It is August – time for magnolias, laying paths and killing moss

Magnolia campbellii ssp mollicomata ‘Lanarth’

Lanarth down by the water in our park

As August arrives, there is so much happening in the garden. Every day sees something else in bloom and now I get anxious that if I forget to look for a few days, I might miss something. I tell you, spring can be stressful.

Mark’s yellow Lachenalia reflexa hybrid

But our thoughts go out to overseas readers whose lives continue to be disrupted, discombobulated and sometimes turned upside down by Covid-19. Never has New Zealand felt so comfortably remote and self-contained, a small cluster of islands holding the unpredictable forces of chaos at bay, so far. May you stay safe and well, wherever in the world you are.

We are inching ever closer to finishing the new summer gardens, or at least to completing this stage of development. There are just the path surfaces to be laid and that has to wait until the man I hope can deliver the materials and arrange a bob-cat returns from holiday next week. We solved the problem at one end where the steps down to the garden were at a lower level than the camellia and michelia hedge that forms the backdrop. It was always going to involve some means of separating the levels. We priced steel edging because I really like that au naturelle, unobtrusive, thin look of gently rusted steel. Buying the branded product specifically designed for garden edging was very expensive indeed and that was without factoring in freight. Ever-handy Lloyd priced buying the steel locally, cut to suitable size, and it came in at about a third of the price but still somewhere over $1000. It was not going to bring me enough pleasure to warrant spending that amount of money.

Compromising with a stained timber edging

Much and all as I dislike tanalised timber in the garden, I compromised and said that would be okay as long as we stained all bits that will be visible to charcoal black. It was a solution that cost $103 (to buy six metre lengths of timber) and once the paths are laid, I do not think it will be obvious at all. The paths will be built up by about eight centimetres so there will not be a whole lot left visible.

A handy bobcat back when we started work on these gardens

Because it is going to take up to 30 cubic metres to lay all the paths, our plan – subject to the advice from the man currently on holiday – is to lay a base core of pit metal compacted to about 3 or 4cm deep and then lay the crushed, creamy yellow limestone on top of that to another 4cm. We think the pit metal will be much cheaper than limestone. We need to hire a bobcat and operator because none of us want to be carting 30 cubic metres of anything and the bobcat will be able to do a lot of the compacting that is necessary. If you have never seen a bobcat operating, believe me they are fast, manoeuvrable and quite mesmerising to watch.

On another practical level, a packet of Cold Water Surf washing powder entered my life. I had forgotten about its existence. It is vile, over-scented stuff that I would never use in the laundry but others may not mind that overpowering scent of chemical fragrance. We use unscented washing powder in this household of sensitive skins. But damn, that Cold Water Surf is a whizz on killing moss.

People in drier climates will not relate to the issues of excessive moss and lichen growth that we get here. There is nothing wrong with some, but we can get way too much. Sometimes we water blast (jet wash) the paths but that also takes off the surface of the concrete and flushes out any filling between pavers. It is just as fast for me to scrape off the top layer of moss, sprinkle Cold Water Surf to kill what remains and then use a stiff broom to sweep the residue off.

And it can kill very fast. This rather deep-rooted moss browned off within hours and died soon after.

I am no chemist so I struggle to get a grip on the difference between carbonate, bicarbonate and percarbonate. But as far as I can see, the active ingredients in many of the expensive, branded moss killers are often sodium carbonate (washing soda or soda ash), or sometimes sodium percarbonate (which is washing soda and hydrogen peroxide – a common ingredient in eco-friendly bleaches and other cleaning products).

You can buy both sodium carbonate and sodium percarbonate in powder form and I have done so but it worked out relatively expensive to use in the garden when cheap Cold Water Surf works just as well. Logically, this must mean that I was spreading the pure product too thickly when it can be extended by adding some sort of neutral carrier (Mark suggested sand). At a practical level, the products were fine powder and the coarser texture of the laundry powder makes it easier to spread evenly. Also, logically, any proprietary laundry powder should work unless some have a higher percentage of washing soda than others and that I do not know.

I am wondering whether it will work on our sandy coloured pavers in our front entrance courtyard. I water blasted these a few years ago. It was my first ever go on the water blaster and it took a lot longer than I thought it would. It was also wet and messy and blew out the sand between the pavers which Lloyd than had to refill. But they looked like new when done. Now they are blackened and discoloured again. I know there are branded products that attach to the hose that will also work and are quicker to use, albeit expensive. If laundry powder will do it, that appeals to my economical nature and avoids buying another product sold in a hard plastic container. I shall experiment and report further.

Narcissus Peeping Tom

9 thoughts on “It is August – time for magnolias, laying paths and killing moss

  1. robynkiltygardensnz

    Sounds like spring is really burgeoning in Taranaki Abbie. Not here in Christchurch yet, although the green shoots of bulb -i.e. tulips are poking through the ground, and a few underwhelming Snowflakes (leucojeum) but I haven’t seen a decent Magnolia out here yet! Not like your beauties!!
    A great tip for moss though – will try it on my bricks.
    I don’t know my replies to your posts ever reach you?? As I do reply to most of them.
    If not – what am I doing wrong??

    1. Abbie Jury Post author

      Very much spring here, Robyn. And 17 degrees today so that was pleasant. I see the first Dutch iris open and the leucojjms and galanthus are already starting to pass over.
      Usually, if your comment comes through, I reply to it.

  2. Tim Dutton

    As we average over 1900 mms of rainfall in a year in our garden, we were very interested to hear about your experiments with washing powder on the moss. I’ve been using iron sulphate to kill moss for years now, dissolving it in water in a can and then watering the patches of moss on the paths and driveway. The moss turns black almost immediately. The trouble with iron sulphate is that if you water moss on paving slabs it blackens those too, so the thought that we might be able to use Surf in the cracks between the slabs without staining them is intriguing. One good thing about the iron sulphate is that you can also use it to kill moss in lawns as it doesn’t harm the grass, in fact it seems to boost its growth and makes it greener than ever, though of course you have black moss patches for a while before the grass takes over again. I doubt that Surf could be used on moss patches in a lawn without killing everything else.

    1. Abbie Jury Post author

      No, Surf is fine on the lawn. That was what it was first recommended to me for. I am experimenting with it on hard pavers now but I suspect one of those wet and forget products may be better for hard surfaces. I figure that any product that is safe for a septic tank is probably okay when diluted in the environment.

  3. Paddy Tobin

    You are truly putting a huge amount of work into preparing the garden for the coming festival and it will look wonderful.

    Moss is a perennial nuisance here in Ireland also and I have read of using washing powder to eradicate it, at least temporarily for moss is frightfully persistent. It is something I may try next winter/spring.

    ‘Lanarth’ is one of the beautiful things of this world, an absolute treasure.

    1. Abbie Jury Post author

      Best foot forward, Paddy! At least when it comes to opening the garden. Washing powder works best on moss in the lawn, in my experience. Not that we worry much about a mossy lawn but I am not keen on the bigger, coarser mosses.
      Lanarth is indeed glorious. A short season because it flowers on the tips only but beautiful while it lasts.

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