When you’re trying to get the right mixtures in your garden, you might be thinking of how you’re going to determine how much compost to mix in.
Determining how much compost to use is important to save money and if the mixture is healthy for your plants, but how do you know how much to add?
The amount of compost will be dependent on the type of plant you are amending, but generally when you’re topdressing soil with compost you want to apply an add of between of half of an inch and quarter of an inch.
When you amend soil worse off the compost preplanting, you can apply approximately one to two inches.
How Much Compost Should I Mix with My Soil?
Some plants require more nutrients than others, and if you are dealing with vegetable plants, like tomatoes, eggplants, squash, melons, etc., you may want to incorporate more than just a handful of manure or compost.
In most cases, you adding about half an inch if adding the compost to the soil surface should be fine.
Did You Know: You may be able to find a compost calculator online for your area. This should help you get a good idea of exactly how much compost or manure you want to work into that plot of soil.
How Much Compost Should I Use in Raised Beds?
When constructing raised beds, you may want different quantities of compost.
To grow healthy plants, using two or more inches of good quality compost combined with soil should be adequate.
If you want vegetables in your raised beds, consider more compost for better plant growth.
How Much Compost Should I Use in a Pot?
You will almost always want to stick with thirty percent or less compost in any container.
Your plants should be fine, even heavy feeders, if you are applying plant food on a regular basis, and even if you are not and have your other inputs dialed in. More than this will be too much for your plants and could possibly burn the roots.
Seedlings in particular are touchy if they are grown in too much compost and will not do well, using pots full of compost or an unbalanced growing medium.
Common Mistake: Be careful with the ratios, especially when planting seeds!
How Much Compost Should I Use on a Lawn?
At times, you may wish to boost the nutrients in your lawn.
This is typically done over a much larger area, but it is also important to not add too much compost; too much can burn the grass, and it can create a thick layer that the grass will not be able to grow through.
However, if it has been a while since you last fed your grass, you can apply up to one half inch of compost evenly over the top of the lawn.
If you are refilling bare patches, you can go up to one half inch deep and then rake it over the soil.
How Much Compost Should I Use on My Garden?
If you’re simply incorporating compost into your garden, enhancing the nutrients available to your plants and flowers alike, then you should be adding between one inch and two inches of compost, and then digging it in.
Ideally, you would like to dig it around six to eight inches beneath the surface of the soil, as the majority of plants grow downwards.
While it is fine to also use compost as mulch on top of the soil you may want to reduce the amount you are using.
Eventually, the nutrients will wash down into the soil, but you also don’t want to apply too much compost for the plant’s stems to burn.
How Much Compost Should I Put Around Shrubs?
When planting a new shrubby specimen, mix in roughly twenty-five percent in compost and seventy-five percent in soil from your yard.
This should provide the tree or shrub with enough nutrients to grow with, but not so much to suffer from an excess of nutrients.
Depending on the specific tree or shrub variety, you might want to add some plant food a few months later, but the compost will nurture the tree or shrub for quite a while.
How Do I Add Compost to My Garden?
Many garden writers endorse the practice of spreading compost on the surface of the soil whenever you can instead of mixing it in.
Certainly, you can mix it in if you are planting in a pot or filling raised beds, but if you are only improving the soil, simply spread the compost on top of the soil.
There is a belief that this is healthier for the garden, because mixing soil or digging it up disturbs the soil. There are networks of fungi called mycorrhizal fungi that help the plant access nutrients deep in the soil.
When you dig up the soil, you interrupt the delicate strands of the fungi and lessen the plant’s ability to access nutrients.
Of course, if you are improving the structure, it typically makes sense to mix and dig it in, because it does improve aeration and moisture retention properties.
Remember, both clay and sandy soils are improved by mixing in and digging in compost whenever possible.
When Should I Add Compost to My Garden?
In early spring, you should be adding a little compost to your garden, which will give your plants a little boost as they are starting their growth period.
A half inch should be plenty in most cases. In the fall and winter, when plants are not growing as much, you can add a little more compost to the garden.
The compost will break down slowly and spread through the soil during the winter, building up nutrients without overloading the plants.
Summary
In general, you will not want a ratio of compost in your soil greater than thirty percent. For heavy feeders, you can probably get away with twenty-five or thirty percent, but for light feeders and seedlings, you will likely want to scale back.
If you add too much food, you can burn a plant’s roots, and in turn, the plant can wilt. So watch out!
If you can avoid it, do not mix the compost in. Just put it on top unless you genuinely need the structural benefit that compost provides.