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Archive for the Research Study Category

Compost Tea – Does it Work?

Compost tea is all the rage but does it really work? Research studies so far have produced mixed results. A 2007 meta data review on compost tea by Dr. Linda Chalker-Scott concluded that “Clearly, the science is not strong for aerated tea use on crop plants, much less on lawns, shrubs, and trees”.

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.

Effects of compost tea on the growth of trees, by Garden Myths (data from reference 2)

Effects of compost tea on the growth of trees, by Garden Myths (data from reference 2)

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Mulch – How Does It Affect Soil?

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.

Effect of fertilizer and mulch on soil, by Garden Myths (based on reference 1)

Effect of fertilizer and mulch on soil, by Garden Myths (based on reference 1)

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Eggshells – Decomposition After One Year

A year ago I started a study to see if eggshells decompose in soil; Eggshells – Decomposition Study. It is now one year later and time to have a look at the buried eggshells.

eggshell decomposition study - year 1

Eggshell decomposition study – year 1

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Orchids – Do They Need Water?

More orchids are killed by over watering than for any other reason. It begs the question, how much water do they really need? How long can an orchid go without water?

I know they grow slowly and react slowly to their environment. They also die slowly. I decided to see if an orchid needs to be watered regularly.

Orchid without water - day 1, by Robert Pavlis

Orchid without water – day 1, by Robert Pavlis

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Styrofoam Cones – Do They Keep Roses Warm in Winter?

As winter approaches, we worry about our poor plants making it through the cold. All manor of wrapping devices are used to protect them and Styrofoam cones, also called rose cones, have become popular in recent years. Do these contraptions work? If they do, how much warmer do they keep your plants?

There is a lot of talk on the internet about Styrofoam cones. Many extension offices recommend them, and suppliers certainly tell you they work, but I was unable to find a single source of information that actually provided data to support the idea that Styrofoam cones keep plants warmer in winter.

So I decided to do some testing of my own.

Temperature changes with and without a Styrofoam Cone, by GardenMyths.com

Temperature changes with and without a Styrofoam Cone, by GardenMyths.com

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