Term 3 – Week 5 – Mix


Potting mix experiment – will anything germinate? 

This week was something different everyday. On Monday the topic was Soil-less Media, which is basically a fancy way of saying potting mix. Ingredients can include peat, bark, compost, sand, coir fibre (coconut husk), fertilisers and wetting agents.

We looked at several different varieties of commercial potting mix and the Polytechnic’s own potting mix blends to see the differences. As as experiment to see how they perform we have filled a tray with each variety and will leave them in the greenhouse on the mist bed. I’m interested to see if any weeds germinate – in theory there should not be any.


Examining the contents wearing masks to reduce the risk of Legionnaires Disease

On Tuesday we took a trip to Naseby to go curling.  The outdoor rink wasn’t frozen anymore but luckily there is an indoor facility there. It took a few turns to get used to sliding the heavy stones over the ice. I really had to build up the momentum before releasing the stone otherwise it didn’t make it to the other end, over the ‘hog line’ as they say in curling. It was great fun and I would definitely do it again.


On Wednesday we were back at it planting the cherry trees. We managed to get all the trees in just before it started raining, which I was very pleased about. I was muddy enough already!

On Thursday Annabel Langbein and a chef from the USA came to the campus for a cooking demonstration and talk on eating locally grown or sourced food. I enjoyed the cooking demo (and sampling the results!) but the message on eating local and in season didn’t really come across or fit with the ingredients they used. Chili’s from Fiji and green papaya for example.


Scampi! Yum!


I checked up on the geraniums in the glasshouse. They are progressing well and starting to get their next leafs.


Baby geraniums

This week’s weather has been fairly warm with some rain on Wednesday afternoon that got heavier in the evening and dried out overnight. Only a couple of frosty mornings.




Term 3 – Week 4 – Grow Safe


Viola – ‘Sorbet Fire’

Spring is definitely in the air here in Central Otago. Things are staring to pop up all over the place. My violas are brightening up the garden. There have been a few frosty mornings this week but nowhere near as cold as it has been. The afternoons have been quite warm especially if you’re out in the sunshine.

On Monday and Tuesday I completed the Grow Safe certificate for horticulture and viticulture. It’s a course about the use of agrichemicals; being able to use them safely and effectively. It covered a lot of material, from basics like safety gear to how to manage the risks. Reading through the list of hazard classifications associated with some sprays makes it clear how seriously you need to take it.

For example:

6.7A – carcinogenic to humans
8.3A – corrosive to eye tissue
9.1A – very ecotoxic in the aquatic environment

Apparently 75% of agrichemicals are toxic in water so there’s a strong emphasis on not contaminating ground water or waterways. Pretty scary stuff.  Wayne (lecturer) mentioned how the safety recommendations are constantly being updated. One agrichemical he’s used for years and years is now considered much more toxic than previously thought and will probably end up off the market. I wouldn’t want a job as a sprayer where you are potentially exposed day in and day out.

Having said that, there are ways to minimise the potential harm with good spraying practices, like always trying to limit spray drift. That means only spraying when conditions are suitable. If wind is over 10km/h (a moderate breeze) drift will start occurring, especially if the spray is fine. And what’s the point of that? You would be wasting the chemical if it’s just blowing away.

You would also be wasting your spray if it’s too hot (the water evaporates in the air and the chemical never makes it onto the plant) or if it’s too cold (spray doesn’t dry and wrecks the fruit or leaves).

There was a practical test as well that included getting into the gear, measuring and mixing up a spray (it was just water for the test), spraying and emptying the tank correctly.


Richard completing the practical test

On Wednesday we were back at Bannockburn Road campus to plant more of the new cherry trees. We ending up getting about 450 planted. Only 450 more to go!


Trees transported by Trevor on a tractor

The plastic guards have been put on now. They protect the young trunks from rabbits and sprays. There is also going to be a rabbit fence set up to keep them out.


Newly planted cherry trees at Bannockburn Road

Thursday was propagation in the nursery. Jo (lecturer) talked about tissue cultures that get sent to a lab for propagation, which was really interesting. Hopefully we’ll get to see some that have come from a lab at some point over the year.

Then we were onto practical work in the nursery. Sowing coriander seeds (which smell amazing!) and some odd jobs like weeding.

I added fertilizer to the chionochloa rigida (snow tussock) that are going to be planted at Lindis Pass. About 1/2 teaspoon per pot.


Adding fertilizer to the chionochloa rigida

They are sub-alpine plants and are really important to the area. They prefer drier areas and grow above the tree line.

Michael and I drove through Lindis Pass at the start of autumn and it’s a stunning landscape.


Lindis Pass

More proof that spring is on the way; Jo brought examples of snowdrops and snowflakes. Snowdrops only have one flower, snowflakes have several. Personally, I prefer the look of the snowdrops. I’m going to try to remember to plant some bulbs next year – so pretty!


Snowdrop vs snowflake




Term 3 – Week 3 – Enterprise Report

This week we made a start on our Enterprise Reports. An Enterprise Report is an analysis of a horticultural enterprise including details on the property and activities. It is broken down into 3 sections:

1 – Physical features including location, size, climate, topography etc

2 – Production features including plants or crops grown, growing methods, crop production schedules etc

3 – Management features including personnel, management methods, new technology, client base and future trends

I have decided to do my report on the Campus Nursery Complex. I started by photographing all the buildings and facilities that make up the nursery and I’m now working through typing up each section of the report.


A few of the buildings that make up the nursery at the Central Campus

Wednesday this week was spent at the Bannockburn Road site to plant the new section of cherry trees. There are 500 Romance cherry trees and 430 Sweethearts to be planted.

First we worked in groups to come up with a planting plan for the trees. Trevor already had the real plan worked out so this was more for the experience.

The plan was to plant them using the Upright Fruiting Offshoots (UFO) system. The rows are 2.5 meters apart with the trees 2 meters apart. In the UFO system the trees are planted at a 45 degree angle and are trained to grow along wires. This has a lot of benefits, easy pruning and picking, uniform light distribution and using the cherry trees natural ability to grow upright shoots.


Cherry trees planted using the UFO system

However, not all the 930 trees would fit into the site using just UFO. The remaining trees would need to be planted using the Super Slender Axe (SSA) system. SSA is more high density than UFO so it made sense to have a couple of SSA rows to fit in more trees. Trees are planted only 1 meter apart, so double the number per row than the UFO system.


Difference between SSA and UFO training systems

Once the plan was in place we went out to the empty site and started by measuring off the corners and getting the rows marked out with string. Then working down the rows and marking every 2.5 meters with spray paint.


Measuring and marking for planting


Next, the hard part started – digging!


Digging holes for the new trees to be planted

Then the fun part – planting!

We’ll be back at it next Wednesday to get more planted. Only 800 to go!

Thursday was another propagation day in the nursery. The bare rooted trees had arrived from Appleton’s Nursery and they needed to be put into pots. It was so interesting to see how they bag them up to be sent to customers.


Bare rooted trees arrive at the nursery. 300 trees in those 2 bags!


There were also some seeds to be sowed to get ready for the Spring Sale in October. I did a tray of chives. These were put straight into 4 x pot punnets unlike the geraniums I did last week that went into one big hygiene tray. This means they won’t have to be re-potted.


Since I was in the nursery I checked up on the geraniums we planted last week. I’m happy to say they are looking great! Heaps of little sprouts sticking up. They have done so well they were ready to move from the heat bed to the glasshouse.


Geraniums have sprouted! Grow babies grow!

The weather this week has cold but clear. Frosty mornings and sunny afternoons.




Term 3 – Week 2 – Composting


Checking out the compost at Felton Rd vineyard

Monday to Wednesday this week was dedicated to learning about composting. Who knew there was so much involved in making good compost! The basic elements are carbon to nitrogen ratio, water and oxygen. The balance needs to be right to get the compost decomposing. You can tell it has started working when the compost pile heats up. The bacteria, microbes and insects have got to work! It can get as hot as 70° Celsius, usually it will get to around 50º C and then start to cool down. This is when you can turn the compost, supplying more oxygen to get it going again. The high temperatures help kill off weed seeds and any diseases from plants that have been included in the batch.



Compost can be made out of just about any organic material. It will all breakdown eventually. Then end result is called humus (pronounced ‘Hugh-miss’ not hummus the chickpea dip). Humus is dark brown, nearly black, and has a light earthy smell. The right balance of carbon to nitrogen will mean the compost is completed a lot faster. High carbon items are called ‘browns’ and high nitrogen ‘greens’. Ideally you would mix them so the ratio of carbon to nitrogen is 30:1. When it is finished composting the remaining humus has a ratio of 10:1. This is now very stable and will not breakdown further.


To test if the compost is ready to use you can seal a small amount in a plastic bag overnight. It shouldn’t puff up the bag or give off any odors. To test the quality of the humus you can use it as potting mix for something like radishes. If they sprout successfully, great! If not, something is a bit off. Maybe there are too many salts leading to reverse osmosis or pesticide contamination.

We went out to Felton Road Winery in Bannockburn to see how they create and use compost on their vineyard. They have a bio-dynamic philosophy to making wines based on the ideas of Rudolph Steiner from the 1920s. It’s not based on hard science (no real research done) but works for them and as Gareth said, at least it’s not doing any harm. They do make delicious wine, so maybe there is something to it.


Compost pile at Felton Road vineyard – insulated with hay

They make their compost out of the pruned vine canes and other crops they have harvested onsite. They believe using plants grown onsite means the compost won’t change the terroir (environmental factors of a specific piece of land) that is expressed in the wine. They make several compost piles around the property. This means it is easier to access and spread where needed.

Thursday was my first day in the nursery for propagation. We started with an induction, health and safety and a tour of the facilities.


Glasshouse at Central Campus

A nice warm place to spend a cold winter’s day.


Above: Hanging baskets for the Alexandra Blossom festival. Below: Greenhouse plants.

I planted some geranium seeds in a hygiene tray using a 50/50 mix of potting mix and sand. You fill the tray with the seed raising mix, then level with a float. Sprinkle the seeds on top. Hopefully spread out evenly. The geranium seeds were a bright gold colour that made it really easy to see where they were even though they are so small. Then cover them with vermiculite and store in the greenhouse. There they will be watered by the mist sprinklers and then covered with a glass screen to help heat them up and not get too wet to start with.


Geranium ‘Maverick Scarlet’ seeds planted

I can’t wait to check next week to see what has sprouted! When they are bigger they will be individually potted and eventually sold at the school’s annual plant sale in October.

Weather – Snow was forecast all week but never arrived. Mornings were frosty. It rained heavily on Wednesday night through to Thursday morning.