Using compost in potted plants is a great way to provide nutrients and improve soil health. As an avid indoor gardener I’ve found that compost can really take your potted plants to the next level. In this complete guide I’ll walk you through everything you need to know about using compost for indoor and outdoor container plants.
What is Compost and Why Use it?
Compost is organic matter that has decomposed into a rich, soil-like material. It’s produced through the process of composting, where microorganisms break down organic wastes like food scraps, leaves, and grass clippings.
Adding compost to potting soil provides a wide range of benefits
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Nutrients: Compost contains macro and micronutrients that are slowly released, feeding plants over a longer period of time. This includes nitrogen, phosphorus, potassium and many more.
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Soil Structure: Compost improves soil texture, creating a better environment for roots to grow. It enhances drainage in heavy soils and helps retain moisture in sandy soils.
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Soil Health: The microorganisms and organic matter in compost boost overall soil health. This helps suppress plant diseases and encourages healthy root development.
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Sustainability: Making your own compost reduces waste going to landfills. It’s a free, organic source of nutrients for your plants!
Making Your Own Compost
While you can purchase compost, making your own at home is simple, affordable and eco-friendly. Here’s a quick overview of how to make compost:
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Choose a compost bin: An open pile, enclosed bin, or tumbling composter will all work. Make sure it has good airflow.
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Add greens and browns: “Greens” provide nitrogen (e.g. food scraps, grass clippings). “Browns” provide carbon (e.g. leaves, wood chips). Use 2-3 parts browns to 1 part greens.
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Mix and maintain: Turn or stir the compost every 1-2 weeks to introduce oxygen. Keep the pile moist but not soaked.
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Let it break down: With proper conditions, compost should be finished in 2-3 months. It will look dark, crumbly, and earthy when ready.
Using Compost in Potted Plants
Once you have quality finished compost, it’s time to put it to work in your container plants! Here are some tips:
Potting Mixes
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Aim for a ratio of 1 part compost to 1 part potting soil as a general guideline when making potting mixes.
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For seed starting mixes, use a lower concentration of compost like 1 part compost to 2-3 parts potting mix. Too much compost can burn young seedlings.
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Thoroughly mix the compost and potting soil together before filling containers.
Topdressing
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Spread a 1-2 inch layer of finished compost over the soil surface around established plants. This “topdressing” slowly releases nutrients.
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Focus on applying compost around the drip line of the plant, not directly around stems.
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Topdress container plants once or twice per year for a nutritional boost.
Compost Teas
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Brew up some compost tea by steeping mature compost in water for a few days. Strain and apply the nutrient-rich tea to potted plants by watering it in.
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Use compost tea to provide soluble nutrients and beneficial microbes right away, in addition to longer-term compost applications.
Ongoing Maintenance
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Check soil nutrient levels with a soil test annually. Adjust compost amounts based on needs.
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Watch for signs of overfertilization like leaf burn. Flush soil with plain water if necessary.
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Replenish compost levels every year either by topdressing or repotting plants in fresh compost-infused soil.
Troubleshooting Issues with Compost
While compost offers huge benefits, you may encounter some potential issues along the way:
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Poor finished compost: Use a diverse mix of materials, turn the pile, and ensure proper moisture to prevent unfinished compost.
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Bad smells: Anaerobic conditions create foul odors. Introduce more oxygen through turning and adding browns.
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Pests: Avoid meat, oils and pet waste in compost. Use enclosed bins to keep rodents out.
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Weed seeds: High temperatures in active compost piles kill most weed seeds. Screen finished compost to remove any stragglers.
Patience and proper composting techniques will help overcome any challenges. Don’t hesitate to adjust your methods to create the perfect finished product for your potted plants!
The Benefits of Compost in Potting Mixes
By now it should be clear that compost offers tremendous advantages for container gardening and houseplants. Here’s a quick recap of some of the top benefits:
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Adds a broad spectrum of macro and micronutrients
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Improves moisture retention and soil structure for healthy roots
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Promotes beneficial microbial activity to suppress diseases
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Enhances drainage in heavy potting mixes
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Provides nutrients for several months as compost slowly breaks down
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Is a sustainable method of fertilizing plants and recycling organic waste
Potted Plant Composting Tips
After reading this guide, I hope you feel confident to start reaping the benefits of compost in your indoor and outdoor potted plants. Here are a few final tips to help you get started:
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Start small by making a simple compost pile with materials you have at home.
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Use finished compost to amend your regular potting soil for an extra nutrient boost.
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Topdress containers with fresh compost layered lightly on the soil surface once or twice per year.
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Brew compost tea to provide an immediate dose of nutrients and beneficial microbes.
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Adjust compost amounts based on each plant’s needs and your soil test results.
Growing thriving container plants isn’t difficult with the power of compost! Turn your food scraps and yard waste into “black gold” for your potted plant collection. Your plants will thank you.
4 Ways to Use Compost in Your Garden
All types of soil benefits from amending the soil with organic matter, and compost is an excellent way to do that. Organic matter is key for soil productivity, it improves the soil texture, microorganism activity, and nutrient uptake. Even rich, good-quality loamy soil gets compacted over time and adding organic matter loosens up the soil. Sandy soil with its large soil particles does not hold water and nutrients very well and amending it with organic matter helps the soil retain moisture better so that it does not drain faster than the plants can absorb water and nutrients. Clay soil with is dense soil particles sticks together, which leads to poor drainage and insufficient oxygen. Adding organic matter to heavy clay soil loosens it up and improves aeration.
Adding organic matter in the form of compost to soil also improves the soil’s ability to hold key nutrients such as calcium, magnesium, potassium. The acids in organic matter help plant roots with the uptake of water and nutrients and makes soil minerals available to plant roots by dissolving them. By adding compost to soil you furthermore keep the soil pH stable because a pH that is off kilter also affects the plants’ nutrient availability and uptake.
Only 3 to 6 percent of soil consists of organic matter so as important as compost is, it is used in moderate amounts but applied repeatedly over time, about once a year. Spread a layer 2 to 3 inches thick over the soil and incorporate it with a tiller, shovel, or a garden fork.
For Potted Plants
Just like in garden soil, mixing mature compost into your usual potting mix for container improves its water-holding capacity. Keep in mind though, that in the confined space of a container, too much compost can lead to root burn from the excess phosphorus in the soil. You can either spread a layer of 2 to 3 inches thick on top of the potting mix, or combine up to 30 percent compost and 70 percent potting mix to fill the container.
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How to Add Compost in the Garden
FAQ
Can I just put compost on top of soil?
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Top Dressing:Instead of mixing compost into the soil, you can spread a layer of compost on the surface, which is a no-till method.
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Benefits of Top Dressing:
- Improves Soil Health: Compost adds organic matter, which improves soil structure, water retention, and nutrient availability.
- No Soil Disturbance: Top dressing avoids disturbing the delicate soil ecosystem, including beneficial microorganisms and mycorrhizal fungi.
- Easy Application: It’s a simple process, just spread the compost on the soil surface.
- Improves Soil Health: Compost adds organic matter, which improves soil structure, water retention, and nutrient availability.
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How to Top Dress:
- Apply a thin layer of compost (about 1/2 to 1 inch) on the soil surface, around the base of plants.
- Ensure the compost doesn’t directly touch plant stems.
- Rain and other natural processes will gradually incorporate the compost into the soil.
- Apply a thin layer of compost (about 1/2 to 1 inch) on the soil surface, around the base of plants.
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When to Top Dress:
- You can top dress at any time of year, but it’s particularly beneficial in the spring and fall.
- You can also top dress before planting or after harvesting.
- You can top dress at any time of year, but it’s particularly beneficial in the spring and fall.
How often should I add compost to my potted plants?
If you’re growing a tree or shrub in a large container, you should replenish the compost every year or two.Mar 29, 2021
Can I just use compost in pots?
Compost can be used as part of a potting soil mix, but it’s best to blend it with other materials like perlite or sand to improve drainage and texture for container plants.
Can you put compost on top of a plant?
You can avoid disturbing the soil and adding an inch of compost on top of the soil itself. When you water the plant, the nutrients from the compost will leach into the soil. If you have little compost, you can add it near the base of the plant rather than cover the entire potting soil. Just keep some space, so the compost does not touch the plant.
How do you add compost to potting soil?
Add the compost to potting soil when preparing it. Mix 25% compost with 75% potting soil. Add some sand or perlite if you want more drainage so water does not get trapped and rot roots, which can lead to plants dying from a lack of oxygen (phytotoxicity). Every two months, add 1-inch of compost to the top of the potting soil.
Do you need to use compost in potting soil?
You need to use compost in moderation in the potting soil. Too little of the compost will not benefit the potting soil. Too much of the compost can cause over-fertilization as the nitrogen, potassium, or phosphorus increases in the soil. Too much compost will not give the right stability for the plant to grow.
Is compost good for houseplants & potted plants?
Compost is good for houseplants and potted plants because it adds nutrients such as nitrogen, potassium, phosphorus, calcium, magnesium, sodium to the potting soil. It introduces beneficial organisms to the potting soil that help improve texture and add nutrients.
How do you use compost in a container garden?
Refreshing the old soil in your large pots with a mix of compost and potting soil can give existing plants a nutrient boost too! Side dressing is another excellent way to use compost in your container garden. It’s the gardening equivalent of adding a little extra topping to your favorite dish for an added flavor boost.
Why is compost good for potting soil?
The organic matter in compost helps improve the texture of the potting soil. This helps get better aeration in the potting soil. The compost also improves the soil’s ability to hold nutrients and water, which is essential for plant growth in a potting mix that does not contain any fertilizer or organic matter in it. 3. Improves pH level of the soil