By: Laura Miller
Perhaps you’ve heard composting potato peelings is not agood idea. While you need to be careful when adding potato peels to compostpiles, composting potato peelings is beneficial.
Potatoescontain nutrients such as nitrogen,phosphorus,potassiumand magnesium.Composting potato peelings adds these nutrients to the pile and benefits theplants that will eventually be grown using that compost. So why thecontroversy?
The problem that can arise from adding potato peels tocompost piles is that whole potatoes and their skins can carry potatoblight. This is a fungal infection which affects both tomatoand potato plants. Potato blight spores survive from one season to the next byoverwintering on live plant tissue. Infected potato tubers are the perfecthost.
The symptoms of blight on potato and tomato plants includesyellow patches with brown centers on the leaves and dark patches on potatotubers. This is followed by the potato tubers rotting from the skin toward thecenter and eventually turning into a soggy mass. Unchecked, potato blight canwipe out entire crops of potatoes and tomatoes. There is reason for concernwhen it comes to adding potato peels to compost piles.
Luckily, avoiding the spread of blight when compostingpotato peelings can be accomplished by following a few simple precautions:
Following these precautions will help keep the compostpile active and generate sufficient heat to kill fungal spores. This makesadding potato peels to compost piles perfectly safe!
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Read more about Compost Ingredients
One thing you'll note about the worm foods on this list is that most are moist, soft, and/or low in acidity. As a general rule, you should feed worms a mix of equal parts "brown" and "green" foods. Browns are high in carbon and carbohydrates, while greens add a lot of nitrogen and protein to the soil.
Greens include green vegetables and other natural foods—melon rinds, lettuce, carrots, fruit peels, etc.—and they don't have to be green. Browns may be food or non-food items, such as coffee grounds, paper, egg cartons, or dry leaves. If desired, you can grind up the food for your worms, in a food processor or manually. This blends the foods scraps nicely and makes them easier to eat.
Here are some of the most popular items on worm menus:
If you do not have the space for an outdoor compost, you can decompose sweet potato skins and other vegetable waste indoors by composting with worms, called vermicomposting. You can buy boxes or bins designed for this purpose. You fill the special box with shredded paper and 75 percent water. To this you add redworms (Eisenia foetida) who thrive and happily eat your sweet potato skins at a temperature between 50 and 70 degrees Fahrenheit. Health worms in a vermicompost box can consume 4 to 6 pounds of sweet potato skins and other food scraps each week. In four to six months, the worms can consume all of scraps and shredded paper into “castings,” a nutrient-rich compost that you can use for plant food.
I take it you're not Irish!
The only reason for not composting potato peelings is that they are a potential source of the fungus that causes potato blight. Blight spores can survive only on living plant material. Potato peelings can provide this when the buds in the eyes of potato skins grow into potato plants. To ensure that the peelings don't sprout, bury them well down in the compost and ensure that you turn the heap regularly. If you do this, it is fine to compost the peelings.
In most of the United States and Canada, Phytophthora infestans requires a living host to survive between seasons. Usually it lives in infected potato tubers, which can survive in storage or the soil (to become volunteers) after harvest or anywhere potatoes might be discarded. Tubers that have been discarded at any stage of crop production or handling (harvest, storage, shipping, spring cleanup, or planting) are known as "culls." Culls may survive if they are not destroyed (frozen, crushed, composted, or buried at least 2 feet beneath the soil surface). Infected tubers that are planted or cull tubers that survive the winter may be sources of the pathogen that initiate epidemics the following season.
They can start growing again in the compost. That in itself isn't a big deal, since you an always pull up the plants, shred them, and recompost them.
The more serious issue is that you may be infecting the compost with assorted fungus and virus diseases, Potato blight is the most obvious risk but potatoes can also carry viruses that affect related species, e.g. tomatoes. Viruses will never be killed by composting - if you want to recycle the organic waste, burn it and use the ash. If you get potato blight fungus in your soil, it will take years to eradicate it.
Note, the diseases are carried in the leaves and stems, not just in the edible bits of the plant! Composting kitchen waste containing cooked potatoes is unlikely to be a problem.
I think it all depends on the temperature that the compost reaches. Cold will not kill a potato since they are exothermic they store heat in their mass which helps them resist cold. Heat from a compost heap will dramatically weaken them - a good compost pile will reach 70 deg C pretty easily, weakening the tubers in the pile and making them vulnerable along with many fungi. And since at the time we are composting new potato haulms and recycling our old stored sprouty spuds there is plenty of fresh material going to the compost it's an ideal time to dispose of them. Right now my compost is running extremely hot with grass clippings, squash vines, spuds, ragweed, pigweed, . A week ago it was six feet high, now down to three feet. A year from now when I use it there will be no sign of spuds at all.
From the point of view of an institution providing general advice, I guess they have to take into account all types of households: some will take composting seriously, keep a hot pile and will ignore the advice, others will end up with a slimy mess, a source of infection for other serious gardeners and the agriculture industry. It's probably best for general advice to err on the side of caution.
QUESTION: Can I just throw kitchen scraps in my garden?
ANSWER: Pretty much. One method of composting is called trench composting, which, instead of letting compost break down and mature before adding it to the soil, kitchen scraps are just tossed into the soil in a trench and buried under a layer of soil in order to decompose directly in your garden beds.
Just keep your kitchen scraps in a container with a lid, like a bucket, saving back potato peels, fruit and vegetable scraps, citrus peels, greens, bread, coffee grounds, and eggshells that you would otherwise throw away. Once the container or bucket starts to fill up, take it out into the garden, dig a trench between two crop rows or in an unused bed and spread the kitchen scraps out into the trench and bury them with soil.
In around six weeks, the kitchen scraps that you buried should have decomposed and you should be left with some high-quality, nutrient-rich humus. As the kitchen scraps are decomposing, don’t plant anything directly over them in the trench until the compost has matured. However, growing crops will not mind the composting of scraps taking place between their rows. Trench composting is by far the simplest method in which you can recycle your food waste to the benefit of your garden soil.