'In the twenty years I have been doing talkback radio, there has never been a program where citrus questions didn't pop up. So frequently in fact that producers screen the calls and cap them at three per program,' says Hahn.
This pocket-sized gardening book is packed with juicy tips on how to grow happy healthy citrus plants in your garden. Bringing together lemons, limes, grapefruits, kumquats, oranges and much more, you'll love this quick, practical and environmentally-friendly guide to common problems.
'Smail In slze, its packed with practically all you need to solve citrus problems and grow the juiciest fruit.' Better Homes & Gardens
'In the twenty years I have been doing talkback radio, there has never been a program where citrus questions didn't pop up. So frequently in fact that producers screen the calls and cap them at three per program,' says Hahn.
This pocket-sized gardening book is packed with juicy tips on how to grow happy healthy citrus plants in your garden. Bringing together lemons, limes, grapefruits, kumquats, oranges and much more, you'll love this quick, practical and environmentally-friendly guide to common problems.
'Smail In slze, its packed with practically all you need to solve citrus problems and grow the juiciest fruit.' Better Homes & Gardens
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Overview
'In the twenty years I have been doing talkback radio, there has never been a program where citrus questions didn't pop up. So frequently in fact that producers screen the calls and cap them at three per program,' says Hahn.
This pocket-sized gardening book is packed with juicy tips on how to grow happy healthy citrus plants in your garden. Bringing together lemons, limes, grapefruits, kumquats, oranges and much more, you'll love this quick, practical and environmentally-friendly guide to common problems.
'Smail In slze, its packed with practically all you need to solve citrus problems and grow the juiciest fruit.' Better Homes & Gardens
Product Details
| ISBN-13: | 9781922089168 |
|---|---|
| Publisher: | Fremantle Press |
| Publication date: | 10/01/2012 |
| Sold by: | INDEPENDENT PUB GROUP - EPUB - EBKS |
| Format: | eBook |
| Pages: | 144 |
| File size: | 2 MB |
About the Author
Sabrina's radio career began in Kalgoorlie in 1985 and she has worked in ABC gardening radio ever since. Sabrina took up boxing at the age of 40 and, many bruises later, earned her black belt. Sabrina's work in remote Aboriginal communities in WA's Kimberley region has been a huge success and helps ensure that the knowledge of bush tucker plants is passed on from one generation to the next.
Read an Excerpt
Sabrina's Juicy Little Book of Citrus
By Sabrina Hahn, Naama Amram, Tracey Gibbs
Fremantle Press
Copyright © 2012 Sabrina HahnAll rights reserved.
ISBN: 978-1-922089-16-8
CHAPTER 1
Propagation and care
Propagation
Citrus can be propagated by seed, cuttings, aerial layering, or budding and grafting onto selected rootstocks. Most of our citrus today is grown by grafting budstock onto a rootstock seedling. Few people grow citrus from seed because of its high genetic variability, but basically that's how citrus conquered the world. You couldn't get a better container to carry seeds on long journeys than the fruit they're in.
Growing from seed
The most important factor is to use a fresh seed. Once you have picked the fruit from a tree, wash the seeds and plant them in a seed raising mix in a warm spot out of the sun. Choose fat seeds; you can float them in water – the seeds that float will not have an embryo and should be discarded. Each seed should be planted at a depth equal to twice its height.
Use a fine mist to water the seed trays. Germination will occur within 3 weeks. Young seedlings may be pricked out 2 weeks after germination. Interestingly, a citrus seed can produce more than one plant per seed – sometimes up to four – and they will be identical to the parent plant. These are called nucellar embryos. Some seeds may be the result of cross-pollination and will have the diversity of the two parents. Citron and pomelo are monoembryonic, meaning each individual seed has only one embryo.
If it's all too much to think about the polyembryonic and monoembryonic state of a seed, these are fabulous words to use in a sentence at boring parties. You will find most people will either leave you alone or stop talking.
There are risks to growing your citrus from seed and one of them has to do with age: it can take anything from six to thirty years before you see any fruit. If you are young enough that this doesn't bother you, give it a go – you could discover a new variety. The downside is that many seedling trees are full of thorns and susceptible to diseases.
Growing from cuttings
Citrus can be grown from leaf bud, semi-hardwood and softwood cuttings. Depending on the type of citrus, you can wait from 4 months to a year before the cutting has good root development.
Let's go for the easiest one first for the keen novice gardener.
Leaf bud cuttings
These are easy to play with. It's best to have everything ready and prepared before you take the cuttings so they don't dry out. You will need:
• Seed trays
• Hormone gel for softwood cuttings
• Seed raising mix
• Clean sterilised secateurs (wipe the blades with methylated spirits)
• A spray bottle filled with water
Take several cuttings along a branch. Each cutting should have a bud (it's where the leaf junction comes from, but remove the leaf) and a piece of stem that is about 6 – 10mm long. The stem will need to have a piece above the bud and a piece below the bud. It will look like this (before you've removed the leaf):
Dip the bottom bit of the stem into the hormone gel (you will know what the bottom bit is because the bud should be facing up) and put upright into the seed raising mix.
Using a spray bottle wet the whole area and cover the seed tray with a lid to prevent loss of moisture. Keep in a warm place out of the sun; allow air in during the day and close it up again at night.
The cuttings should form roots and shoot away in 4 weeks. They will then need to be transplanted into individual pots in a good quality potting mix until they are large enough to pot up again into a larger container.
Semi-hardwood cuttings
You will need:
• A large pot or several pots
• Propagation mix
• Hormone gel for semi-hardwood cuttings
• Wire
• Bubble wrap and tape
• Secateurs
• A spray bottle filled with water
These are the largest cuttings from stems and will need to be 10–30cm long. These cuttings must be kept warm and moist at all times. You can plant up to 4 cuttings in a large pot.
Again have the pots, wire and bubble wrap all ready before you take the cuttings. Fill the pots up with the propagation mix and water it till it's damp but not soaking. After taking the cuttings, remove the lower two thirds of leaves. You will only have a few leaves left at the top of each cutting.
With a pencil, prepare holes in the propagation mix for the cuttings to slip into.
Scrape a small amount of the bark diagonally off the bottom two centimetres of each cutting and dip this end into the hormone gel.
Slip the cuttings into the holes and push the propagation mix around them to make them stable. Make sure the mix is damp and then mist spray the cuttings.
Create a wire frame by pushing two arched wires into the pot and cover it entirely in bubble wrap, top and sides. Make sure the plastic does not touch the cuttings.
Keep the pot covered until you think it may be drying out. Only use the mist spray to water the cuttings and always cover up the pot again until you see roots developing at its bottom. It may take up to 4 weeks. The cuttings then can be pricked out and potted up into slightly larger pots.
Softwood cuttings
You will need:
• A polystyrene foam box
• Propagation mix
• Hormone gel for softwood cuttings
• Plastic wrap
• Secateurs
• A spray bottle filled with water
These are cuttings taken from new growth and will only be 5–8cm long. They will be floppy at the top and will need high humidity and moisture to form roots. One of the best things the home gardening enthusiast can use to propagate softwood cuttings is those foam polystyrene boxes that your cold seafood or veggies come in. They are leak-proof, insulated and you can put a plastic wrap cover over them to allow light in while keeping them sealed. You will need to place the box out of direct sunlight but in a warm spot.
Have everything ready before you take the cuttings. Fill the foam box with propagation mix, water it and use a pencil to make little holes for the cuttings.
Take the cuttings from the new soft growth and dip the bottom into the hormone gel. Plant them into the foam box and spray them with water.
Wrap the top of the box completely with plastic wrap and leave all snug and tight for 2 weeks without lifting the wrap. Mist spray once again and rewrap. They should form roots within 2 – 3 weeks and then can be pricked out and potted up into slightly larger pots.
Budding and grafting
All the trees you purchase from the nursery with the exception of Lots-a-Lemons (it's grown by cuttings) will be a selected variety (the scion) that has been grafted onto a rootstock. The benefit of this is that you will have an identical tree to the one the scion is derived from. This is great because you know what you are getting.
More gardeners should try their hand at grafting – it's a great way to grow your own fruit and bud grafting is the easiest. You can also rework old varieties that you don't want anymore or that have more than one variety on a tree. Grafting for citrus usually takes place in spring or early autumn and budding is done in spring, summer or late summer when the sap is more active.
A bit of terminology that will help you understand what grafting is all about:
Scions(not a planet that Captain Kirk visits) are small pieces of stem that have 1 – 6 buds, taken from a donor tree. A scion will be identical to the parent plant and once established becomes the major part of the stem system on the new plant. This is your new tree.
Cambium layer is a layer of cells found just under the bark of a plant. These cells produce the growing tissues of a stem, root or leaf. The cambium layer is vital for the distribution of water and nutrients.
Rootstock is a plant on which other varieties or cultivars of plants are grafted and which provides the root basis for the grafted tree. Rootstocks are chosen for particular soil types, climates and pest and disease resistance (see section on rootstocks).
The easiest types of budding and grafting for the home gardener to try are:
• T-budding
• Chip budding
• Whip-and-tongue graft
You will need a bit of equipment to get the best results. The best tools are a budding knife and a very good pair of secateurs. These must be kept clean and razor sharp for grafting. Budding knives will have only one side of the blade sharp to avoid any ripping of bark. Some gardeners use a pocketknife, which is also acceptable, but the job is easier with a budding knife.
The next item on the shopping list is grafting tape (also called budding tape) – used to totally seal the graft, prevent moisture loss and protect the bud. The tape is left on until the bud shoots away. My mother was a great gardener and often reworked her fruit trees by grafting. For the larger grafts she used to use a rubber glove that was sealed at the top and bottom with butchers string. Necessity is the mother of invention. That was in the days when you had to come up with your own solutions to problems using only what was available. Bloody good use for a rubber glove – better than doing the dishes.
Grafting is all about keeping the cambium layer of the scion in complete contact with the cambium layer of the rootstock, as close together as possible with no air gaps between. And yea verily, the two shall match perfectly and the fruits of your labour shall burst forth (in a year or so – not so much a burst, more of an amble).
T-budding
This is the most common type of grafting for citrus. It is popular because it is easy and you can do multiple bud grafts on the one tree. The best time to bud graft is from early summer through to autumn. Basically you are going to insert a small piece of bark that has a bud into the bark of the rootstock plant. The budwood is very small so a bit of careful handling is needed. Slice the budwood off using either a scalpel or a sharp budding knife (1 and 2).
On the stem of the rootstock (from wood at least two years old), make a T-shaped cut (one horizontal line and the other vertical). The vertical line should be the same length as the budwood (3). Carefully lift the bark back from the rootstock stem and insert the budwood under the bark, making sure the bud sits in the middle of the T cut (4).
This may sound really stupid, but the bud must be the right way up; it should be facing upward. If it is upside down, you have mucked up the whole process and nothing will happen.
Now comes the part where the waves crash on the shore, romantic music is playing and the cambium layers meet. Grafting is all about matching cambium layers and getting them to squeeze together. You might say their romance is budding. Once the bud is inserted into the graft, wrap it tightly with grafting tape (including the bud) to keep the cambium layers in contact (5). Leave the tape on for 3 – 5 weeks and the bud should have a little spurt of growth. Then remove the tape and prune back the rootstock branch to just above the bud (6).
Chip-budding
Chip-budding can be done nearly all year round. It requires a small piece of bark with a bud from the scion inserted into a small recess on the rootstock. You are going to create an angled chip from the budwood.
Using a grafting knife, cut the budwood from a healthy lateral. Cut at a 30-degree angle running from 1cm above the bud to 1cm below. Then make a second cut at a 45-degree angle downwards until this meets with the first cut (1). This will create a wedge-shaped chip (2).
Make similar angled cuts of the same size into the branch or stem of your rootstock (3) and slip the bud chip in (4).
Bind with grafting tape, completely covering the bud chip (5). Leave the grafting tape on for 3–5 weeks (depending on the time of the year – less in spring and summer). You will see the graft has taken when there is callusing around the cut on the rootstock.
Once the graft has taken remove the tape and cut the rootstock branch back to the inserted bud (6). This is important because the bud will not grow if the rootstock stem is left on.
Some gardeners use bubble wrap or a plastic sleeve over the top of the graft to increase the warmth and hasten the time it takes for the graft to seal. Never do this in midsummer in hot temperatures because you will cook the bud. It is, however, a more efficient way of grafting in the cooler months.
Whip-and-tongue graft
This is another popular method of grafting for the home gardener, but you will need scion and rootstock with the same diameter. You will be using a stem cutting of the scion that is at least three buds long, and grafting it into a rootstock that has the same diameter so that the cuts you make in one fit into the other.
Make a long sloping cut on both the rootstock stem and the scion stem at a 30-degree angle (1). You will be cutting each stem in the same direction, so that when the scion is sitting upside down on top of the rootstock it becomes a perfect opposite.
Then make a second cut in each stem, running about 2 – 3cm deep into the slope in a similar angle to the first cut (2). This will be the tongue (3).
When the stems are joined, the tongue of the scion should fit into the split in the rootstock (4). It sounds complex and you may need to have a few cracks at creating the whip and tongue, but it's a great technique to master.
Wrap the whole grafted area with grafting tape and cut the leaves of the scion in half (5). This reduces transpiration. You can place a plastic sleeve over the entire graft, including the scion leaves, if the weather is cooler.
Rootstocks for citrus trees
Nearly all the citrus trees you buy in nurseries will be on a grafted rootstock. That's because different rootstocks perform better in different soil types and climates and are less susceptible to diseases such as phytophthora, tristeza and exocortis. Some rootstocks have a dwarfing effect and others are nematode-resistant (see pests in section entitled "The piercers"). Many rootstocks are a cross between two different species of citrus. Your local nursery will supply grafted trees on a rootstock that is most suitable for your area. Only a few varieties of citrus are grown from seed or cuttings.
Benton Citrange (Poncirus trifoliata x Citrus sinensis)
The favoured rootstock for Eureka lemon and for areas that experience frosts, but weakens at the knees at any hint of salt. It is resistant to phytophthora and collar rot.
Cleopatra Mandarin (Citrus reticulata)
Used extensively for mandarin cultivars, it is resistant to root rot and performs better in heavy soils with loam or clay.
Flying Dragon (Poncirus trifoliata var. monstrosa)
Used as a rootstock on many of the dwarf varieties of lemons and limes because of its growth limitations, tolerance of cold winters and disease resistance. It is very thorny, resistant to tristeza virus and thankfully also to nematode attack. Not to be used for Imperial Mandarin grafts.
Rangpur Lime (Citrus limonia)
Produces good quality fruit and heavy crops. Used in soils that have a high pH and some degree of salt. It is tristeza virus – resistant.
Rough Lemon (Citrus jambhiri)
Can be grown from seed and was used as a rootstock by commercial growers because of its drought tolerance. A bit of a Yin and Yang factor though as it was discovered to be susceptible to nematodes, phytophthora and collar rot. It is only suitable for free-draining soils. The fruit is less juicy and has less sugar. Not suitable as a rootstock for mandarins.
Sweet Orange (Citrus sinensis)
Not as resistant to phytophthora or nematodes, but a good rootstock for free-draining soils. It produces a very large tree with heavy crops of juicy fruit. Commonly used for many of the citrus cultivars.
Bitter Orange (Citrus aurantium)
This rootstock was used for most of Australia's citrus species but has been found to be susceptible to tristeza virus. If you live in an area that is free of the virus, it's a great rootstock that is very cold and heat-tolerant and produces excellent quality lemons and limes.
Trifoliate Orange (Poncirus trifoliata)
If you live in sandy soils with the root-knot nematode present, the citrus you buy from your local nursery will probably be on this rootstock, which is nematode-resistant. Mostly used on lemons now, it will not perform well in arid areas with a high pH or tolerate any salt in the soil or in the water. This rootstock is usually used for pot-grown citrus and delivers very juicy high-quality fruit.
Troyer (Poncirus trifoliata hybrid x Citrus sinensis)
A tough number that is cold and salt-resistant and was used extensively as the rootstock for Meyer lemons in country areas where other rootstocks struggled. It is also moderately resistant to phytophthora. The fruit grown on this rootstock is apparently very juicy. Troyer rootstock is incompatible for the Eureka lemon.
Planting, watering and fertilising
Citrus trees need an open, sunny site, as the warmth builds up the sugars in the fruit. The more sun the better, with an ideal temperature of 20 °C to 32 °C. In cooler districts, the best time to plant your young citrus is from September to April – and never in winter. In more tropical or warmer areas you can plant all year round.
The biggest enemies to your citrus trees will be heavy clay soil and severe frosts. If you are unlucky enough to have both of these, I would only grow them in pots. It will save loss of moisture from your body from weeping and wailing. It's soul-destroying to see your lemon tree powering on with lots of new growth, only to be cut in its prime with blackened burnt leaves on the second consecutive week of –5 °C.
If you have sandy, gutless soil like much of Western Australia, you will need lots of soil amendments, wetting agents, mulch, liquid and granular fertiliser, perseverance and a strong belief in some higher order of being that keeps you positive for the first few years. You will need to create a well around the tree to capture and hold water.
(Continues...)
Excerpted from Sabrina's Juicy Little Book of Citrus by Sabrina Hahn, Naama Amram, Tracey Gibbs. Copyright © 2012 Sabrina Hahn. Excerpted by permission of Fremantle Press.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
Contents
Title Page,Copyright,
Introduction,
Propagation and care,
Citrus varieties for the home gardener,
Troubleshooting,
Extra bits,
Acknowledgements,
About Sabrina,