Great gardens begin with good soil.
And for Andrew Miano, Senior Horticulturist at Baker Creek, good soil begins with plenty of organic matter.
“I like to think that you can start anywhere,” Andrew says. “All soil can be made better. If you have too-sandy soil, you need to add organic matter, so you don’t have to water as much. If you have heavy clay soil, you may need to add more organic matter so that it drains better, or sand or something like that.”
Not All Compost is Created Equal
Compost comes in all kinds of forms, from fine and sandy to chunky and chock full of wood chips. While woodier compost takes longer to decompose, Andrew says, it’s certainly still a healthy option for garden plants.
“Compost is probably one of the best friends for a gardener. Making it yourself, knowing what inputs are in it, is a good idea.
“That’s really the main thing – organic matter to help enrich your soil. Things like teas or extracts from healthy compost, or vermicompost, with worms, are really great for your garden, especially in organic practices,” Andrew says.
Andrew recommends sourcing your compost locally or making it yourself.
“I would start locally. Do some due diligence. Find out what you have available in your community. Reach out to a local nursery or garden store; find a professional who can lead you in the right direction, because the internet can take you a million different ways,” he says.
Finding a reliable source helps ensure that you’re not putting something into your garden that you’re going to regret, Andrew says.
Buying local also helps reduce the carbon footprint of shipping.
“There’s a hidden cost when you buy something in a bag or bottle. Those products are convenient, but there’s a ripple effect that we may not see right now.”
How Much is Too Much Compost?
Is there such a thing as too much compost in your garden? Andrew says yes.
To avoid overdoing it with compost, get a soil test to find out what’s really going on with soil composition and nutrient levels. We recommend sending soil samples to your local agricultural extension office.
“That gives you a great outlook on the steps you need to take,” Andrew says.
For example, if you apply too much manure, or even too much compost over time, you may find phosphorus levels that are too high, and it might not be the most healthy environment for your plants.”
As a rule of thumb, if you’re amending your soil for the first time, add compost – but not too much!
“It’s always easier to do less and then add more, because you can’t take away what you’ve put in, or tilled in and incorporated, but you can always add more later,” he says.
Andrew suggests beginning with no more than six inches of compost, incorporating it into the native soil of the garden beds.
“Start small, and watch how the plants react,” he says. “Take another soil test at the end of the season, see what’s going on. That would be my recommendation.”
Search for your local extension service office using the Extension Foundation’s custom search tool.
Key Takeaways
- Adding compost to garden beds is one of the most important things you can do for a thriving garden.
- Not all compost is created equal; choose local sources whenever possible or make it yourself.
- Don't overdo it! You can always add compost, but you can't remove it.
- Get a soil test at the beginning and end of each season.
About the Author
Michelle Johnson is an award-winning writer and editor and Baker Creek's unofficial seed historian.
