To mulch or not to mulch, that is the question!
Post categories: seasonal tips
| 10:30 UK time, Monday, 21 March 2011
We have had a better week, snow threatened but stayed on the higher ground, some days the sun shone brightly but there is still a cold wind. As a result, thankfully the ground is beginning to dry out.
Seaweed used as a mulch in Torosay Castle Garden, Isle of Mull
One of my priorities is to order up some bark to mulch two new borders primarily planted with shrubs and trees. Ground cover that doesn't need cutting every week is what I am aiming for coupled with all year round interest! At the moment, the plants themselves are not big enough to provide that cover, hence mulching is vital. Bare soil is bad - except in winter when it has been freshly dug over and left to 'weather', which I would describe as a natural conditioning process.
Mulching raises the old argument - yes or no? If not, why not? If yes, with what? The first good reason for doing it is to cut down weeding and the second is to help condition the soil by slowly adding more organic material. There are still some spaces to be planted in my new borders, but that is a gradual process so the imperative is to get the ground covered.
I will use bark but some of my associates and colleagues are not so keen. Several years ago, on a question time session at as I recall, a rose-grower of my acquaintance took me to task for suggesting the use of bark to mulch roses. In his view it was likely to be counter-productive in that the roses would suffer and become less thrifty. I do agree, I have seen that happen. Why should that be? As we all know, bark does take a long time to decompose and the bacteria that aid the process are said to rob the soil of plant nutrients. I can't dispute that claim and wouldn't necessarily want to, my job is to explain that you must compensate for that eventuality.
My spring drill in this regard is to scrape the remainder of last year's mulch away from around the plants, apply some organic fertiliser - sometimes I use pelletted chicken manure, sometimes bone meal and this year it will be fish, blood and bone! This is pricked in to the surface using a border fork then the mulch is replaced, replenishing with fresh material if necessary.
What are the alternatives? By its very nature, mulching material is quite bulky, it is applied by the forkful not the handful so availability and distance from source is a financial consideration for many. For example we have a source of spent mushroom compost a few miles away and therefore we certainly use plenty of it in our borders at the .
Spent mushroom compost, has been through two composting processes by the time it becomes available to the gardener - the initial composting to turn it into a growing medium for mushroom production and then that very production process which requires comparatively high temperatures and plenty water. The spent material is admirable as a soil ameliorant, forked in to the surface layers, or as a mulch. Be aware, it has a mild liming effect.
Other alternatives that come to mind are where appropriate and well rotted farmyard manure but that is not so easily come by for town dwellers unless they can afford to buy the bagged stuff courier delivered products or from garden centres.
How much will you need?
Taking bark as an example, it is not going to be much of a weed suppressant at less than 50mm deep, which means that a cubic metre will cover 20 square metres. How much ground will be covered by an 80 litre bag of the stuff - 'not a lot' as the TV magician used to say.
Comment number 1.
At 21st Mar 2011, hereisabee wrote:Plants unlike animals, thrive in their own waste. This is certainly true for bamboo whose leaves are rich in silica. So there is theory that says we should not be too neat and tidy in the first place. From that the perfect mulch is always going to be your own garden compost? Narrow borders need fine mulches, as otherwise the blackbirds will flick the pieces of bark all over the lawn or path, in their relentless search for a worm.
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Comment number 2.
At 21st Mar 2011, miriamriverside wrote:Do you put the trace element fertilizer under the mulch or over the top? I do not have access to damp seaweed.
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Comment number 3.
At 23rd Mar 2011, Jim McColl wrote:@ hereisabee
When you think about it, mulching is really copying what happens in nature - the deciduous foliage falls in the autumn and just lies there. As it breaks down naturally, it is pulled into the soil by worms whilst offering shelter and succour to other animal life.
In many large gardens that is still part of the management strategy but in small suburban gardens, many will choose to collect the detritus and compost it.
This compost is better to be dug in to the soil when it has decayed to a friable consistency, meanwhile something like bark, which is arguably more pleasing to the eye, is used to suppress weeds and conserve moisture.
I agree entirely that the blackbird population do make a nuisance of themselves by throwing stuff on to grass and paths. I don't have an answer to that but someone else may!
@ miriamriverside
I agree that not everyone is able to use seaweed for the very practical reason that they don't live anywhere near a beach! So far as trace elements are concerned, they tend to be naturally available in organic fertilisers and as I say the annual spring dressing should be applied and forked in to the soil lightly BEFORE replacing the mulch on top.
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