Many of us may dream of owning a citrus orchard, but sadly few of us have space to make our dream a reality.
Our grandparents may have aspired to the quarter acre block, but these days the average home garden is 0.1 hectare. This means a couple of lemon trees or a kumquat bush in a pot by the front door for many of us, rather than a full citrus orchard.
And let’s not forget the growing conditions. You need plenty of sun and free air flow for a citrus orchard to flourish, although you may be able to get round this issue if you are happy to move potted citrus bushes from place to place as the seasons change. Obviously, this takes dedication and there’s nothing more frustrating than nurturing a plant for years to have it wiped out by a single exposure to frost when you forget to move it within the range of a protecting wall. Or, if you go away for a week or 2 and your house-minder fails to read the weather report and accidentally neglects your beloved mandarin’s welfare.
If you aren’t either willing or able to commit to a long-term citrus care plan, or you may as well plant something else.
Protect Against Frost
Citrus hate frost.
There are a few exceptions to this – the ‘Lisbon’ lemon has been known to survive -2C of frost and the tangelo is pretty hardy in cold weather – but this is not the norm. Unless you undertake some extensive protective measures, like covering your plants in some form of plant protection frost cover or citrus tent, a heavy frost will kill your citrus orchard before it gets started.
Other precautions to consider against the ravages of frost are spraying your trees with water before dawn, to prevent the warm of the sun from rupturing the frozen plant cells as they thaw. This is effective because water from the mains supply will be relatively warmer than the frost-stiffened leaves of your citrus plants and so it will defrost them more slowly and gently than the sun, so limiting the damage caused. The same theory is at work in areas prone to chilly nights, but home to acres of citrus orchard like Sunraysia. If you visit regions like this before dawn, you’ll find the irrigation water canons blasting at full-pelt.
And if you don’t fancy getting up before sunshine on a frosty morn with a watering hose in your hand, planting your citrus orchard in pots that you can move around to take advantage of shelter and warm patches is probably the best solution.
The rule of thumb when transplanting citrus is that they like a hole three times that size of the container that you are taking them from. This means that if you buy a grapefruit plant in a 255mm (10 inch) pot with a four litre capacity, the smallest hole that you should consider digging for it is twelve litres in measurement. This will allow the roots to run for a year.
Prepare the hole with compost or shredded copra. Copra is useful as the compressed bricks are easy to come by and are a renewable by-product of the coconut industry, unlike peat moss. Both compost and copra help young plants absorb nutrients.
See here, for more on the ideal soil for citrus.
If you are planting your citrus orchard in heavy, clay soils don’t forget to mix in some gypsum to open up the soil structure. And remember to use a fork rather than a spade in wet soils. When you slice wet soil with a spade, it creates a polished cut that roots may find it hard to penetrate. Moisture may also find such cuts difficult to cross. In contrast, the rough cuts left by a fork aid the root run.
And if you’d like to know a little more about this, see this factsheet.
Raised or Flat?
This depends on the dampness of the soil.
If you are planting in wet soil, it pays to build a mound of soil about 10cm high and level it off so that at least 10cm of the newly planted citrus’ root run is safely above the saturated water level of the soil.
If you have well-drained soil, this is not necessary.
Plant your citrus with the bud union clear of the surface of the soil and make sure that there is no organic matter up against its trunk, or you may find that it starts to rot. Citrus are not fans of compost or leaf litter against their bark. Lemons are particularly sensitive to this and will succumb to collar rot surprisingly quickly if you leave organic matter touching their bark for too long. To ensure that your fledgling citrus orchard doesn’t dwindle before it takes off, remove all organic matter from around the trees trunk and then daub it with a slurry of Bordeaux mix (or something similar), which is a contact fungicide.
When to Plant your Citrus Orchard?
As ever, different growers in various parts of Australia have differing views on this.
In the southern states, citrus tend to be sold at the same time as open-rooted fruits and nuts, in the winter months. Personally, I like to leave them until spring when the soils are a tad warmer.
In sub tropical regions, citrus trees will generally thrive as long as the soil is suitable, the rootstock is healthy and there’s plenty of water. Water is a vital factor in extending their planting season.
To Tease, or Not To Tease?
So you’ve dug and prepared your hole and are about to plant your tree.
But before you pop your orange bush in the ground, do you tease the roots out or leave them be?
In general, citrus appreciate a gentle teasing. As you put them in the plot, backfill the plant, drawing it up as you place it in. This allows the crumblier soil to be worked back in around the roots. Once this is done, tamp with your hand and water it. This will remove any air cavities that may have formed and prevent any tiny feeder roots from drying out – and adversely effecting the health of the tree.
Finally, no young plant likes to be fighting for nutrients with weeds and citrus are no exception.
The choice open to you are the age-old toil of careful monitoring and regular manual gardening, or to adapt a more modern approach and hit your citrus orchard with a glyphosate spray (or another herbicide) every couple of months – ideally in the still of the day. Glyphosate doesn’t leave a residue in the soil and actually breaks down the structure of the chlorophyll in the weeds, which means that they collapse from exhaustion.
Top tip – when applying the glyphosate, make sure that you don’t get any on your citrus trees or the herbicide will get to work on them – usually as leaf burn. It would be a real shame to go through the hard work of planting out your citrus orchard only to kill it with a careless application of herbicide!