It’s no surprise to anyone that compost is a very valuable asset in the garden, and a wonderfully natural way to add all the nutrients your plants need. There isn’t much to it. Compost is just decomposed organic material, and something anyone can make for themselves.
But do you know the best way or the best time to use compost in the garden? Are you confident in the waste you’re going to be tossing into your bin?
Get a bit more information on composting, and your garden will thank you for it.
How to Use Compost in Your Garden
The simplest way to use compost in the garden is to just mix it into the soil. After everything warms up in the spring, give your garden beds a good tilling and mix in your compost to start the season off right.
Part way through the summer, you can give everything a second dose by applying more compost. But now that your plants are established and growing, you can’t really just dig up the soil and mix in compost.
Just shovel a layer in around the plants on the surface. Water will still seep through and draw the nutrients down into the soil for the roots. This is known as “top dressing.”
An alternative is to dig your compost under the surface, but off to the side of the plant so you avoid doing damage (“side dressing”). This is good for larger plants that have a wide span of roots that can still benefit from the nutrients at a distance from the main stem of the plant. Just don’t dig too deeply.
This type of mid-season compost use is best done for plants that require a lot of nutrients, such as tomatoes, bell peppers, squash, onions, cucumbers or pumpkins.
Another option that can work, especially for houseplants, is to soak your compost in water, and then use the water as a fertilizer. Sometimes called “compost tea“, this is a lot more convenient than trying to dig into your indoor plant containers to mix in solid compost.
Get a large bucket, and fill it about 1/3 with good compost. Add water to fill up the rest of the bucket, and let it all sit and steep for a few days. Give it a stir once or twice each day.
After about 4 days, strain out all the solids, and that nutrient-rich water is now your compost tea. The solid bits can just back in the compost bin, or added to the garden on their own.
Now you can use that water as a liquid fertilizer on your indoor plants. Not necessarily in place of their usual plain water, but as a nutrient boost periodically.
What Goes in a Compost Bin?
This is probably the biggest mystery to compost novices: what can I compost? Probably more than you realize, but there are a few restrictions.
First of all, these can all be added to your compost bin:
- Fruits or vegetables, including rinds, peels, pits, seeds, leaves, stems, stalks and any already cooked leftovers
- Leftover pasta
- Stale bread
- Coffee grounds
- Used paper coffee filters
- Egg shells
- Used paper towels or tissue
- Grass cuttings *
- Other yard waste*
The trick is getting the right balance between the types of material. Kitchen scraps and fresh grass clippings are high in nitrogen, and referred to as “green” composting materials.
Branches, dead leaves, straw or wood chips are much higher in carbon, and those are the “brown” items. You need to have a balance between the two in order for the composition process to work right.
Too much green, and it will just rot into liquid mush. Too much brown, and there won’t be enough nutrients in the compost to make it worthwhile.
Don’t worry about getting out the calculator to have the precise ratios perfect. That’s not really the point. Just keep in mind that you can’t lean too heavily to one side or the other.
Keep a mix of green and brown to have a properly active pile. Roughly half and half works well.
The main items you should leave out of your compost are meat and dairy products. They don’t decompose the same, and are far more likely to draw animal pests to your composter (more on that below).
Also leave out any plant material that is contaminated with fungus or harmful mildew. Spores can survive for quite some time, and will end up back in your plants when you use the compost in the garden.
How to Make Compost
Now that you know what goes into compost, you need to know how to make it work. The traditional compost bin (view on Amazon) is the most common, and can be a fine place to start if you are new at using compost in the garden.
They are easy to find online or at the gardening store, with various models, sizes and features to choose from. A standard version looks a lot like a big trash can, with a few holes for air flow and lid.
Bins built on an axle so they can be rotated to tumble the ripening compost inside is nice but they tend to be fairly small.
Holes are necessary for air, and also to allow access to insects and worms that help with the decomposition process. No compost bin is an island. Having bugs in it is actually necessary and should not be discouraged.
Though keeping everything contained in a bin can be helpful and a little more appealing to the eye, it’s not strictly necessary. You can get compost from a simple pile, or a larger type of enclosure.
But a pile of rotting food waste isn’t that appealing in a yard, so it’s more common to keep it under cover. Any large container can work, providing it has vents or holes, as already mentioned.
Compost also needs to be damp in order to decompose properly. A lidded bin can get too dry inside, especially during summer heat. You may need to give it a watering, just like your plants.
And speaking of seasons, you can keep on adding to your compost collection even in the winter. It will freeze, and there won’t be any insects around but that won’t do any harm. Keep adding fresh scraps, and things will thaw out naturally in the spring.
Keeping Animals Out
Unfortunately, what you consider kitchen garbage is going to be considered a dinner buffet to a lot of animals living outside your home. Mice, rats, squirrels, skunks and raccoons will all be very interested in getting at your compost.
That means you need to be thinking of security when setting up your compost spot. A solid bin with a latching lid may be necessary.
If you are going larger-scale composting, you will have to enclose your pile with small-mesh wire fencing. Chicken wire may work but the holes are big enough that mice, chipmunks and small rats will still be able to come and go as they please.
Do not use any poisons to deter the rodents or you will contaminate your compost.
Other Natural Fertilizers
Compost provides a full spectrum of nutrient compounds, and is one of the very best ways to feed your plants. But on those occasions when you are only deficient in one or two nutrients, you need to have a way of fine tuning your fertilizer.
Nitrogen – Nitrogen is one of the main nutrients you have to supply for your plants, and compost is an excellent source of it. So is animal manure (no cat or dog waste though).
Coffee grounds, fish emulsions, and blood meal are other nitrogen-rich options. You can also add nitrogen to the soil over the longer term by growing a few legume plants, like pea or bean, and digging them back into the soil at the end of the season.
Calcium – You can add some extra calcium to your soil with crushed egg shells, dolomite lime, or bone meal.
Potassium – Bananas can add potassium to your soil, though that may not be too practical with a large garden patch. Wood ash or seaweed emulsions are possibly better materials for your plants.
Ash can change the pH (making the soil more basic) so use sparingly, unless you have a problem with acidic soil.
Phosphorus – The last nutrient that you may have to augment in the garden is phosphorus, and you can give that a boost with fish emulsions and bone meal.
Fish emulsion, which you can get at the garden store, is also high in nitrogen so you need to be careful you don’t overdo it.
A note on manure. If you are lucky enough to have access to good animal manure, you don’t use it the same way you use compost in the garden.
Fresh manure has far too much nitrogen in it, and it will be harmful to your plants. It needs to age for several months to further break down, to become suitable for fertilizer.
Buying packaged manure from the garden store is fine, as it would already be aged and ready to use.
If all of this seems too overwhelming, don’t worry. You don’t necessarily have to have your own bin to use compost in the garden. Most gardening or home improvement stores will sell bags of the stuff, just ready to go.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.