Tag Archives: garden mulch

Tikorangi notes: narcissi, garden edgings and a happy plant breeder

The snowdrop season is all but over already. It is charming but brief. The narcissi, however, have a longer season, at least in part because we can grow a much wider range of species and hybrids. Yesterday felt like a winter’s day – the last gasp of winter, I hope – so I headed out to pick one each of the many different varieties in flower. We don’t grow many of the larger ones at all, preferring the charm of the littlies, the dwarf ones. Bigger may be better when it comes to magnolias – at least in our eyes – but daintiness wins with the narcissi. Most of these are named varieties though Mark is also raising cyclamineus seedlings to build up numbers for planting out and to get some seedling variation within them. The cyclamineus are the ones where the petal skirt sweeps back, sometimes completely reflexed, giving them a slightly startled appearance. He was intending to plant many of these down in the park but hadn’t got around to it so offered them to me for the new grass garden.

Drifting dwarf narcissi through the new grass garden. Camellia Fairy Blush hedge and Fairy Magnolia White edge the garden on both long sides. 

I have now compromised the big, bold, chunky planting in waves that is the hallmark of the new grass gardens by drifting hundreds of dainty, dwarf narcissi through them – though far enough out to escape being swamped by the large plants, for several years at least. It adds seasonal interest to an area that will not come alive again until later in spring.

Informal bark edging and bark and leaf mulch define the garden area

After much consideration as to how we wanted to complete the grass garden with regard to edging, mulch and path surfaces, we have gone for the casual, organic and local options. As soon as I started to load in the wood and leaf mulch that a local arborist delivered, I realised that the beds would need an edging to hold the mulch from spilling over. My idea of a seamless transition between bed and path was not going to work. We have pine bark to hand – left over from getting the firewood out from a fallen pine tree so I am constructing small edges out of that. It lasts for many years. The paths are still bare earth (we will probably use granulated bark on those) but as soon as I made the edgings and laid the mulch, it took on the appearance of a garden. It is a casual look but one that sits easily with us with the benefit of being low cost and, as Mark keeps saying, the use of organic materials adds carbon to the soils.

I am laying the mulch on fairly thickly – around a forefinger in depth which I measured to be about 7cm. Because it is fluffy, it will compact to less than that but if I see any weeds coming through, I can top it up.

Fairy Magnolia White – not only a beautiful flower form but a very long flowering season, beautiful velvety buds, good foliage and perfume

Mark is a quiet man, not given to blowing his own trumpet, but sometimes I hear him murmur a comment of deep contentment at a plant he has bred and named. So it was this week as we looked at the avenue of Fairy Magnolia White and Camellia Fairy Blush. “I picked White because it had a pretty flower,” he said. And it does. In a world of floppy white and cream M. doltsopa flowers, Fairy Magnolia White stands out with its beautiful star form. There were a lot of very similar sister seedlings to choose from in that cross and as a breeder, he always worries whether he picked the best one. I think he finally decided that he had indeed chosen the best which is just as well, when you think about it, because he will only ever name and release one of that cross

Camellia Fairy Blush also has a long flowering season, drops its spent flowers cleanly and clips well

Camellia Fairy Blush, planted as a hedge beneath the two avenues of Fairy Magnolia White, is also a continuing source of satisfaction and delight to us, even if it is a constant reminder of a missed commercial opportunity. It was the first camellia he ever named and sold. Back in those days, protecting a plant as our intellectual property was not even on the radar and now Fairy Blush is sold widely throughout the world and few know that it originated here and was Mark’s selection. We have even seen it branded overseas with other nursery names but we know it is ours. That is life and it is a very good camellia and continues to be a source of pride and pleasure to the breeder.

Fairy Magnolia White and a very blue spring sky

The merits of mulch

Homemade compost - our preferred garden mulch

Homemade compost – our preferred garden mulch

Mulch, dear readers, mulch now. Mulch well and you will be grateful later.

There are good reasons to mulch. In areas prone to drying out over summer, a good layer of mulch put on now will contribute to retaining soil moisture levels later. You don’t want to be mulching when the soils have already dried out because, equally, it acts as a barrier to stop water being absorbed.

Mulching also keeps down weeds and hugely reduces the amount of summer weeding that is required. There are two provisos. You need to clear the area of weeds first. Mulch won’t kill existing weeds. It just discourages germination of all those seeds lurking in the soil waiting to spring forth when the time is right. It also makes it much easier to pull out those that do penetrate through the layer. The second proviso is that you need to be using a weed-free mulch and many home compost mixes won’t have achieved that state.

Avoiding soil splash is another benefit. In areas of heavy rainfall (and some of us can get downpours akin to the tropics, albeit without the warm temperatures), bare soil splashes back up and this can spread disease amongst vulnerable plants. Soil splash also makes vegetables dirty. Mulch acts as a cushioning filter.

Depending on your choice of mulch, it can act as a soil conditioner and add valuable carbon content. Some will gradually break down as worm and microbial action incorporated it into the soil. Obviously this is only true for organic matter. We are big fans of organic mulches here, less so of inorganic options like limestone chip or gravel. But no matter what you use, a mulched garden looks better than expanses of bare soil. It is the experienced gardener’s not-so-secret weapon. You won’t find many good gardeners who do not mulch regularly.

So what to mulch with? Our number one preferred option is compost, homemade compost in fact. It does three jobs in one hit. It mulches, it feeds the soil so that we rarely have to use other fertilisers and it looks unobtrusive. But then we do not want a mulch that looks obvious. It is a tool, not a display in itself.

Leaf litter can be untidy but makes a good mulch

Leaf litter can be untidy but makes a good mulch

The second choice mulch here is leaf litter. We don’t waste any organic material. If it doesn’t get composted, then it gets raked into a back area to gently decompose and darken, before being raked back out around plants. Leaf litter can be untidy but it is good in less formal areas.

Then there is fresh wood chip. We own a good sized mulcher so we generate a fair amount of wood chip from the garden debris that is too large to go into compost. Calf shed shavings and sawdust also come into this category. When fresh, all these materials have to be used as mulch but not dug into the soil or they will rob the nitrogen as they break down. Laid on top and exposed to the elements, the decomposition happens slowly and naturally and should not cause problems. If you are going to use sawdust, just make sure that it is never, ever tanalised (you will poison your soils) and be prepared for a few months of a somewhat alarming orange appearance.

Old wool carpet and newspaper (weight the latter down) can be used as mulch if you don’t mind the look. We do mind, so we don’t go down that track. Just make sure the carpet is 100% wool and not synthetic and keep to newspaper – leave the glossies out with the recycling.

Pea straw may be a better option for the vegetable garden than the ornamental garden

Pea straw may be a better option for the vegetable garden than the ornamental garden

If you need to head off to the garden centre to buy your mulch, you will often find pea straw on offer. While this is a traditional mulch, if you are not in a pea producing area, consider its carbon footprint. It blows away unless you keep it damp. It is a myth that it helps fix nitrogen in the soil – that capacity is in the pea roots and all you are buying are the tops. Aesthetically, I think it looks fine in the vegetable garden (especially if it is all around high-producing strawberry plants) but I am less keen on the look in ornamental gardens. A bale should cover around 6 square metres of area.

Granulated pine bark is often favoured. Try and get it pre-composted. Compounds in the bark stop it rotting down too quickly so it lasts a surprisingly long time on top. It is a discreet looking mulch but it adds no fertility. If you have a big area to cover, buying it in bulk will save money. A cubic metre should cover around 15 square metres.

You need a layer of 6 to 7 centimetres to be effective. You will often see 10 cm recommended but that is pretty deep. Finally, try not to pile the mulch hard in on the trunks of woody plants. It doesn’t matter around perennials but trees and shrubs run the risk of collar rot.

The mulching effort now will reward you further down the track.

First published in the Waikato Times and reprinted here with their permission.

Garden lore

“… the truly formal garden is all about showing off your ability to groom and control. The more attention you pay to detail and maintenance, the better your garden will look, so don’t go there if you take a casual approach to chores. Consider rethinking the way you mow. The perfectionist will always mow lawns in straight lines parallel to the main axis.”

Xanthe White , NZ Gardener (May 2013).

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Pine bark
Pine trees produce a prodigious amount of loose bark and given the number of pine trees we grow in this country, pine bark has become a garden staple. Ground up and composted, it is now the major source of potting mix. As a renewable resource, it has done a great deal to save the peat and sphagnum bogs formerly raided for this purpose. Chipped to various grades, it is widely used as garden mulch. But, you need to understand that the reason pine bark is so useful is because it is remarkably inert and stable. It takes years to rot down so it does next to nothing to condition the soil even though it is an organic product. When a whole branch or trunk is chipped or mulched, it will break down quickly and add carbon content, but not straight bark.

So stable is pine bark that we use large flakes from our trees as an informal garden edging, stacked as you might stack thin pieces of old concrete. It lasts for years. If you are buying bark mulch, the mixes of bark and pine fibre will look more natural (and the fibre will break down faster, adding some nutrient to the soils). The chunkier bark nuggets look a little… clunky but will last for ages. The finer screened bark mulches will look smart in that urban landscaped look but can wash away in heavy rains. I have not seen the horror of died bark mulches that are favoured in Australia. Don’t go there. Your garden will not look better for being mulched in red, tan, blue or green pine bark.

First published in the Waikato Times and reprinted here with their permission.

Garden lore

Don’t wait until January to batten down the hatches for summer. As you do the spring tidy and weed, follow up by laying mulch. This slows the soil from drying out over summer and suppresses many weeds from germinating. A loose layer of compost, bark chip, calf shed shavings or similar organic material needs to be about 6cm deep in order to be effective. For more information on garden mulches, check out Outdoor Classroom.

“Hoeing: a manual method of severing roots from stems of newly planted flowers and vegetables.”

Henry Beard (American humourist).