Term 4 -Week 7 – Final Week of the Year

Butcher’s Dam – spring in Central Otago

This was the last week of the term. Final exams have been completed and for most students that’s it for level 4 horticulture. Since I started half way through the year I will be doing terms 1 and 2 next year.

In propagation this week we pricked out more of the lavendar cuttings that have rooted into individual pots and then moved on to seed scarification.

Seed scarification is where you physically damage the seed coat to initiate the germination process. This can be done by nicking the seed with a knife, rubbing with sand paper or other methods of cracking the seed coat.

Kowhai seed pods

Kowhai (or Sophora) is New Zealand’s native flower. They flower in August and native birds love them. 

The seeds are inside pods. To scarifiy them we popped them out, gave them a rub with some sandpaper. They are a bit difficult to get a grip on so I ended up filing my nails at the same time. Excellent multitasking!

Then they were sowed into hygiene trays, covered with vermiculite and put on the heat bed to germinate.

Potting mix trial

On the final day we checked our potting mix trial. Tui All Purpose was the winner (far left), with no plant deaths, no weeds and plants growing well. Yates Thrive was the loser (second from right), which was suprising as it was one of the more expensive mixes. It had a couple of deaths and look at the weeds! 

In the afternoon we had a final field trip to Peter Brass’ property. He’s retired but you wouldn’t know it from his operation. He’s got two hectares of cherries, a nursery growing all kinds of plants and a paddock full of garlic and potatoes.



All sorts – lettuce, herbs, veggies

He sells his produce and seedlings at farmer’s markets all over Central Otago. He also grows sunflowers to sell as cut flowers.

It was so interesting to see how he’s set this all up. He has such a huge knowledge of plants and growing. I thought it was interesting how he has diversified and gets to do a bit of everything; orchard, flowers, seedlings, food production.

The weather has been extremely changeable this week. Rainy and windy one day, sunny and scorching hot the next. More of the sunny days please!

Last week’s weather:

The last two terms have been great and I have learnt a lot, both practical and theory. I can’t wait to come back next year.


Term 4 – Week 6 – Birds & Bees


This week there was a different topic everyday. On Monday we completed our tractor skills theory. I passed the theory test so I’ll be allowed to take one for a spin shortly, woohoo!



Inside the hive

Bees play an important role in horticulture – pollination. Even plants that self-pollinate seem to do better when bees pollinate them as well. Many crops must be pollinated by bees or they won’t produce anything, especially kiwifruit.

The cherry orchard at Bannockburn Road, which is 1 hectare, had 12 hives during the flowering period. They cost $140 each for 3 weeks. Beekeeping can be a pretty good business if you want to get into it. One hive can produce 50kg of honey a year, or up to 100kg if it’s a really good year. The thyme honey made here in Central Otago is very popular in Asia.

Bee’s life cycle and division of labour is really fascinating. The queen is the only fertile female. Her only job is to lay all the eggs but will only mate once at the start of her reign, and won’t leave the hive again. Although that’s her only job, possibly her more important function is producing a pheromone that keeps the hive happy and in control. Without it the bees could swarm. If she’s an angry queen the rest of the bees will be aggressive as well. A beekeeper will replace a queen if that’s the case. A queen will usually be replaced every 1 – 2 years anyway to keep the pheromone levels up and reduce the chance of a swarm.

The drones are the only male bees. There are only a few of them and they don’t have any duties except waiting around for a new queen to mate with. In commercial beehives this never happens since beekeepers will replace the old queen with one who has already mated. In winter, or if food is scarce, the worker bees will force the drones out of the hive. Poor old drones.

The worker bees are all sterile females. They are the ones getting stuff done! They will live for 4 – 9 months over winter but only around 6 weeks over summer. The first few weeks will be spent in the hive caring for larvae and the queen, storing pollen, making wax etc. Then for the last few weeks they will be out collecting water, pollen and nectar. Some of them will also be guard bees, guarding the hive: fanning bees, keeping the hive cool: robbing bees, stealing any honey they can find.



Worker bee in action

Bird Management:

Birds can do a lot of damage to fruit crops. They will swoop in once fruit starts to ripen. This is particularly problematic for fruit that ripens on the tree like cherries and grapes. Apples and apricots are picked mature, but not ripe, so they have less to fear from birds.

Cherries will need protection from the 1st of December and grapes from February onwards. Birds are active from sun up to sun down but are more of a problem during their natural feeding times: 6.30am – 10am and again 4pm – 8.30pm.

The worst birds for fruit damage in New Zealand are:

  1. Starlings – a flocking bird that will bring all their friends
  2. Blackbirds – solitary but smart. They will even burrow under nets
  3. Finches – small therefore hard to shoot and will peck once in each piece of fruit (how annoying!)

In the past growers would use poison to get rid of birds but there is a move away from that style of management. Some places still shoot birds but that can be easier said than done on some properties, especially if there are neighbours! Also nets and other facilities can get in the way.

Bird damage is worse around the edges of a crop, so smaller plantings are at more risk. Nets are probably the best option and can limit damage to about 5%. They are really expensive though, about $60k per hectare.

Other management techniques include:

  • Shooting birds
  • Removing tall trees from the property so they have nowhere to roost
  • Gas guns to scare them away with the noise
  • Mirrors/lights
  • Bird Guard – a speaker system that emits bird distress calls (extremely loud and horrible, I couldn’t work in a place with that noise!)
  • Reflective ticker tape – birds don’t like the flickering light
  • Self launching kites shaped like hawks to scare other birds away

New technology is coming into this area. Drones could be used and there’s a product called Agrilaser that shoots a laser at birds that makes them fly away.

We used a much simpler technique to get the birds out of the cherry orchard – making as much noise as possible and chasing them out of the netted area.


Shedding cherries

While we were in the cherry orchard I noticed some of the cherries weren’t looking too healthy. You can see some in the above photo look quite shriveled. Apparently this is a normal part of the process, if more flowers have pollinated than the tree can sustain some cherries will shed now, leaving the remaining fruit to get all the energy the tree can provide.


Grafted apple tree – success!

I checked in on the grafted apple trees this week. They are going quite well. Lots of buds have pushed and there is new growth.


Young cherry trees – UFO system

They young cherry trees are looking good. The posts and wires will go in soon so they can be tied down. Once that happens the side shoots should start to grow up. The swarth could do with a mow…

This week the weather has really packed in. Windy and rainy every day. The hills around Cromwell and Alexandra are finally green! The thyme is flowering everywhere giving the landscape a purple flush of colour.

Last week’s weather:


Term 4 – Week 5 – The Lettuce Company


Row after row of lettuces

This week all the horticulture students did work experience somewhere. I went to The Lettuce Company, a hydroponic lettuce grower just outside of Clyde.

It was a really fun week and I learnt a lot from Mark and his team. The greenhouses are huge and hold thousands and thousands of lettuces at all different stages of growth. They grow four different types of lettuce: green oak (the most popular), red oak, green frill and red frill.

The first task I was given was sleeving up lettuces to be sent to supermarkets. It’s pretty simple. Pull the lettuce out of the growing tray, pull off any undesirable leaves around the base and wiggle it into the sleeve. They get put into boxes of 10, sprayed with water to keep them crisp and stored in the chiller before being sent out.


Lettuces in plastic sleeves


Ready for harvesting

All the water and nutrients the lettuce need flows through the growing trays and is recirculated. They use very little water compared to other growing operations.

I also found it interesting that they don’t heat the greenhouses in winter, they actually just heat the nutrients that flow through the roots. It does get down to about zero degrees in there and some lettuces will get a bit of frost damage.

When I was working there the temperature was around 32 degrees. Since it’s getting warmer now as summer approaches they are going to start working at 5am to miss the worst of the day’s heat. In winter lettuces take about 8 weeks to mature, but only 6 weeks in summer. The seeds we sowed on Tuesday will be harvested for Christmas.

One of the tasks I enjoyed most was putting out the seedlings that were ready to be separated into the grow trays. The seeds are sowed into grow dam – a felt like substance that sucks up moisture and stays wet.


You rip off each little block and place it into the grow tray hole.


Since it has been quite hot recently we had to spend a bit of time taking some seedlings  out of the hydroponic system that had grown too fast. They will be stored in the chiller to slow them down and put back out when needed.

Timing is really important make sure the lettuces can be moved through the glasshouse as necessary, from seed to seedling, to ready to be harvested. As big as the greenhouses are there is limited space in each section so you don’t want all the seedlings at the same stage and nothing else in any other section.

It was great to go home at the end of each day feeling like I had achieved something and even had some lovely lettuce to show for my efforts 🙂

Last week’s weather:


Term 4 – Week 4 – Dunedin & Grafting


Rhododendron Dell at the Dunedin Botanic Gardens

On Monday and Tuesday this week we went on a field trip to Dunedin. Our first stop was at Blueskin Nursery to learn about their production. They have a garden centre and cafe as well. A lot of their plants are orders from specific customers. They sell about 100,000 plants per year.


Blueskin Nursery


Seed raising glass house at Blueskin Nursery

It was a real surprise to see how basic the facilities are. Our equipment at Polytech is very flash in comparison!

After a quick lunch stop we raced off to Orokonui Ecosanctuary for a bush walk. There are heaps of amazing plants and native birds in the sanctuary. I saw Tuis, Tomtits, South Island kaka, Bellbirds and wood pigeon. There is a predator fence set up so there are no rats, stoats or possums that can harm the wildlife. There are even free range Tuatara in the sanctuary, but the only one I saw was one of the two they keep in a viewing pen.


Tuatara at Orokonui Ecosanctuary

Orokonui also claims to have the tallest tree in New Zealand, which is actually a Eucalyptus, not a native New Zealand tree.


Tallest Tree in New Zealand – I couldn’t fit it all into the photo!

On Tuesday we spent the day at the Dunedin Botanic Gardens which was fantastic. It was by far my favourite part of the trip. We had a behind the scenes tour of the propagation facilities. They did a full renovation a year ago and are now state of the art.

The gardens are massive and are so well done. My favourite areas were the Rhododendron Dell which was in full bloom and the Clive Lister garden which highlights different textures of plants.


A stunning rhododendron tree



Clockwise – Oriental Poppy, Rose, Carnivorous pitcher plant, Frangipani

On Wednesday we had a day on grafting. I had been looking forward to learning about how to graft and it was really interesting. November is the right time of year to graft dormant wood onto root stock (budding is done in February).

We started with rind grafting on to apple trees that had been stumped. This sort of grafting is called top working. Old trees can be given a new lease on life by removing the old grafted material and starting again with a new cultivar. Often you’ll need to leave a bit of the old graft (inter-stock section) or the stump will be too short.

On the stump you cut the bark and peal it back, then cut the end of the new wood on the diagonal. The new wood being introduced is called the scion. Insert the scion so the cambium layers join up (where the cells divide) so they can connect. Secure with tape. Leave two buds on and then cover the stump and cut wood with wax. We did four grafts per tree in the hopes that one will take. The others would be cut off later.


Apple tree rejuvenation

On Thursday we had propagation class where we did more cuttings. This time was herbaceous cuttings. They are from plants are soft stemmed and never get woody. These can be done at any time of the year.

The peonies on campus are looking gorgeous. The photo below shows the difference between early September and now.


Last week’s weather: