April 4

Climate and weather

Module 5 of the online permaculture course is all about climate. It’s important because climate helps to refine a design. But how does it do this?

Knowledge of climate can help us:

  • choose the correct techniques, e.g. raised beds or beds dug into the soil that can be flooded
  • choose the right sort of plants and animals
  • choose the right sort of materials to use and whether we want to insulate or build in thermal mass, e.g. greenhouses in cold climates with insulating walls, the amount of ventilation needed in a house.

It is often said that Britain doesn’t have a climate, it has weather. Friends of mine from the centre of France only understood why the British were so interested in the weather when they lived here. In France where they lived, the weather was fairly consistent from day to day and over the seasons. In fact, the weather used to be set for day after day after day whereas here we can have rain, shine, snow and a storm all in one day.

So, what determines climate?  There are seven factors which affect climate: Latitude, ocean currents, elevation, topography, near by water, prevailing wind and vegetation.

Latitude

The nearer to the equator the the more sun  because the sun hits the equator more directly and in a more concentrated manor. The earth is tilted 23.5 degrees on its axis and this means that for half the year the north is tilted towards the sun and then away from the sun (and vice versa for the south) so the rays hit the earth at a different angle and intensity than they do at the equator. The latitude of the equator is 0° and for the Britain 50°  (Cornwall) to 60°  (Shetland Isles). Exmouth is 50.6°N.

Ocean currents

Ocean currents are a very important element for the climate of Britain. As a small island, in comparison with Europe, we are very affected by them. A line drawn from London around the globe would pass through southern Siberia and near Hudson Bay in Canada yet London is much milder in winter. The reason for this is the ocean current, specifically the Gulf Stream which brings warm water from the Caribbean.

Devon has the longest coastline of any region in the UK, having coastline on the north and south of the county.

Elevation

In general, for every 100m that you go up, the temperature drops by 1°. Air is less dense at altitude, the molecules are more dispersed than at sea level. As a result of this the molecules do not bump into each other so much and therefore produce less heat. In Exmouth we are at sea level so there is no reduction in the temperature due altitude.

Topography

Topography is how the geography of the place affects the weather and ultimately the climate. Hills or mountains can create rain and the weather can be different on the windward or leeward side. There can be a funneling of winds due to the shape of the land and a large body of water such as a lake or reservoir can also create milder temperatures.

The west of the UK is higher than the east through plate movements many, many years ago. The prevailing winds are south westerly and this means that there is a lot more rain in the west compared with the east. However, Exmouth is in the rain shadow of Dartmoor as evidenced by the comparison rainfall chart for Princetown on Dartmoor , windward side of the moor and Exmouth (leeward side of the moor). Our rainfall is about half or less of that in Princetown.

J F M A M J J A S
Princetown in mm 219 169 162 109 120 116 112 133 156
Exmouth in mm 88 69 62 63 64 61 59 67 60

We are in a temperate climate with cool, wet winters and warm, wet summers but that is not the same for the whole country. The south east is cold and dry in the winter and warm and dry in the summer. The north west has mild winters and cool summers with heavy rain all year round and the north east has cold winters and warm summers with steady rain all year.

The nearest place to Exmouth with a different climate is Gran Canaria which has a sub tropical climate with hot summers and mild winters and is a place many people from the UK visit in the winter.

The Koppen-Geiger Classification

This is a climate classification system based on the vegetation that grows in a place because plants depend on temperature and precipitation to grow. There are 5 climates – A. tropical, B. Dry, C. Temperate, D. Continental and E. Polar.  These are then divided into sub-categories according to level of precipitation and then the level of heat. The UK is Cfb which is temperate (or ocean), the f stands for no dry season and the b is the temperature of each of four warmest months 10 °C or above but warmest month less than 22 °C. Using maps based on this system from 1901 to 2010 it can be seen that there is an increase in aridity across the world and a decrease in polar regions.

The USDA hardiness zones are used world wide to denote the type of plants that will grow in that region. Most of the UK is zone 8 but here in Exmouth we are in zone 9 meaning that the lowest average temperature is -6.7°C.

The Royal Horticultural Society (RHS) has its own hardiness classification but applies it to plants rather than locations. It works on the theory that we all have microclimates in our gardens and therefore can place a wider range of plants than one overall rate of hardiness might suggest.

March 26

Flow in permaculture

If you know the TV programme The Fast Show, you will be familiar with Jesse and his sayings “This week I have been mostly …” I am looking a bit like Jesse at the moment because I really need my hair cutting and we have very strong winds so

This week I have been mostly looking at flow and pattern!

We have already covered the flow pattern called succession and are now concentrating on the flow of energy in wind, water and I am also going to include people in this because they are relevant to my site. The main focus of our work has been what happens when the flow meets an object – how it moves around it and how that differs depending on the speed or velocity of the flow and applying that to our patch of land.

Because my patch of land is right by the sea, flow has had a very obvious impact on it, creating the dunes in the first place but wind, water and people continue to shape it. It starts at the eastern end at the entrance/exit to a temporary car park which is necessary for the influx of visitors in the summer. The beach, however, is the other side of the road so most people that come out of the carpark need to cross the road and the quickest way to do so is walk up the patch of land to get to the edge of the road. These shortcuts, known as desire lines,  usually show designers where they have got things wrong! They are the paths or flows of least resistance and the land can become quite eroded depending on the number of feet that pass by on them. The path also  doesn’t go straight up or down but comes in at an angle.

It would be quite possible to build a set of steps here that flare out at the bottom, mirroring the erosion but would what happened in this picture happen because we know it is just quicker to walk up. Actually, in this instance I would formalise that path as well so that people have a choice about which to use.

In fact, desire paths are so common, and in some instances so fascinating, that Reddit users document them.

 

I have talked about the wind and the impact it has on this patch of land and some of its edges before but this patch has one difficult, solid edge where a wall and pavement meet. In a southerly blow, the sand hits the wall and drops to the base where one of the road sweepers that keep the beach area looking neat and tidy sweeps up the sand and puts it in his cart to empty it else where I am presuming.  I have often wondered what would happen if they didn’t. Would that paved area fill up eventually and join up with the dune/land at the same level?

Contrary to most edges, I think this is one of those edges that does not increase yield or create a third space that is richer than either side of it.

Are there any lines or paths of desire on walks you do?

March 18

Patterns on a plot of land

We’ve been studying patterns and all of a sudden, they are everywhere. It really is about looking through a filter and although I am not very good at it yet, I am definitely noticing more than I did before.

The plot, outlined in red here, is across the road from the beach and is part of a big pattern of sand dunes created many years ago. From the 1880s onwards the land was used as as a links golf course and some of the bunkers can still be seen.

A road then divided the course from the beach and with pavements and play centres built, the dunes became part of the built environment, parts often becoming separated from each other.

But whilst the sand dunes no longer have access to the sea, they are still building and being blown away in minature on the plot of land.

 

 

 

 

 

 

 

 

The sand dune that constitutes this plot of land is at the end of the yellow dune and the start of the grey dune phase. It is definitely no longer mobile but the main plant growing on it is grass which is stabilising it.

The first pattern obvious when you move down onto the lower pavement is one of a wave alongside the edge where the sand meets the pavement. Whilst edges are some of the most productive places, this one doesn’t seem to be but I think that is probably because people walk on it because the pavement is not wide enough for groups.

 

 

 

In order for sand dunes to be made, you need two media, sand and wind, where the wind  blows sand, deposits it and then blows it away again. In geographic terms, deposition and erosion. Whilst the dunes behind the beach are quite stable, this piece of land has mini dunes on it. The wind blows the sand which gets trapped by the grass on the land and is then eventually blown off, hitting the wall opposite it and deposited at the base of the wall. The ripples in the sand come from the patterns on the base of trainers rather than anything nature has created. Although hard to see, the pattern is again a wave pattern.

Here, the sea beet is moving out from the fence post which offers some protection from the wind in a scatter pattern relating to how the seed has fallen, almost in an explosion pattern.

A book I am reading to gain more knowledge about reading the land is How to Read the Landscape by Patrick Whitefield.

 

 

 

 

 

 

March 14

Using nature’s patterns

In nature there are a limited number of patterns but an infinite number of variations. Take a snowflake: there are no two snowflakes that are the same although they are all formed in a similar way.

The air temperature and the humidity, to some degree, determine the basic shape of the snowflake. We get needle-like crystals at -1.6°C and flat, plate-like crystals at -15°C. The shape of one arm of a snowflake is determined by the atmospheric conditions as it falls; the temperature or humidity might change as it falls and this affects how the water crystal grows and also explains why the six arms are identical. They all experience the same conditions at the same point. Anyway, these patterns are symmetrical and fascinating, so what about others.

In nature we can find waves, lobes, spirals, clouds, branching patterns and scatters all of which are patterns of growth, and nets which are patterns of lateral tension, distribution of weight, storage of energy and shrinkage.

I am going to look at three patterns in a bit more detail: branching patterns, explosion patterns and spirals.

Branching patterns

Orchid flower

Alocasia sanderiana

Cornus controversa ‘Variegata’

 

 

 

 

 

 

With thanks to Meghan Rocktopus

Branching patterns (sometimes called dendritic or fractal patterns) can be one of the easiest patterns to spot. They can be found in leaves, roots, rivers and our circulatory and nervous systems to name but a few places. Looking closely at the three photos taken of plants inside and outside my house, I can see that they have slightly different ways of branching. A little research on the internet suggests that there might be 19 different branching patterns. The Alocasia looks more like a distichous or pinnate branching with the orchid more of a dichotomous branching and the Cornus a trichotomous. This isn’t really important knowledge for permaculture purposes, just of interest to me.

Branching patterns are found where there is a gathering and dispersal of materials or energy. At a micro level they are essential for the efficient exchange of  gases and fluids with the environment due to the maximised surface area.

So how could we use these as permaculture designers? Branching patterns are well-suited to roads and paths where something needs to be distributed across a wide area. Branching patterns can also relate to the organisation of people such as a large, hierarchical company where who line manages who is depicted. For an example of a branching pathway (cervicorn – branching like antlers) used in a permaculture design see p11 of Mobile home garden design by Aranya. Look on the right-hand side of the design next to the decking.

Exploding patterns

Weeds in my garden!

Back to the snowflake patterns which would fit into this category. The image shows two weeds in my garden that both have an exploding pattern in 2d with the leaves lying flat on the ground. You can see how they layer over each other in the weed on the right (I’m not sure what it is called) and in fact it is almost symmetrical with 10 leaves on the lower layer. It is obvious how the arrangement of leaves allows it to gain maximum sunshine and I do wonder if it does well in slightly shady spots where this photo was taken. There is a very direct route between the central point and each external point  in complete contrast to a spiral where the central point is a long way away from the end point if you follow the spiral around.

This explosion, however, is the dried flower of Allium x ‘Globemaster’ with some seeds left in the seedheads. The flowerhead is made up of hundreds of little flowers in a beautiful purple during late May early June.  It is an excellent example of a pattern within a pattern within a pattern because it is an explosion making a sphere with some branching at the end of each individual flowerhead. You get a really clear picture of how the seeds are dispersed all around the plant, some near and some slightly further away.

 

Some towns and cities have an explosion pattern built up over time. They may well have started off as a nucleated settlement but then have grown over time, spread out along main roads finishing with some isolated housing which eventually becomes part of the main settlement. Lisbon is one city that shows an explosion pattern of settlement.

 

So, how can we use this pattern in design? This is an image of La Ferme du Bec Hellouin in Normandy, France. Below the polytunnels can clearly be seen an exploding pattern set of beds all coming off a central point. Often in walled gardens there would be a well or water store in the centre of this type of pattern, making it quicker and easier to water the beds – or nowadays a tap on a standpipe from a gravity-fed reservoir on higher land. This link gives a closer view of the bed.

And finally, spiral patterns.

These are another type of fractal pattern frequently demonstrated through a snail shell, sunflower head, climbing tendrils on sweet peas and in weather systems.

Euphorbia myrsinites

 

 

 

 

 

 

 

The euphorbia above has a spiral in a spiral. First the leaves spiral around each stem and then each stem spirals out of a central point. I did wonder if the whole plant was an example of an explosion but the stems curl round rather than being straight so I am putting it in the spiral group, not unlike weather patterns. The spiral arrangement of leaves on a plant is to ensure maximum exposure to sunlight and for the seeds. Spirals are able to capture and slow down energy such as in a herb spiral, that ubiquitous permaculture plant bed. To be fair, they are space-saving and allow for different types of herb to be grown, making use of the different amounts of moisture in different parts of the bed.

 

Photo from Olds College, Flickr

https://www.tomatocages.org/tomatocage/tomato-spirals.html

 

 

 

 

 

 

 

So how else can we use spirals?

I have a number of spiral plant supports which I use for tomatoes in particular. They are tall, narrow spirals which you can twist the stems around as they grow. But there are also other spirals that can be used as plant supports. The third image shows a support that allows climbers to go up and the final one supports flower heads. I use one of these on a peony.

A vortex is a spiral where the air or water swirls around and anything caught in the motion is pulled into the centre. One place where this can be used in the garden is in free flow water features to aerate the water. They are based on an idea from Rudolf Steiner and shown through Drop Test Pictures developed by Theodore Schwenk. Water moves in patterns down a river and creates patterns when a drop is released. Pollution in the water will change the patterns formed so tap water gives a different and lower quality pattern to water fresh from an unpolluted stream. The free form fountains mix water and oxygen together providing support for organisms to break down pollutants and is reported to increase and stimulate plant growth.

Do you use any patterns from nature in your garden?

A book I have bought to read as a result of this module on patterns in nature is Patterns in Nature: Why the natural world looks the way it does by Philip Ball.

March 5

What’s in the local environment – permaculture activity

Having finally decided on the space for my online Permaculture Design Course activities, today on my walk I focused on the plants, including the big trees that I missed.

I have already mentioned the grass that is growing on the land which is doing a sterling job of preventing erosion and stabilising the soil but there are a couple of other things as well.

 

 

The first plant is yarrow, Achillea millefolium, wrapped around one of the fence posts at the west end of the land. The picture of it demonstrates how it creates more soil as the leaves that blow around and get caught in it rot down along with the plant stems. The Wildlife Trust website states that this is a plant that can help to restore arable land to grassland which it is doing here as well as stabilising the soil.

This next plant I am less sure about.

Again, its clumping form helps trap soil/sand, leaves etc. At first I thought it was a crambe which edible seaside plants but the leaves don’t look quite as kale like as most crambes do.  I wondered about dock, it looks like horse radish that has gone wild on the allotment next to mine. As there are no flowers it is hard to say. However, after using PlantNet I think I agree with them that it is Sea Beet, and edible coastal plant.  I will be more secure with the identification when it flowers.

On the other side of the road around the new development, there has been some planting and I thought it might be worthwhile noting what has been put in and look at how they do over time – you never know. There might be something that would do well on the bit of land I am looking at.

 

 

 

 

 

 

 

 

 

 

First we have a cistus and what I think is a cotton lavender, Santolina chamaecyparissus. I’ll be able to tell more when they flower but here the landscapers have dipped into Mediterranean plants. They are planted someway behind the buildings and so are probably somewhat sheltered from the southerly winds. The santolina can be used to create low hedges and that might be useful on my plot to trap leaves etc to build up the soil.

 

 

 

 

 

 

 

 

 

 

There is also an eleagnus and a sisyrinchium which likes hot, dry conditions but will also tolerate some shade and damp and our winters are damp.

One plant has already died – probably the Beast from the East saw if off with desiccating, cold winds. It was some sort of fastigiate small tree – yew/pine.

It is still behind the buildings but at the edge and probably is just not protected enough.

As more plants appear, I will add them to this list.