Autumn River

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If only I knew then...

Here are some of the questions that we wish we'd had answers to earlier. Some of them are things we've learned by trial and error, others are bits of information that we found after it was too late. Not all of them are things that have gone wrong, but all of them would have added to our ability to make a considered decision.

We are constantly adding information to this page, so if we have hinted at something but it isn't clear, or if there's just a short note to remind us to go back and fill in the detail, please remind us...

Dieback - what's wrong with my hazelnuts (late spring/summer)
Grass - what's causing the dead patches?
Orchard management - what are the understorey options?
Orchard management - should I spray out between my trees to give clear rows?
Grass - do I need to replace the pasture grass with slow-growing turf?
Irrigation - microspray or dripper?
Irrigation - when is the best time to irrigate?
Irrigation - how do I know when I need to irrigate? How much? How long for? How often?
Mowing - contractor, tractor, ride-on or farm-bike plus attachment?
Shelter requirements - what sort of shelter do I need?
Spacings between trees - what do I need to consider
Pruning
Nutrients
Cultivars
Will hazelnuts sucker throughout their lifetime or will they give up after a few years?

Dieback - what's wrong with my hazelnuts (late spring/summer)

After planting trees in July 2005, they seemed to be taking ok and putting out some nice new growth. A couple of months into spring, about 25% of them started to show some browning off of the leaves, and for most of these the branches started to die back.

A more common problem that we have is in early spring. The trees form buds over winter, but these just fail to develop in spring and the tree has to regenerate from a sucker. This means that you lose the previous year's growth completely and are starting over again each year for the first three or four years. It seems to be less of an issue after this.

We have conflicting information about this:

  • (Nov 2005, own theory) It only seems to affect the trees just planted, and then only the Whitehearts but not the pollinators. Could their root systems be too weak to support all the new growth?
  • (Nov 2005, consultant SB) Probably blight, could be controlled by a copper spray if caught early.
  • (Jan 2006, internet) Dieback can be caused by boron deficiency (which we think we have).
  • (Feb 2006, consultant SB) Almost certainly blight. The nursery has admitted that they had a bad outbreak and they probably never got it quite under control. Although they supplied the healthiest trees they had available, they were still in poor condition and the planting stress may have made them more susceptible to illness.
  • February 2008 (nurseryman and researcher MR) Probably not blight. Could be that the roots don't have enough resources to sustain the tree. The stem has enough energy for the first year when it goes in but when this is exhausted, if the roots can't supply enough then the tree fails. This seems to affect quite a few recent plantings, especially where the trees go in at a very small size (as ours have). It didn't used to be an issue because historically trees went in slightly older (after a couple more years growing on in the nursery).

Grass - what's causing the dead patches?

In summer we ended up with significant die-off of our grass, in large patches. Traffic areas (accessways) were least affected. At first we thought it was spray drift, but now we believe it is porina larvae, which burrow into the soil to develop and eat the grass off at ground level. It came back ok the next spring, but it was pretty distressing at the time.

No organic remedy we're aware of, the recommended action is an application of organophosphate in autumn. Opinion is divided as to whether you are likely to get annual reinfestations or whether it is random.

Orchard management regimes - what are the options for my understorey?

Understorey management is only an issue until the trees are big enough to achieve canopy closure and full shading of the ground (at this point, the tree roots will take all the water and not much will survive in the permanent full shade).

The most common understorey in establishing orchards in New Zealand is grass (see below), although other options are also available. These include:

  • a herbal ley. Our vague understanding is that this is a variety of grasses and weeds, which pull various nutrients out of the soil and allow you to mulch this back onto the plants. Natural fertiliser. It's a nice idea, but we haven't seen enough literature to evaluate this.
  • cash crop such as lucerne or barley. Also a nice idea, but it means you can't use the space between the rows for traffic or to manage your trees. This might work quite well if you don't want to use any control mechanisms around the trees (or can get to everything on foot).
  • bare earth. You could spray out all grass etc, although this could lead to topsoil loss and is also not a great way to retain moisture in the soil.

Orchard management regimes - should I spray clear rows between my trees?

The options available are to spray small patches around each tree, to spray rows, or not to spray at all.

If you are philosophically opposed to herbicides, the answer is probably no. It is not strictly necessary, but the trees will establish much better if they are not constantly competing with weeds and grasses so you should find a way to manage these (a dessicant spray could be used instead of Roundup etc).

Clear rows are easier to maintain than spray circles. Your spray tank can be mounted on a vehicle and you can go up and down each side of the row and do all your spraying quite quickly and easily. If you have grass between the rows, you can mow and mulch this onto the sprayed strips to retain soil moisture and return organic matter.

Spray circles can be maintained as a two person job, one to move the vehicle from tree to tree and the other on foot to take the hose and spray around (or one person could do it, hopping on and off). A 15 litre knapsack sprayer won't take you far! Mowing is also more difficult, you need to either do a criss-cross pattern or else figures of eight; neither of these is highly efficient.

Grass - which is better, pasture grass or slow-growing lawn turf?

This is a particularly tricky issue, as the answer depends on your priorities. (The size of your property is also relevant.) Fescue is probably not a feasible option for an organic orchard.

    Pasture grass Turf grass (fescue)

    Advantages

    • Cheaper to set up - it's usually there already.
    • Survives ok without too much irrigation (so less cost from pumping water etc).

     

    Advantages

    • Looks good - gives a smooth, even, bowling-green finish.
    • Lower maintenance - it grows slower, so needs cutting less often.
      • This is the point that is most often used to sell the idea as a practical advantage but please note that depending on your irrigation layout, it may not be any slower than pasture grass after all. If you are using a broadcast irrigation method, such as spray jets or microemitters, you will be irrigating the grass just as much as the trees. This makes it look lovely and green, but our experience is that you need to cut the grass at least every three weeks to keep it under control, which is the same sort of frequency as pasture grass.

    Disadvantages

    • Grows fast so requires frequent mowing or other control (after all, its main purpose is to generate enough green matter to sustain stock).
    • May grow unevenly so it doesn't always look particularly great.

    Disadvantages

    • Higher set-up cost because you generally need to cultivate the soil and sow new seed.
      • We strongly recommend that you spray out the old grass thoroughly first, probably a couple of months beforehand so you can do a second spray when it starts to regerminate and then still have time to plough it under to break down before you re-sow.
    • Higher set-up cost if you want to achieve the lush, green, bowling green finish because you will have to irrigate the grass as well as the trees. This means large pipes and more work laying it.
    • Maintenance costs because you may have to spray out aggressive weeds, which will almost always be more vigorous than fescue.
    • Harder to mow. Fescue has lots of very fine (and strong) blades of grass. To cut it successfully, you need to keep your mower blades really sharp. On good soil with good moisture, you will still need to mow it at least every three weeks (and preferably every two weeks) to keep it under control. Any longer than that and you will put unnecessary strain on your equipment.
      • We were told that this should only be the case for the second and possibly third years because this is when the grass puts on most of its growth for establishment, and it slows down after that (in the first year it is still sparse because it is establishing). We haven't seen any evidence of this so far.
    • For it to look nice with a bowling green finish, you need to have a very good weed control regime. Ideally, make sure none come up in the first place (hence the spraying out before sowing)

Irrigation - microspray or dripper?

Dripper is more water efficient, which can save money in many ways, including:

    • shallower bore
    • smaller pipework
    • less hassle getting a consent (maybe)
    • less time irrigating (maybe) = less electricity (only if the first holds)

To get enough water to the trees, you probably need to install a run of dripper tube down each side of the tree row. Leave enough slack that you could eventually move these outwards as the trees grow and their roots move out. Be aware that if you have dripper tube above ground, it will shrink in the sunshine so the rows will shorten (or if you have circuits, the joins will come under pressure and may pull apart).

Microsprayers are required if you have lawn turf and you want to keep it green in summer (otherwise it browns off completely, but should come back in winter). This pretty much defeats the real attraction of turf, which is the low maintenance - we are mowing ours every other week.

Microsprayers mean the trees' leaves are wetted, which could increase the risk of fungal diseases - but this has not been conclusively proven.

The stakes that the sprayers are on tend to get pushed out of the ground over winter as the soil contracts with frosts, so you may have to go around in early summer to make sure they are all correctly in place. Also, the tube connecting the spray head to the lateral may work loose so you will periodically need to check that as well.

What did we do? We have microsprayers covering essentially the entire block. Doing it again, we would probably use dripper tube.

Irrigation - when is the best time to irrigate?

Water soaks in better at night.

Daytime irrigation could burn the leaves.

Night time irrigation could increase the risk of fungal disease.

Irrigation - how do I know when I need to irrigate? How much? How long for? How often?

As well as the weather, this depends on your soil and how well it retains the water.

Mowing - contractor, tractor, ride-on or farm-bike plus attachment?

The economics of this question very much depend on the size of your property.

Contractors are convenient and a known cost, but very expensive on a large scale. On the other hand, you don't need to worry about maintenance, insurance, running costs and equipment storage. They are more skilled than a novice at handling the equipment and working efficiently, but then again they aren't emotionally involved so will almost certainly take less care than you. If you are strongly in favour of side discharge in order to mulch the rows, you will need to check whether the individual contractor's equipment supports this.

The commonly available ride-on mowers are designed for properties smaller than 10 acres. If you are larger than this, you will need to think about a grunty commercial model. Commercial models are designed to survive in a contracting or professional situation, so up to 8 hours a day, 40 hours a week. Petrol models start from around $20,000, and high-end diesel models are around $45,000 (including gst). Basically, you work out your budget then take the largest model that fits. We believe that the working life of a commercial ride-on in heavy use is around 10-15 years, if well maintained. The up-front cost probably works out about the same as using a contractor for 5 years. Running costs are on top of this, but on the other hand if the mower lasts longer then you are starting to win. Some of the leading suppliers have recently brought out large ride-ons in a 'heavy residential' grade (so slightly less rugged than the commercial mowers - presumably they were finding that people were scared off by the price tag). The life of these is more likely 5-10 years and there is more chance of a breakdown. If you want your equipment to definitely be working when you want to use it, there is more risk involved with these.

The cost of tractors depends on age, brand and size. It is quite common to purchase second hand tractors, but do try before you buy - some are much more comfortable and easy to handle than others. For size, think about what you will want to use it for in the long term and buy the size you will eventually need. The cost of a tractor plus mower unit is probably around the same as a large ride-on (and tractors cover the full range of prices too), but will last longer and should have lower running costs. As regards our Jinma, the tractor seems pretty sturdy but we're less certain about the mower unit. We have replaced three pulleys, gone through three sets of blades and replaced umpteen drive belts. Because it's a small brand there is no established support agent (the sales guy isn't geared to lifestylers), so it is hard to find parts. If you have a Jinma and have had problems, email us because we're happy to share what we've learnt!

Tractor mowers are driven by the PTO and most are pulled behind the tractor, which makes them difficult to manoeuver around planted blocks. Mid-mounted mowers are easy to manoeuver but hard to get at for maintenance.

Mower attachments for farm bikes can be fairly expensive, but are reputed to be longer lasting and more powerful than similar size ride-ons, simply because the mower unit has its own motor.

What did we do? We started out with a tractor and mid-mount mower. The tractor is great, the mower has been a constant source of frustration because it is always falling apart. After 3 seasons (so it has paid itself back compared with contractor), we are buying a top-of-the-line zero turn ride-on. 25 HP petrol motor, 60" side discharge.

The ride-on is about three times faster than the tractor, so each block will take about 15 minutes to cut instead of 45-60. The ride-on doesn't heat up as much as the tractor either - we had to stop for 30 minutes every 2 1/2 hours to let the tractor cool enough to not boil. This appears not to be an issue with the ride-on (maybe it is petrol vs diesel engine, or maybe just the design of the cooling system).

Another disadvantage of the tractor mower that we had was that it was hard to get on and off the tractor (actually, our from underneath). This meant that we had a dedicated mower but couldn't easily use the tractor for other equipment (eg sprayer, spreader, grader, post hold borer...), which is one of the big advantages of a tractor in general.

Shelter - what sort of shelter do I need?

The exact requirements for shelter depend on your site and its local environment, but basically you need enough shelter to protect the trees from harsh winds while they are establishing. If you don't have adequate shelter, it will slow your establishment significantly - by up to 5 years we think. If you are in Canterbury, where you can get several days of very strong winds at a time, you shouldn't even think of planting crop trees until your shelter is fully established.

On this count, we are the voice of sad experience. We were advised that walnuts would need shelter to be established for several years ahead of planting but hazelnuts should be ok planted concurrently, and we have found that our trees have suffered badly from this. The trees planted later, when the shelter is higher, have established much better than the trees planted earlier, with almost no protection.

Without adequate shelter, your trees may survive but are unlikely to thrive.

For more information on designing shelter and selecting shelter species, talk to your local nursery - in Canterbury, Southern Woods are very helpful.

What did we do? Our southern shelter (coldest winds) is leyland cypress. They took about 3 years to settle in but started to grow faster after that. When we were planning our layout we intended to plant hazelnuts on the western half and walnuts on the eastern half, and so we have two different types of shelter to accommodate this. For the walnuts, all the shelter is crowsnest poplars - tall, fast growing, deciduous so they don't provide too much shade (and frost traps) in winter. In the east, we have two schemes. For the nor'west wind (very strong) we have Italian alders alternating with poplars. For the nor'easter (not as strong, but much more frequent) we have Italian alders alternating with native NZ shrub species. The poplars are doing really well (also took a couple of years to get started but shot off after that) but the alders have been less successful (more fatalities for no known reason, but we suspect they need more water than we thought). Starting again, we would recommend allowing the shelter to grow for at least three years before putting in any crop trees.

Spacings between trees - what do I need to consider?

The space you need between trees depends on several different factors. The most important consideration is the size that the tree will grow. You need to have enough space between the trees that they can grow to full size comfortably and the edges of adjacent trees will just touch when they are mature (full canopy cover).

Most trees provide a better crop when they get plenty of sunlight on their branches and leaves, so make sure there is enough room for this.

The most efficient use of land area is to plant trees in an offset grid/diamond pattern. This means that you might plant a row of trees for example three metres apart. You could plant the next row three metres over, but instead of lining the trees up with each other in a square grid pattern, you could plant them so that the rows were staggered - the trees in the second row would be halfway between the trees in the first row; the trees in the first and third rows would line up. This gives the maximum canopy space per tree. Despite the mathematical elegance of this design, we haven't heard of anyone actually using it.

More commonly, trees are planted in rows. Within the rows the trees are fairly close together but the space between the rows is larger. This allows you to strip-spray herbicide around the trees to reduce competition from weeds and grasses while they are establishing, and also allows enough room for large equipment to work in your orchard. As well as mowing, don't forget that you may need room for a large tractor to spray fungicide or foliar fertiliser on your trees, or you may need room for a truck to spread granular fertiliser on the ground.

As well as space between the trees in the orchard, you also need to decide how much room you want to leave at the end of each row and at the sides of the block. This 'headland' and 'sideland' space give room to turn equipment at the end of the row. Five metres is the minimum you should consider and we would suggest that you actually leave more than this (and when we say five metres we mean actual space, not distance between the centre of the shelter tree and the centre of the crop tree). This gives you much more flexibility when considering maintenance options. On the other hand, that is valuable space that you are not cropping - how much would you earn by having trees in that space and how much do the different maintenance options cost you?

What did we do? Whiteheart hazelnuts are fairly small so ours are planted in rows, 2.2 m apart in the row and 4.5 m between the rows. Our headlands and sidelands are 5 m. In practice, this works well for routine management - we have sprayed the rows out to 0.75 m each side of the trees so we have a mowing strip of 3 m which we cover in two passes. However, it is hard to find a contractor to spread bulk granular fertiliser because the headlands are too small for them to turn a large spreading truck. While the trees are small, 2.2 m looks like plenty of space between them. However, when they get a bit bigger this may be a little too close. Starting again, we would probably allow 2.5 m between the trees so that we could train them into a more conventional open vase shape. As it is, we will probably have to use something more like a flattened cone. We would also allow more space at the headlands, more like 5.5 m of clear space (between the end of the sprayed hazel strip and the edge of the shelter sprayed strip).