed thoroughly into the existing soil to prevent burning the topsoil and causing root damage. Herbivorous animals (cow, sheep or goat) produce manure with the lowest risk of transmitting pathogens to edible plants, while pelletized or shredded pieces make handling and application easier. It is also helpful if it has been composted as this will have lower C:N ratio and moisture content which reduce the chance of contamination of vegetables with dangerous pathogens.