Are your plants hormonal?
Posted by Phytopath on May 27, 2010
Grrr...
There are three factors affecting plant growth:
- Signals from the environment
- Nutritional factors
- Hormonal signals
Hormones are chemical substances produced in small amounts in one tissue and transported to another tissue where they have an effect. (Most men of course would proclaim that hormones have a huge effect when they are referring to their partners)
They are chemical messengers which regulate growth.
There are five important hormones which are found in nearly all seed plants and these co-ordinate the growth of the plant as a whole.
Many of the effects of the external environment on development are mediated by the distribution of these hormones within the plant. They are;
- Auxin
- Cytokinins
- Gibberellins
- Abscisic acid
- Ethylene
Auxin was the first plant hormone to be discovered and it is manufactured in shoot tips, embryos, fruit and young leaves. Auxin promotes the elongation of shoot tissue cells. It is also the hormone involved in geotropic responses (curvature) of shoot tips to gravity.
In many plants the presence of auxin in the growing tip of the stem inhibits the growth of lateral buds below the apex. This phenomenon is called apical dominance. Removal of the growing tip, and thus the auxin, removes the inhibiting influence and the lower buds may sprout. That is why ‘pinching out’ the apical bud stimulates bushier growth in many ornamentals.
Application of artificial hormones containing auxin to cuttings will stimulate production of roots.
Development of fruit is stimulated by treatment of the flower with auxin. Treatment prior to pollination of the flower will produce seedless fruit.
Cytokinin stimulates cell division and its presence will stimulate the differentiation of vascular tissue (e.g. xylem). Buds which are inhibited by apical dominance may be ‘released’ by cytokinin. Cytokinin delays the ageing process and senescence in leaves. (I am surprised cosmetic chemists or scientists have not come up with an anti-aging cream containing cytokinin – perhaps because we are not plants)
Gibberellin is an important hormone in stem elongation (no comment here). Many dwarf plants are the result of diminished gibberellin in the stem. It also promotes bolting and rapid elongation of the stem. This occurs naturally in many plants which grow in a rosette form and produce a long flowering stalk. Gibberellin also promotes flowering in some long day plants, and also promotes pollen development.
Abscisic acid (ABA) stimulates the closure of leaf stomata. When a plant is under water stress and begins to wilt, abscisic acid is produced in the leaves, and closure of the stomata occurs quite rapidly in response. Abscisic acid also regulates leaf abscission.
Ethylene is a gas made in small quantities in plant tissue, which triggers the fruit ripening process. It is used to bring about the uniform ripening of bananas and control the flowering in pineapples. A rotten apple produces ethylene gas which causes nearby apples to rot. CO2 storage of apples prevents the ripening effect of ethylene.
So – are your plants hormonal?
Introduction to Eucalyptus
Posted by Phytopath on May 24, 2010
Eucalyptus
Australian forests (what is left of them) are made up of trees, mostly from the genus Eucalyptus.
The word Eucalyptus comes from the Greek Eu, meaning well and kalyptos meaning concealed, which describes the appearance of the developing flower and the fact that it is covered by a cap.
Eucalyptus species have been planted in many parts of the world, sometimes becoming problematic. There are over 500 species of Eucalyptus growing in Australia and prior to seed movement by Europeans only nine species were found growing outside of Australia, most of these occurred in New Guinea.
Four main characteristics are frequently used for identification of Eucalypts (gum trees). They are: bark, flowers, fruit and leaves.
The bark is usually described as smooth or rough. Within the rough category there is further distinction between stringy bark, iron bark, bloodwood, box and fibrous. The smooth barks can be described as having scribbles, flakes or ribbons.
Inflorescence characteristics are identified by the type and arrangement, the number of flowers and the peduncle. With unbranched (axillary and simple) inflorescence, the clusters develop on a single axillary peduncle and with branched (axillary and compound), the clusters occur on two or more peduncles arising from a rhachis. The third and less common type of inflorescence is called terminal and compound where a number of clusters develop in a branched arrangement at the tips of branches.
The peduncle itself can also be used in identifying certain species. They are described as simple or compound, stout or slender and round, elliptical, angular, flattened or strap-like.
Buds are comprised of three parts, the pedicel, hypanthium and operculum. The pedicel is either attached directly to the apex of the peduncle or each bud develops at the top of its own pedicel. The shape of the operculum, also used for identification, is described as beaked, conical, elongated or hemispherical and the length is either long or short.
The fruit is a capsule that is dry and woody, often called a gum nut. Fruit width is either small (narrower than 0.5 cm), medium (0.5 – 1.5 cm) or large (wider than 1.5 cm). The number of valves varies between species and there are the same number of fruit in a cluster as there are flower buds in a cluster.
Flower colour is red, pink, orange, yellow, greenish yellow, cream or white.
Leaves are often similar, only changing in length. The leaves are produced from buds that are not covered by a protective scale. Theses naked buds allow rapid growth and multiple stems unlike some Northern Hemisphere trees that have a protective leaf bud and only produce one set of branches each spring/summer.
The juvenile leaves are often arranged differently along the stem to that of the adult leaves. For example juvenile leaves can be opposite and adult leaves alternate, along the stem. The shape of the juvenile leaves can also be a characteristic of one species.
The leaves have a thick waxy cuticle to help prevent moisture loss and mature leaves hang down in a vertical position so only a small surface area is exposed to the hot midday sun.
One of the adaptations found in Eucalypts is the lignotuber, a special swollen structure at or near the base of the plant. It contains a mass of woody tissue with large food reserves and numerous dormant buds. The trees will sprout from these lignotubers if exposed to fire, drought or hard pruning. The Mallee Eucalypts develop the largest lignotubers and can be found producing many trunks from the same lignotuber.
The Eucalypt or gum tree can be seen by some to be a pest or nuisance but they provide food and shelter for native birds and animals. The hollows in the branches are home for 25% of Australian mammals and a large number of Australian birds.
They also provide shelter on farms and hardwood timber for building. They help prevent soil erosion and decrease soil salinity problems. Their recreational use is often overlooked, providing forests for camping, bird watching, bushwalking and just chilling out.
Gifts from the Garden
Posted by Phytopath on May 21, 2010
Gift basket
A garden can supply us with a wonderful array of gifts for ourselves or others.
If you grow flowers for picking, a fresh bunch of flowers and foliage can make someone’s day. Or perhaps you are a dab hand at dried flower arranging, or using dried flowers, foliage and fruit for decorating cards and boxes.
Then there is always fruit. Fresh fruit in a basket is not only for those in hospital. Mix fresh produce with jars of preserved produce or jam made from the same fruit and decorate the jars with some dried leaves from the same tree or shrub. Or you could candy the fruit, make cordial, syrup, liqueur (yum) or fruit flavoured vinegar. Cover an orange with cloves and some pretty ribbon to make a sweet smelling pomander to hang somewhere as a room freshener.
Even vegetables make good gifts. Fresh veg, pickles and preserves are all well received by thankful friends. Dried vegetables like gourds can be decorated and made into bird houses, bowls and just ….well… nice decorations. And cakes, yummy – carrot and walnut or zucchini and almond or anything else that takes your fancy. You could put together a gift basket containing fresh zucchini, zucchini cake, zucchini patties with a jar of fruit chutney and a packet of zucchini seed with a nice recipe attached. I chose zucchini because even growing just two plants; they seem to produce enough to feed the neighbourhood.
Pot plants are another great gift, simply gift wrap with a note card, or turn a plant into a ‘standard’ or a bonsai or topiary. Put two or three plants together that are used as an herbal remedy (e.g. calendula, yarrow and comfrey) with a recipe, how to make an herbal cream for cuts and bruises.
Another gift idea for an organic gardener is to make a basket containing some fresh garlic and chilli along with the recipe of how to make garlic and chilli spray.
Do you have friends that are interested in herbs or herb gardening? A variety of gifts can be made including: flavoured vinegar and oil, flavoured butter and sugar, herbal tea, edible wreaths, tussie mussie, bath bags, sleep pillow, pot pourri, seasonings, etc, etc.
If you have a creative mind, the list is endless of gifts you can make from things in the garden.
Culinary Salt Recipes
Basil Salt
Combine equal parts basil and rock salt
Chicken Salt
4 parts garlic
2 parts marjoram
2 parts thyme
1 part tarragon
4 parts rock salt (optional)
Fish Salt
2 parts fennel
1 part lemon thyme
6 parts marjoram
8 parts parsley
1 part oregano
Ten Gardening Tips
Posted by Phytopath on May 18, 2010
My apprentice
1. Always face an empty wheelbarrow in the direction of travel BEFORE you fill it up. It is much easier to move a heavy object forward, than try to manoeuvre its direction once loaded.
2. When designing vegetable beds, make them no wider than 900 mm (approx 3’) so you do not have to tread on the soil when planting, weeding and harvesting.
3. If you have already made your vegetable beds wider than 900 mm, place a flat paving stone or piece of hardwood timber, between the planting rows. Use these to step on so you don’t tread on the soil.
4. Grow quick growing vegetables like radish, between longer maturing vegetables, like cauliflower. The quick growing vegetables will be grown and harvested before the longer maturing varieties need the space. This is called inter-plating.
5. To prolong the life of lemons after harvest, store them in a plastic bag in the refrigerator.
6. After harvesting pumpkins, store them on their side in the sun for about three weeks, turning them regularly. They should then store for about 12 months.
7. To keep wooden handles on gardening implements in good condition, treat them twice per year with an equal mixture of Linseed oil and turpentine.
8. Remove the dead flower heads of annuals, shrubs and trees (if you can reach), to give a longer flowering season.
9. Bentonite, humus and swales help to ameliorate the problem of non-wetting soils.
10. When constructing garden steps, the tread should measure between 300 -450 mm and the rise should measure between 100 – 150 mm. This should make the steps feel comfortable to walk on.
Leafy Greens
Posted by Phytopath on May 14, 2010
Salad burnet
People are becoming more aware of health issues and are taking responsibility for their own health. As a result, there has been an increase in the consumption of salads.
Growing your own leafy greens can create a sense of satisfaction and supply you with an array of fresh daily produce.
When making your own salads, try mixing a few different varieties of salad greens and experiment with the combinations of flavours.
Some easy greens to start you off are: lettuce, baby endive, baby rocket, mibuna, mizuna, baby tatsoi, sorrel, salad burnet and even dandelion.
There are many different varieties of lettuce, some forming a heart and others with loose heads.
The best known and most widely used lettuce in Australia is ‘Iceburg’ (called ‘crisphead’ in the US). It doesn’t really have a taste (As a child, I remember sprinkling sugar on the leaves and rolling them up, just to give them some flavour) but it is crunchy. It is known as a hearting lettuce and is dense and firm. It has good keeping qualities and is useful for shredding or cutting into wedges.
Butter lettuce is a loose head variety with soft leaves that have a buttery feel and a mild taste. Mignonette is another variety of butter lettuce with tightly furled leaves, green or red-ish in colour and a slightly bitter flavour.
Loose leafed varieties include coral, which is available in green and red, and has leaves with tight frilly edges and a sharp flavour, and oakleaf, whose leaves can be harvested individually as needed, also in green and red.
Let’s not forget ‘cos’ lettuce, which is traditionally used in Caesar salad. It is also known as ‘romaine’ and has stiff, upright, elongated leaves, the inner ones being much sweeter than the outer leaves.
Endive, or curly endive (also called frisee) is a member of the chicory family. It is a loose headed variety with frizzy, curly leaves and a mild, bitter taste.
Radicchio, also known as Italian chicory is available as both loose leafed and hearted. It has a bitter taste that ranges in intensity depending on season and maturity. Use sparingly.
Rocket, called arugula in the US, has a peppery flavour that intensifies as the plant matures. Baby rocket has a milder flavour and wild rocket has a nuttier taste than the flat leafed variety.
Mizuna, also known as Japanese mustard, has long serrated leaves with a sweet earthy flavour. We grew so much of this at work a few years ago that one of our students took a truckload (mild exaggeration) home for her chef husband to be creative with. The result was, every student in the class received a jar full of mizuna pesto. It was scrumptious.
Salad burnet is a favourite of mine, not just because it tastes nice but also because it is a perennial in my climate and I don’t have to replant it every year. The leaves are small and compound and taste like cucumber. This gives you the opportunity to have a cucumber taste in your sandwiches through winter when cucumbers are not normally grown.
Dandelion is often overlooked because it is considered a weed, but it is a very useful plant. All parts of the plant are edible, so leaves and flowers can be used in a salad.
Growing your own is as simple as preparing a bed or pot for your plants and putting in some seed. Remember not to sow the seed too deep or they will not germinate and keep them well watered for fast growth and continuous harvest.
Some workable combinations are:
Rocket, pear and parmesan
Radicchio, pear and walnut
Mustard cress and pine nut
Experiment and let me know your results.
Soil is Not Dirt
Posted by Phytopath on May 10, 2010
Red-brown Earth
One thing that I find mildly annoying is calling soil, dirt.
Dirt is what politicians put on each other, soil is a valuable resource.
We use soil to grow food, grow timber for building materials, make beautiful pottery and to build mud brick homes.
Soil health is very important to our own health. Food that is nutrient dense is grown in a soil that is very much alive and brimming with soil microbes.
When we talk about plant nutrition we often think of feeding the plant with major and minor nutrient elements such as the big three; nitrogen, phosphorus and potassium.
What we really should be thinking about is feeding the soil. If we do this, the plants will thrive.
A healthy organic soil has the ability to ‘hold’ on to nutrient elements until the plant requires them. Humus, the end product of decomposed organic matter, has a negative ionic charge that attracts and holds any nutrient element that has a positive ionic charge (called cations).
Think of a magnet that has a north pole one end and a south pole the other end. Now instead of thinking north and south poles, change that to positive and negative. When you place two negative magnets together they will repel and the same happens for two positive magnets. But place a negative and a positive together and they will be attracted to each other and form a bond.
The interesting thing is, organic matter and clay particles have a negative charge. That is super special if you want your soil to be nutrient rich. The ability of the soil to hold on to these nutrients is called the cation exchange capacity.
The plant roots can then treat the soil almost like a supermarket, and go shopping for the nutrients they require for growth. The plant roots do not just take the nutrients they want, they pay for them in the form of bartering. The plant will take up a nutrient in exchange for a nutrient that it already has in its system. Cool hey?
What is also interesting is that plants really don’t care whether the nutrients are in organic form or chemical form. Nitrogen will always be nitrogen and calcium will always be calcium, but if you supply the nutrients (fertilizer) in an organic form, then you are feeding the soil and the myriad of soil micro-organisms. This of course is great for the life of the soil.
To be continued……..
Camellia
Posted by Phytopath on May 7, 2010
Paradise Pearl
I recently purchased a Camellia and at the time was undecided whether to buy a sasanqua or japonica. I eventually bought the sasanqua hybrid, because I liked the flowers, but it was also the best choice for my climate.
Camellia is from the Family Theaceae and there are currently over 300 named species.
The three most commonly grown camellias in Australia are C. japonica, C. sasanqua and C. reticulata. Of course there are also many hybrids available.
The greatest number of species occur in Southern China but they are also found growing in Japan and Indochina.
All species are evergreen shrubs or small trees and most have flowers in the white, pink and red range of colours, although there are some with flowers that are pale yellow to bronze in colour.
Most of the new releases have been deliberately hybridized and are no longer straight species of C. japonica, C. sasanqua or C. reticulata. Camellia japonica is parent to thousands of these cultivars and hybrids but few have any perfume.
Camellias grow best in well-drained, slightly acidic soil that is moist and enriched with organic matter. Good drainage is important because Camellias are susceptible to Phytopthora (root rot), but moist soil is also important for good growth.
The addition of organic matter can help with this because it has the capacity to hold water for later use by the plant.
Most Camellias are moderately frost hardy although some species are frost tender.
They enjoy a mild, humid climate and grow best in part shade. This of course will depend on local conditions. Camellia sasanqua is more sun tolerant than the others but morning sun is preferable to afternoon sun.
For longer lasting flowers and good looking foliage, semi shade is best.
Camellia sasanqua is a vigorous grower and the leaves are small and glossy. Because of the size of the leaves, this camellia is a good choice for formal hedging. The plant will respond well to pruning and the small leaves create a bushy appearance.
If you do not want to create a hedge then there is really no need for pruning but a light trim after flowering won’t hurt.
The sasanqua camellia produces an abundance of flower buds that open continually over a long period from early autumn until mid winter. It will flower in shade, semi-shade or full sun (not harsh) and most flowers have a fragrance. There are varieties with single or semi-double flowers and many seeds are produced.
Camellia japonica found growing in its natural habitat usually has red, five- petalled flowers that are quite small. The current garden variety of C. japonica has been through 300 years of careful selection. The Chinese favoured and selected plants with double flowers and the Japanese selected plants with single flowers.
Currently, cultivars are classified according to flower size and form. The smallest being miniatures with flowers under 6 cm (2½”), and then small, medium, medium-large, large and very large (sounds like an advertisement for clothing). The very large flowers are over 12 cm (5”).
The forms of flower are described as single, semi-double, anemone-form, informal double or peony-form, rose-form double and formal double. (It’s getting quite complicated and sounds to me like departments in a corporation). Would you like fries with that?
The japonica’s may need thinning if the foliage becomes very dense. Remove any branches that are crossing over and rubbing, and thin out the centre to allow more air to circulate and light to penetrate. The best time to prune is after flowering but you can also prune in early autumn. Wait until the flower buds have formed and then remove any stems that have no buds.
Camellia reticulata is more upright in growth habit than C. japonica and the leaves are large and leathery. They bloom from late winter to mid-spring and have some of the largest flowers of the camellia’s.
Below is a short list of the common camellia varieties and their respective growing zones.
Camellia japonica, zone 5 – 10
Camellia sasanqua, zone 9 – 11
Camellia reticulata, zone 7 – 10
Camellia oleifera, zone 7 – 10 (grown for the seed oil used in cooking and cosmetics)
Camellia sinensis, zone 9 – 11 (Tea)
What has been your experience growing Camellias?
By the way, this is my third attempt.
Plant Profile – Parsley
Posted by Phytopath on May 5, 2010
Parsley
Family: Apiaceae (formerly Umbelliferae)
Genus: Petroselinum
species: crispum var. crispum
Common name: curled parsley
Varieties: P. crispum var. neopolitanum (Italian parsley)
P. crispum var. tuberosum syn. P. sativum (Hamburg parsley)
Origin: Europe and Western Asia
Plant description: biennial, 25-75 cm tall (depending on variety). Leaves divided pinnately into feather like sections, lower leaves are ternately decompound with wedge-shaped segments deeply cut into lobes. Flowers are white or greenish-white and very small with five petals and five stamens on long peduncles in terminal axillary umbels. The fruit is grey-brown in colour, ovoid in shape, ribbed and up to 2 mm in diameter.
Propagation: soak seed in warm water overnight and sow in spring when soil temperatures rise above 10°C.
Soil: moderately rich, friable, moist but well-drained.
Aspect/climate: full sun to partial shade.
Cultivation: new plants need to be planted each year for a constant supply.
Pests & Diseases: may be attacked by carrot weevils, parsley worms or nematodes (in sandy soil), also susceptible to crown rot.
Parts used: leaves, roots, seeds.
Harvesting & storage: easily dried in an oven, pre-heated to 120°C. Place the leaves on a tray in the oven after turning the heat off and turn a few times while the oven has residual heat but is slowly cooling. After 15-20 minutes the parsley should be crisp and dry, then store it in an airtight container in a cool dark place. Fresh sprays can be wrapped in foil and frozen.
Flavour: mild.
Properties/actions: carminative, diuretic, antiseptic, emmenagogue. The root has laxative properties. The plant contains calcium, potassium, magnesium, iron, phosphorus, vitamins A and C and several B vitamins.
Weight: per tsp (5ml) of whole dried chopped leaves = 0.3g
Used in: tussie mussies
bouquet garni (with thyme, marjoram, bay leaves)
fines herbs (with chervil, chives, tarragon)
mixed herbs
Italian herbs
Chermoula spice mix (with coriander leaves, onion, cumin, cayenne)
Complements: savoury dishes
seasoning mixes and salts
egg dishes
mashed potato
tabouleh
soup
pasta dishes
sauces for fish and poultry
Traditional use: wreaths of parsley were used for adorning the tombs of the dead. It was also worn by bridesmaids at weddings. Parsley also had a reputation for being an effective deodorizer and breath freshener and used for the relief of pain in the stomach. It was also used to repel head lice.
Warning: not to be taken in large quantities or in seed form during pregnancy.
Parsley Recipes
Culinary: Green Goddess dressing
150 ml mayonnaise
142 ml sour cream
30 ml (2 tbsp) chopped fresh parsley
30 ml (2 tbsp) chopped fresh chives
30 ml (2 tbsp) cider vinegar
4 anchovy fillets, finely chopped
Salt and freshly ground black pepper
Mix all the ingredients together and season well. Allow to stand for several hours before using. It should store for up to 4 days in a screw-top jar in the refrigerator.
Makes about 300 ml.
Cosmetic: Parsley skin freshener
½ cup chopped parsley
1 cup boiling water
Place the parsley in a ceramic bowl and pour the boiling water over the herb. Allow the mixture to cool completely, then strain and pour into a clean container.
To use: apply to the skin using a clean cotton ball.
Medicinal: Parsley Tea
3 sprigs fresh parsley
1 cup boiling water
Steep the parsley in the boiling water for 10 minutes. It is good as an overall tonic and assists the bladder, kidneys and liver. It has a cleansing effect.
