Garden Myths - Learn the truth about gardening

Archive for the Research Study Category

Does Peat Moss Acidify Soil?

Some very desirable plants like rhododendrons, azaleas and blueberries demand acidic soil and many gardeners have alkaline soil which is not suitable to grow these plants. The most common solution I’ve seen is to mix peat moss with the soil to produce an acidic environment.

Peat moss is acidic so it makes sense that if you add some to your soil, the resulting soil will also be more acidic. But is this really true? How long does the acidity last? Can gardeners with alkaline soil use peat moss to grow rhododendrons, azaleas and blueberries?

Does peat moss change soil pH?

Does peat moss change soil pH?

—————- Read More —————-

If you like this post, please share .......

Planting garlic – When Is The Right Time?

The recommended time for planting garlic in colder climates is mid-fall – October in zone 5. That certainly works but is that the best time?

Spring bulbs, like tulips, are also planted in fall but common advice for these is to plant them as soon as you get them. Earlier is certainly better than later. Planting earlier allows the bulb more time to develop a good root system before winter sets in. Since garlic is a bulb, would the same logic not apply to it? Would it not be better to plant garlic sooner?

Planting garlic - When Is The Right Time? From left to right, Aug 2, Sept 1, Oct 1, by Robert Pavlis

Planting garlic – When Is The Right Time? From left to right, Aug 2, Sept 1, Oct 1, by Robert Pavlis

—————- Read More —————-

If you like this post, please share .......

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, in field conditions.

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)

—————- Read More —————-

If you like this post, please share .......

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)

—————- Read More —————-

If you like this post, please share .......

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

—————- Read More —————-

If you like this post, please share .......