You have decided to make raised beds and now need to fill them with soil. What is the best soil for raised beds? How often does it need to be replaced? How much compost should be added? Should you mix in some garden soil? I’ll answers these and other question in this post.
Before we start, lets define the term raised beds. I discussed raised beds in Raised Beds – Pros & Cons, and defined them as having walls. I will continue to use this definition in this post.
The common statement “nothing grows under walnut trees” is not true. “Walnuts produce juglone” is not entirely true either. “You need to compost walnut wood chips before using them in the garden” is false. “The allelopathic properties of walnuts are well understood” – not true.
This is a popular subject that is routinely discussed and written about, but the truth around walnut trees is anything but clear.
The tighty whity soil test is a great way to measure soil health and demonstrate the value of no-till gardening.
In this post, I will have a brief look at the science behind the test.
What happens when you add sand to clay soil? Many people claim that this will make concrete and others say that it results in soil that is easier to dig. How can there be such large discrepancies about something that is so easy to test?
Why is this a problem? Gardeners with heavy clay find it difficult to dig, so they want to loosen it up. Sand is very easy to dig and it makes a lot of common sense to add it, to create a looser soil.
Compost tea is all the rage but does it really work? Research studies so far have produced mixed results. The science to support the use of aerated tea on crop plants, lawns, shrubs, or trees is very weak, at best.
There seems to be a lot of work done in this area but much of it is not published in peer reviewed journals and most of it has been done in labs and greenhouses, not in the field. Until the work is repeated in the field we can’t conclude it works in gardens.
The other problem is that controls have been poorly selected. For example, in one study (ref 3) they compared ACT compost tea to water, using lettuce that had been under-fertilized. Guess what, compost tea improved growth. This only proves that adding nutrients, when they are deficient, will improve growth. The study never compared compost tea to adding nutrients in other ways.
In this post I will review one study that compared the use of compost to compost tea, in field conditions.
Mulching the garden is a very common recommendation. Mulch will reduce the number of weeds and it will hold moisture in the soil but how does mulch affect the quality of soil?
There are lots of claims that mulch improves soil but have you ever seen numbers to validate them? I haven’t either. How exactly does mulch improve soil? It should add organic matter, but how much? It should increase the number of microbes, but is this really true? Unfortunately, almost nobody studies landscapes and gardens because no one will fund the work.
Luckily I was able to find one very good research paper that looked at this exact problem.
There is lots of talk about using sterile soil. Some people even sterilize their soil before they use it. Others buy bags of sterile soil. All of this is done in an effort to reduce pests, diseases and sprouting seeds. This all seems to make a lot of sense but there are a couple of basic questions that one should ask;
I’ll deal with the second question in my next post. Today I want to discuss the existence of sterile soil.
You are in the market for some soil or compost and you visit the local nursery or big box store. There are so many products to choose from. Which one is the right one? Should you buy soil, or triple mix, or compost? Or is potting soil the right product to buy?
In this post I will try to sort out this confusion and show you which product to use for different types of jobs.
Go to any garden center and you will find a large range of products that all look like soil. Many names are used including topsoil, triple mix, compost, potting soil, black garden soil, peat moss and garden soil. What is the difference between all of these products? It can be very confusing.
Some of these products are marked as certified. What does that mean? What kind of guarantee do ‘certified’ soil products offer the consumer?
These and more dirty topics will be discussed in this blog post.
Read most organic books or blogs and they will tell you that synthetic chemical fertilizers are killing the bacteria and fungi, the microbes, in soil. Dr. Ingham and her Soil Food Web preach this same message. Stop using fertilizers because they kill the bacteria and fungi. My review of Teaming With Microbes found the same message repeated several times.
Does fertilizers really kill bacteria or fungi in soil?
Some people claim that the ‘salts’ in fertilizer do the damage, but anyone making such a claim does not understand what happens to salts in soil. I’ll explain this in more detail below.
Teaming with Microbes, A Gardeners Guide to the Soil Food Web was reviewed in an earlier post Teaming with Microbes – In-depth Book Review and in Teaming with Microbes – A Close Look, part 1. In this post I’ll look at more content of the book and discuss their validity and the validity of the soil food web. A gardener can learn a lot by looking at these topics in some detail.
Teaming with Microbes, A Gardeners Guide to the Soil Food Web was reviewed in an earlier post Teaming with Microbes – In-depth Book Review. In this post I would like to delve into some of the contents of the book in more detail and provide a different perspective on the soil food web. A gardener can learn a lot by looking at these topics in some detail.
