Term 4 – Week 3 – Irrigation Installation


View of orchards using a water race and dams to get water

The new frost fighting irrigation system for the young apricot trees was installed this week. The system is constructed from PVC pipes underground, steel uprights and overhead impact sprinklers.


Team leader Bruce sizing up the job

Luckily for us students a digger dug out all the trenches for the new pipes. We just had to hand dig more carefully around the existing pipes.

The pipes were laid and joined up using a primer and PVC glue. The primer is important as it etches and cleans the pipe before gluing. Twist the fitting a half turn to smear the glue evenly. Hold firmly for about 90 seconds for it to set. It will take at least an hour to dry, up to 24 hours to dry fully.


Primer application

Once everything was dry the water was turned on to check for leaks and to flush out any gravel or grit that had gotten into the pipes. The first sprinklers at the start of the system were added to the top of the uprights after the initial flush and then flushed again. Then the same again for the next section. This is because the water pressure is strongest at the start of the system and adding the sprinklers moves the pressure down the system, flushing out anymore dirt that was stuck in the corners of the pipes.


Frost fighting impact sprinklers in action

Also this week I got to have my first go on the Hydralada. The controls to move it are all under your feet (which can be a problem if you lose your balance!), push your toes down to go forward, heels to go back, left toe to turn right, right toe to turn left etc. There is another control in the middle of your feet that moves the ladder up and down. It feels much higher than it looks when you are up there! It’s really stable though, and you can still keep driving it from up in the air.


Learning to use the Hydralada

Last week’s weather:



Term 4 – Week 2 -Bits and pieces


The peonies have started to bloom here at central campus – how gorgeous! I can’t wait to see them all out.

This week there were a few odd jobs to be done.


Adding fertiliser to the young cherry trees. Bottom left: Chaman

Adding fertiliser to the young cherry trees – we filled up our buckets with Cropzeal 16N fertiliser and walked up and down the rows throwing out a handful of it at the base of each tree. This particular fertiliser has a high nitrogen content with moderate levels of potassium and phosphorus, encouraging plant growth instead of flowering. It’s important to spread it out around the tree trunk so it’s not too concentrated otherwise reverse osmosis can occur in the root system.



April bud rubbing the cherry trees

The young cherry trees that were planted in winter needed to have some of their new buds rubbed off. Choosing which buds to keep sets up how the tree branches will end up growing. We rubbed off all buds under the guards, then left side alternating buds 200ml apart for the first meter of the tree and top buds for the last bit of the tree.


Me having a go on the tractor. Trevor looking concerned.

We started tractor skills this week but didn’t end up finishing the theory so don’t worry I won’t be zooming around the orchard just yet. Having two gear sticks is a bit odd.



Young apricot trees after fruit thinning

The young apricot trees were ready to have some of the fruit thinned. Removing some fruit means that the tree has more energy to put into the fruit that is left. They will grow much bigger! The tree needs about 7 leaves per apricot to mature and ripen as desired.


Buxus hedge after its hair cut (commonly called box hedging)

Karen and I tried to tidy up the hedge in front of the potting shed. The electric trimmers where already in use elsewhere so we only had hand trimmers. Buxus is a plant used in lots of traditional English gardens. Some people manage to make really cool topiary designs with it. It’s slow growing but drought tolerant. It needs to be trimmed regularly.


The long awaited plant sale finally happened on Saturday. It was a great day, really fun. I couldn’t believe how many people came. At one point I couldn’t see the end of the queue for the eftpos.

I was working on the tomato table. We had heaps of varieties available. I think the most popular were the Sweet 100s, Baxter’s Early Bush (both are cherry tomatoes) and Black Krim, it’s an heirloom tomato from Russia that is very dark in colour and apparently very yummy. I got one of them for myself so I’m looking forward to trying them. I’m keeping it inside at the moment since we are still getting frosts.

We sold out of the most popular tomatoes but there were some punnets leftover. Quite a few of the other plants all sold out. There were vegetables, flowers, natives and lots of drought tolerant plants good for the Central Otago climate.


A tiny selection of the veggies at the plant sale

Last week’s weather:

Term 4 – Week 1 – Irrigation


Cherry trees in blossom at Bannockburn Road

Term 4 has begun! A lot of changes happened over the last two weeks while it was school holidays. There is tons of blossom everywhere, on the vines buds have burst and leaves are starting to grow and the plants in the nursery have really shot up.


Tomato plants in the glasshouse


Baby cherries

Weather this week has regressed back to winter! It even snowed in Queenstown. There was a lot of rain overnight on Tuesday, about 32mm. One of the lecturers commented that it was the most rain in one go for about 4 or 5 years. Perfect timing since this week was all about irrigation!

Having a good irrigation system will help to get the maximum yield from a crop. Here in Central Otago there are two sides to irrigation. Irrigation of plants and frost fighting. Both need a huge amount of water, particularly frost fighting.

1mm of water over a hectare equals 10,000 litres of water. Here in Alexandra the annual rainfall is only about 400mm, some years as low as 280mm and growers will need to top that up with about 1000mm of water (not including water for frost fighting).

On Tuesday we went to McArthur Ridge vineyard to look at their irrigation system. It is a large property of 140 hectares so they have a huge irrigation system. They have two dams onsite where they get their water one for irrigation (15m deep!) and one for frost fighting. It was amazing to see the scale of the operation.


Half of one of the dams at McArthur Ridge – too big to get in one shot!



Pumps and filters for irrigation at McArthur Ridge vineyard


Two of the thirteen motors that run the frost fighting. $1.5 million worth of motors!

Orchards and vineyards will need to start irrigation from about now until the end of the growing season. To figure out when to irrigate you either need to run a water budget using evapotranspiration figures (Et) or have moisture sensors in the ground.

Evapotranspiration measures the combined loss of water from plants and soil. So the amount you would irrigate would be Et minus any rainfall. In summer Et can be 6 – 7 mm a day.


This week in propagation we did softwood cuttings of thyme and lavender. Softwood cuttings are taken in spring, using the new growth. Good plants to propagate using softwood cuttings are lavenders, hebes, lilacs and magnolias.

The cutting should be about the length of your little finger, taking the cutting just below a node. Keep the cuttings cool, mist and definitely keep out of the sun. The sooner you can get them done the better as they will wilt quickly. Remove any flower buds as they will keep trying to grow the flower instead of new roots. Dip the base into Seradix 1 hormone. Plant into a mix of half potting mix, half pumice. They should root in about 2 – 5 weeks.


Olivia, Mandeep and Pranel concentrating on the fiddly cuttings

Lavender is a great plant for Central Otago since it doesn’t need much water and can handle the sun. They have a faint fuzz that holds onto water, stopping evaporation. They are pretty low maintenance only needing to be pruned once a year after flowering. There are so many different varieties and even colours. I like the kind that looks like it has little petals on the top (they are technically leaves) but they don’t handle frosts very well.

lavande papillon lavandula stoechas 08d cpf 781

Lavandula stoechas (French lavender)

Last week’s weather:

Term 3 – Week 9 – Vegetables

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During the last week of Term 3 we took a look at vegetable gardens. We talked about the history of vegetable gardening, including the “Dig for Victory” campaign that was pushed during World War II when food was being rationed. I wonder how people would react now if the government had to initiate a rationing scheme.

Food security is one of the benefits of having your own vegetable garden; not needing to rely on New World for 100% of our food. In many areas if there was a natural disaster that cut off food supply lots of people would be vulnerable to hunger or malnutrition.

Other benefits of having your own vegetable garden include:

  • Fresh produce right outside your door
  • Cheaper than the supermarket
  • Less pesticide/herbicide used – or none!
  • Satisfaction of growing your own
  • Environmentally friendly – cutting down on resources

You can start a vegetable garden easily without a lot of equipment or flash potting mix, but I really like the look of this type of raised bed garden:


Left: Example of planting guide. Right: One of the vegetable gardens on Campus

Below are a couple of links to YouTube videos related to gardening that I found interesting. The first one is about setting up a community vegetable garden in Uganda.

The second kind of relates to food security. It’s about the last garden centre running in Aleppo (warning: it’s a tearjerker…)

YouTube video about a keyhole garden in Uganda

YouTube video about the last garden centre in Aleppo

On Thursday we did a lot of pricking out of the tomatoes. Tray after tray!


A small portion of the tomatoes ready for the plant sale

Last week’s weather: