Tuesday, 3 January 2012

Using 'Sheep Power' to Mow and Fertilise the Lawn

Of late we’ve had quite a bit of rain resulting in rapid growth of the grass in the house yard. One of our mobs of sheep was in the front paddock as part of our grazing plan. Given that the weather is quite hot at the moment we decided to let the mob of over 400 sheep into the house yard to eat down the grass a bit and to do a tad of natural fertilization.

Here you can see some of the mob in the northern section of the yard.

This photo shows some of the sheep in the eastern part of the yard.

Yes, they did stir up a little bit of dust in the process but this was not an issue at all. See below.

To prepare for the sheep coming into the yard we moved some potted plants up out of the reach of the sheep and covered with mesh guards those we definitely did not want eaten.

It was difficult to assess how long the sheep should stay in the yard before bringing them in. To be safe we decided to 'stand guard' and let them out when we felt they'd taken enough of the herbage mass. The total duration ended up being approximately half an hour.

One unforeseen bonus of the sheep being in the yard was that they did an excellent job 'trimming the edges' and eating under things in the yard (like the trampoline) that we'd normally need to move if using the mower.

Here's a range of 'before' and 'after' photos. Not a bad effort, we think, especially given the whole process took less time than conventional mowing ... and a lot less energy.

Location 1 - Before

Location 1 - After
The hose is more visible and the flowers of the Patterson's Curse plants have been eaten.

Location 2 - Before

Location 2 - After

Location 3 - Before
Location 3 - After

Location 4 - Before

Location 4 - After

(Sorry ... this photo from a comparison perspective is a bit tough to judge ... it was taken on dusk).

We learned during the process that in addition to grass the sheep loved eating the following plants in the house yard:
  • Peach and apricot trees
  • Lilac tree
  • Grape vine

On the other hand none of the sheep touched any of the following plants in the house yard:
  • Geraniums
  • Heliotrope
  • Pumpkin
  • Cassinia
  • Nodding Blue Lilly
  • Lemon Tree
  • Smoke bush
We thought it was pretty neat that (as you will see in the following photograph) the sheep ate the weeds around one of the potted geraniums but left the geranium alone.

Given the success of the exercise we think we'll do a repeat each time we have a largish mob of sheep in the Front Paddock.

Monday, 2 January 2012

Sourcing and Installing Sundials

We were delighted to receive a sundial as a gift for Christmas. We’d been keen on having for quite a while as both a tool to use for telling the time naturally and as a garden feature.

Our thinking was that a sundial would be a simple process to source and install, but not so as it turns out. We contacted Larry Varley who lives in Victoria and makes both sundials and weathervanes (http://www.acmefluid.com.au/larry/weathervane.html) for some answers to a few questions we had. Some of the comments that follow come mainly from the conversation we had with Larry.

The two components of a sundial are the sundial itself (or base-plate) and the 'style' which is the thing that stands up from the sundial and casts the shadow.

Most sundials are made in India. These are not expensive, but the catch is that they most are made for the northern hemisphere. If these are installed in Australia they are useless aside from midday for telling the time.

The sundial should be installed on a level surface in a place where it will be in direct sunlight for most of the day. In our case, we decided to relocate and use the old base 'milk and cream separator' base that the Causer family installed when they lived here during the period 1950-1965. We’ve positioned the base to the north of the house near the verandah. It will be a great location for it now that the large tree that used to be near the car shed has been removed. This photo shows the base with the sundial sitting on top of it.

The style needs to also be pointing toward true north. It is a simple process to loosen the screw on the underside of the sundial, turn the style to get it pointing to the ‘north’ indicator on the sundial, and retighten the screw.

The sundial needs to be oriented to ‘true’ (rather than magnetic) north. Here’s a few website links that give some important explanations:

2. Geoscience Australia – Calculator - Australian Geomagnetic Reference Field Values - http://www.ga.gov.au/oracle/geomag/agrfform.jsp

Using point 2 above it turns out the variation we need to use is 11.357 degrees.


For absolute accuracy the angle of the style should be equal to the latitude of the location. We checked ours and found the angle to be 37.5 degrees, meaning that it has been manufactured for use on latitudes about the same as the city of Melbourne. We are located about 33.5 degrees south so won’t get absolutely accurate time unless we purchase a new style. It may well be that the gradations on the sundial vary according to latitude as well.


As a general rule with sundials it is unlikely that the time on one’s watch will align precisely with the time on the dial. This is because of the way time zones are in place globally. Our area of Australia is such that we fall within Australian Eastern Standard Time (AEST) during the cooler period of the year and Australian Eastern Daylight Time (AEDT) during the warmer part of the year. AEST is set at 10 hours ahead of Coordinated Universal Time (UTC) and AEDT is 11 hours ahead of UTC. It gets tricky to figure out what the time should be on the sundial because each time zone applies to a range of degrees of longitude simultaneously i.e. each location that is within the same time zone regardless of its specific longitude uses the same time while the position of the sun relative to the sundial changes constantly.


It is something of a brain-teaser exercise to work through the various aspects of how time is calculated. Here are some bits and pieces that have come out of our research (NB: Some figures are approximate only):

·         The circumference of the Earth is 40,075.16 km

·         A full circle is divided into 360 degrees

·         It takes 24 hours for the Earth to do a full revolution

·         During each hour the Earth rotates 15 degrees

·         Given there are 60 minutes in 1 hour the Earth rotates through 1 degree every 4 minutes

·         The speed of the surface of the Earth based on circumference and daily revolving calculates at approximately 1,670 km / hour

·         We are located 148 degrees east of Greenwich

·         We are thus technically 9 hours 52 minutes ahead of the true time at Greenwich at any moment in time

·         The rotation of the Earth is slowly declining.


What we’ve concluded from all of the above is that understanding the various aspects of sundials is far from simple. The moral of the story also is that if you want your sundial to be very accurate then you should buy one made locally from someone who has the ability to customise components to suit your location.