Tuesday, 29 March 2016

Organic Approach to Pest Control Part VI - Citrus

Green lacewing - a beneficial bug

A few guidelines for good citrus health with some organic remedies:

Practice good hygiene by never leaving fruit to rot on the ground.

Keep an eye out for Bronze Orange Bugs - they often give away their presence by their foul smell. The young pale green nymphs appear in winter, their colour changing through orange to bronze as they grow into adults. They can be serious pests - causing flower and fruit drop by sucking on the stalks. Hand removal is possible (although it is recommended to wear eye protection, long sleeves and gloves) by placing them into a bucket of hot water with some dish washing liquid.

The adult spined citrus bug has projecting horns on either side of its head, the young change colour from yellow through orange and finally to green. They attack the fruit, causing shedding of the young fruit and dry patches in mature fruit - control by hand picking as above.

Collar Rot is a soil fungus that attacks the tree trunk at ground level and if left untreated it can kill the tree. The first signs of Collar Rot are splitting, oozing bark and yellowing foliage. Cutting the bark back with a sharp knife or chisel until undamaged bark is reached is the main treatment. Avoid wetting the trunk when watering and keep mulch away from the trunk. Make sure that there is good air circulation and excellent soil drainage.

Citrus Gall Wasp is something we all need to keep an eye out for. Prune out any affected twigs and branches before August and either burn or double bag and place in Council red bin. If there are any tiny holes in the gall - that's it folks, they have already hatched!!

Scab is a fungal disease that affects young fruit (especially lemons) causing raised light brown corky scabs on the surface of the fruit. Good hygiene and improving air circulation will help this problem.

Citrus Leaf Miner causes ugly distorted leaves with silvery trails in the leaf tissue, especially in spring and summer. Eco Oil is a non-toxic control, spray when new growth is about 1cm long and reapply every 2-3 weeks.

Scale are sap-sucking insects with small, round shells and are often found along the veins of leaves and the stems of plants. They look like small bumps and can be mistaken for part of the plant, as adults do not move. Eggs are laid under the scale or white louse scale can seriously damage or kill young citrus trees. To control treat with Lime Sulphur spray in winter. Other scale outbreaks can be controlled with Eco Oil, which works by smothering the scale. Some soft scales, including white wax scale and black scale, secrete large amounts of 'honeydew' which causes problems by sticking to the lower leaves where it is fed on by a fungus called Black sooty mould. Honeydew also attracts ants, which feed on it. The ants can 'farm' the scale, protect them from predators, so the first step is always control any ants, as without their protection the abundance of natural enemies in an organic garden will usually be able to keep scales under control. Keep ants out of your trees by banding the trunks with horticultural glue. Prune any low branches that are touching the ground and make sure that tall stems of grass aren't providing a 'ladder' for the ants. You can read more on scale here.

Improving the environment for the natural predators of scale is a long-term strategy that will eventually pay off. Natural enemies of scale include lady beetles, lacewings, spiders and tiny parasitoid wasps. Many beneficial insects that feed on garden pests need nectar and pollen for food during part of their life cycle. Growing a year-round supply of suitable flowers such as Green Harvest's 'Good Bug Mix' which will maintain beneficial insect populations throughout the year. This mix contains colourful re-seeding annual and perennial flowers including red clover, alyssum, cosmos, marigolds, Queen Anne's Lace, buckwheat, lucerne, dill caraway, coriander and phacelia and gypsophila. There will be blooms for much of the year, providing nectar, pollen and habitat for wild and introduced beneficial insects, such as predatory mites and tiny micro wasps. ladybirds, lacewings, hoverflies, tachnid flies and predatory beetles. These insects or 'good bugs' are generally small with correspondingly small mouthparts, so they are only able to feed on particular flowers with suitable attributes. By providing a plentiful food supply these 'good bugs' can live longer and reproduce more. Small insect-eating birds are also helpful in controlling scale; attract them by providing safe nest sites and a constant supply of water.

Black sooty mould is a fungus that feeds on honeydew. Honeydew is produced by a range of insects including aphid, scale, mealybug and planthopper. Sooty moulds make a plant look really unattractive and interferes with photosynthesis. To get rid of the sooty mould you need to address the pest problem. Once you have that under control and they are no longer producing the honeydew, the sooty mould will dry up and flake off.

Spider mite there are some easy things you can do that will have a big impact on spider mite numbers. Try a high pressure hosing in the early morning, three days in a row. An unlikely pest control device is a hand held vacuum cleaner - after vacuuming, tip the contents immediately into a plastic bag and freeze for a couple of hours. You can control whiteflies doing this as well. Pruning back affected plants and removing infested leaves will reduce pest numbers. 

Mealybug treat with Eco-oil, horticultural glues, natrasoap or pyrethrum. But first address the issue of the ants - one comes with the other usually.

Aphids are sucking insects that have a large number of natural enemies including some of the beneficial insects mentioned above. They tend to be a problem where the use of pesticides is wiping out the natural enemies or at times of the year when natural enemies are not present in large numbers.

Whitefly are small white moth-like flies. Eggs are laid on the undersides of leaves and hatch in about 8 days. Both newly hatched 'crawlers' and adults feed by sucking the sap from the underside of the leaf. They also excrete 'honeydew' which causes problems with black sooty mould. Vacuming in the early morning and freezing for some hours seems to be quite effective. Companion planting with nasturtiums can often help.

Snails - start with a garden clean up to reduce snails and slug breeding sites. Remove any old wooden boards and other garden rubbish. Check any pot rims and around drains and retaining walls. Have a bucket of soapy water at the ready and drop them in as you find them. Handpicking, will over time, greatly reduce the number of snails - it is less effective for slugs. A really good way is to give financial reward to children and make it a fun activity by torchlight to collect as many snails as possible. Of course, if you have ducks snails will most probably not be a problem for you!

Wednesday, 23 March 2016

President's Message - March 2016

Firstly, can I say a very big thank you to Bob Tarry for standing in for me whilst I'm in Sydney for the Royal Easter Show. I note from the meeting minutes that plenty of ground was covered as usual.

Particularly important for us gardeners was the presentation by Marg Murray from the Friends of the Botanic Garden who spoke about the current review of the structure and management of the Garden. The Garden Club and the Friends have worked closely over the years and I'll be getting in touch with Marg to discuss how our Club might be able to help- out in putting forward its views on the review draft outcomes.

I've read the draft report, which is available on the Coffs Harbour City Council website, and there are some concerning aspects that I'll discuss with Marg before preparing a response on our Club's behalf. Responses are due in by 6 April, and although time is short, I really encourage you all to have a look at the draft report and perhaps put in your own personal submission as you see fit.

On a happier note, the Sydney Royal Flower & Garden Show is quite something to behold this year. We focussed the 2016 Show around the theme 'Art in Bloom', and so in addition to all the dahlias, roses, Australian natives, cacti, orchids, carnivorous plants, potted plants, bonsai, African violets and fruit and vegetables that people are exhibiting, we have a truly fantastic display of outstanding floral art from some of the Australia's best exponents. Their exhibits have been judged by a gentleman from Germany by the name of Gregor Lersch, who is an extremely fine, internationally acclaimed floral artist himself. I'll try to get some photos to show you at a meeting later in the year.

Editor's Note: Gregor Lersch has written many books on floral craftsmanship a link can be found on our facebook page.

Tuesday, 22 March 2016

Organic Approach to Pest Control - Part V Pyrethrum

Pyrethrum is an extract from chrysanthemum (Tanacetum cinerariifolium). It is one of the oldest pesticides known, and is also the strongest insecticide allowed under organic standards guidelines. Made from died flowers, pyrethrum insecticides are known for their fast knock-down of unwanted insects. Insects are typically paralyzed as soon as they come into contact so it is often used in wasp sprays (nothing worse than a cranky wasp). 

Pyrethrum insecticides are highly toxic to bees and other beneficial insects as well as fish so really it should be treated as a last case call in control of problem ants, aphids, caterpillars, whitefly and thrips.

Products often contain piperonyl butoxide for added effectiveness and are available as Beat-A Bug Naturally (Richgro), Nature's Way Bug Gun (Yates) and Pyrethrum Insect Killer (Kendon)

These products are broken down by sunlight so are best applied later in the day when light is less intense and when susceptible non-target insects have finished foraging for the day.

Please read instructions and guidelines thoroughly and pay particular attention to withholding period.

Monday, 21 March 2016

Sub-tropical Presentation from Gavin - Anthuriums

At the March meeting Gavin gave a presentation on Anthurium - Flamingo Flower.

Anthurium is a tropical plant native to Central and South America containing a thousand different species. Some are grown for their foliage, others for their flowers.

Leaves can reach a metre long or can be as small as 10cm. They also vary in shape but are mostly in the shape of a heart.                 

The most commonly cultivated Anthuriums are the Flamingo flower varieties which consist of two species but the flowers have many different colours. The colourful part of the flower is actually a bract which is a modified leaf. The real flowers are on the stalk which sticks up from the back of the bract.

Flamingo flowers are very common as a house plant and just about every nursery sells them.

They are perfect for pots both indoors and out but are also good planted in the garden as far South as Sydney in a shady spot. They will burn if in full sun.

Flamingo flowers are very compact growers, rarely getting larger than two feet.

They love rich, well-drained soil with plenty of water and in good growing conditions, they will flower constantly and brighten up a dark spot in the garden. 

So, if you are looking for a tropical plant that can flower all year round and give bright colour, then you can't go past an Anthurium.

Thank you Gavin for a fantastic presentation which generated lots of comments from the members.

Sunday, 20 March 2016

These images were taken at the first Dahlia session at the 2016 Sydney Royal Easter Show.

Saturday, 19 March 2016

Jane's Gardeners' Diary - March 2016

Crepe Myrtle - Species lagerstroemia 

At the March meeting Jane gave a presentation on this popular garden shrub/tree which is not only grown for its frothy crepe-like, massed flowers but its beautiful smooth colourful trunk and branches AND the stunning leaf colour in Autumn. To cap it all off, this species grows well here on the Coffs Coast!

Crepe Myrtle - lagerstroemia 'nivea grassi'

Summary:  A small tree perfect for suburban gardens. Believed to have originated in China, it is a tree for all seasons. In summer it provides vibrant flowers, which have a texture like crepe fabric, and last for up to three months, and in autumn it provides great leaf colour in shades of yellow, orange and scarlet.

Bark: This tree also has incredible bark, which looks magical in winter when low light hits the bare branches. These trees also get better with age, as the trunk develops a wonderful gnarled appearance, and the bark exfoliates in summer to give a gorgeous mottled look with patches of pink, grey and brown. 

Environment and Care: Crepe Myrtles thrive in a warm, dry climate with long summers and tolerate cold winters while they're dormant. It's a fairly versatile tree, adapting to coastal situations and dry conditions. The only thing it dislikes is wet feet. Crepe Myrtles bloom on the current season's growth so pruning isn't strictly necessary. Byut not pruning will result in a mass display of small flowers, so encourage large flowering heads by cutting back the main branches in winter. 


Crepe myrtles can be grown as:

  • Standard
  • Miniature
  • Low-growing spreading plant
  • small shrub
  • small tree
  • large tree

Indian Summer Range - Langerstroemia indica x L. fauriei

The Indian Summer range has been specially bred to resist powdery mildew, a fungal disease that can be seen on some older crepe myrtle varieties.

Each cultivar is named after an American Indian tribe, and they range in size from around 3-6m (10-18') fully grown.

'Acoma' has white flowers and a weeping habit. Height to 3m (10').

'Tonto' has rich pink flowers. Height to 3m (10').

'Zuni' has mauve flowers. Height to 3m (10').

'Sioux' has carmine pink flowers. Height to 4m (12').

'Yuma' has pale pink flowers. Height to 4m (12').

'Tuscarora' has rose red flowers. Height to 6m (18').

'Natchez' has white flowers. Height to 6m (18').

Pruning (one opinion)

Crepe myrtles can be heavily pruned in winter to encourage the development of long, arching branches of flowers.

However, the downside of this annual pruning is that it creates an ugly, butchered looking plant.

Left unpruned, crepe myrtles develop a naturally appealing shape and will flower well regardless. If a shrub is preferred, plant one of the new, smaller varieties, rather than pruning every year to keep a tree down to shrub size.

Pruning (another opinion)

Step 1: Prune small sprouts at bottom of the tree first. These are called 'suckers'. Left untrimmed, these will give your crepe myrtle a bush appearance. Suckers can be pulled out when they first sprout or trimmed with a hand pruner. Leave the large, healthy thick trunks to keep growing taller and stronger.

Step 2: Cut side branches. Prune any branches coming out of the side of the trunk up to about halfway up the trunk. This is called limbing-up, and helps the tree retain an attractive shape. For younger trees that you are starting to shape, prune the small limbs from the ground up, leaving only the 3-5 strongest limbs.

Remove smaller branches that are growing horizontally or toward the inside of the tree.

Step 3: Prune out dead and crossing branches. You can use hand pruners for small, thin branches that you can reach, loppers for branches that are more than 12mm (1/2 inch) thick, or a [pole pruner for thicker or taller branches. Cut branches that are growing at an angle or that detract from the shape you are trying to achieve.

Step 4: Cut long or arching branches back to where they are no more than 12mm (1/2 inch) in diameter. Branches that are too thin will still bloom, but they will not be able to bear the weight of the blooms and will droop or break. If you/re cutting a branch back to the trunk, cut flush with the trunk instead of leaving a stub.

Use loppers for lower branches or pole pruners for the tall ones out of reach.

It is not necessary to cut off seed pods. It won't affect blooming.


Thank you Jane D. for a tremendous presentation.

Tuesday, 15 March 2016

Flowers 'For the Vase'

Flowers can say it all - 'Get Well', 'Thank you', 'I'm sorry', 'Thinking of you' etc etc these sentiments are expressed eloquently just by extending a blooming bundle of flowers.

In this post there will be mention of cutting, preparation, storing, day-to-day care of cut flowers and examples of some of the best flowers for the vase. If we grow these flowers it is a simple matter of wandering through our gardens and picking flowers either to give away or for our home - nothing is more welcoming than a vase of flowers (perhaps baking bread gets the tick too!).

Lets assume you have flowers in your garden for picking. Equipment you will need:

  • clean and sharp secateurs/knife
  • a meticulously clean bucket filled to about 1/4 full of warm water - by using warm water in your bucket, the water is allowed to enter the stem more rapidly. 
  • spray bottle of metho/spirits to spray secateurs between plants 
From the outset your blooms have to be treated with respect and the first way is by 'conditioning'. This will make sure that flowers and foliage last for the maximum time - one of the most common causes of wilting in cut flowers and foliage is the presence of an air-lock in the stem. This air-lock usually forms as the flower is cut when atmospheric pressure forces air into the water ducts of the stem in which there is normally a partial vacuum. So it is best if flowers cut from the garden are placed into the bucket immediately, finer bloom preparation details eg removal of leaves etc can be done later. 

To prevent diseases being transferred from one plant to another it is best to spray your cutting instrument between plants with metho.

The optimum time for cutting flowers is in the early morning or late evening. This is when flowers have the maximum amount of water in their stems and they will condition more readily. 

Once you have picked all the material you want for your arrangement, vase or bouquet take the time to complete the preparation of your flowers by: 

  1. Making sure that all the lower leaves are removed as any leaves left under water will quickly begin to rot and cause a build-up of bacteria which will clog the stem ends, preventing the uptake of water and also making the water smell foul. 
  2. Trim 1.5-2cm off all stem ends at a sharp angle, thus exposing more of the central area of the stem (known as the xylem tissue) which is responsible for the uptake of water and they don't sit 'flat bottomed' in the vase hindering the uptake of water.
  3. Flowers and foliages should remain in the water for at least two or three hours (or overnight) before arranging them. 

One of the biggest problems people have with cut flowers (either home grown or commercial) is that they don't seem to last. This most probably has got absolutely nothing to do with the flowers but everything about the vase that they are put into! Bacteria can live on for months in a dry vase so it is crucial that you clean your vases with soap and hot water with a few drops of bleach added.  

You can tell if commercial flowers are reasonably fresh by how perky they are. If there are any wilted flowers, wilted, yellow or brown leaves then it'd be a fair bet to say that they are really not a good buy. The leaves should be crisp and take a really close look at the centre of the flower - is it bright or faded? With some flowers you can gently pinch them to see how firm they are, if soft these would be another lot to pass by.

Don't let your purchased blooms sit is a ragingly hot vehicle without water for long - make your flower purchase the last thing that is done before you head on home. 

When you get your cut flowers home, remove all the packaging and re-cut the stems as described in 2. above. Be sure to remove any foliage that will be in or submerged under the water. 

Mix your packet containing flower preservative that accompanies your purchase with water. Choose a spot in your home that is out of direct sunlight, heat and away from the fruit bowl as fruit produces ethylene which cases cut flowers to die prematurely and condition for a couple of hours or overnight. 

A home made flower preservative:

2 Tablespoons lemon juice
1 Tablespoon sugar
1/2 Tablespoon bleach
1 litre of tepid water 

Change water in vases every 4th day.

Popular Fresh Cut Flowers:

Chrysanthemum without a doubt make the longest lasting, inexpensive cut flower list. There are just so many varieties with different forms, shapes and colours to choose from. They can last up to 20 days in a vase with care, so as far as value for $ goes this one ticks the box!

Dianthus (including Carnations, Pinks and Sweet Williams) are a rather under-valued flower. These flowers can last up to 21 days in a vase and are perhaps some of the best known of all cut flowers.  They also come in many different colours and forms, from mini to super large blooms. In the garden regular cutting will ensure a long flowering season. Avoid direct light as they will fade quickly in an arrangement. Carnations and pinks should have their stems cut between the node or joint, as they cannot take up water if cut or broken on the node.

are a lovely delicate looking flower that can easily live up to 14 days in water. Their colours are mainly from the pastel palette and just gorgeous. Be mindful that the leaves when purchasing must be crisp, otherwise you won't get the longevity you'd prefer.

Alstroemeria grow excellently here on the Coffs Coast so might be worth planting up some bulbs so there are plenty for the vase.

Roses - depending if they are perfumed or not has a huge impact on how long they will last in the vase. As a general rule of thumb a perfumed rose will not last as long as one without a fragrance. Those commercial Valentine Day roses are usually not perfumed, so they will last the trip home on the bus or train and still be good for a few days! Roses from the home garden tend to last longer as they are cut and put into water immediately. In addition to the sharp angled cut, the stem should be split for about 1cm.

will last in a vase from between 14 to 21 days - although I have had some home grown ones last for months! Trim orchid stems and change their water everyday, or at the very least every second day. Remove faded flowers and if you wish, individual flowers may be displayed by being floated in a decorative dish with fresh water.

Lily flowers can last up to 14 days in the vase. Remove the pollen pods to extend life and prevent staining - do this as soon as they open and the pollen matures. Pinch out spent blooms as they fade. Some lilies have the most amazing fragrance and such long stems they can look absolutely stunning in a tall vase.

Sweet peas will last from 3-7 days and are the ultimate 'cut and come again' flower. There are plenty of colours to choose from, but a good mix of shades makes the prettiest posies. It's important to cut Sweet Peas regularly to encourage more blooms. Cut the flowers just as the lowest bloom is opening. Never spray with water as this can disfigure the petals. 

Gladiolus  with a vase life of 7-10 days will always add that dramatic drama and height to flower arrangements. Cut gladiolus flowers just as the lowest two or three florets begin to open. 

Gladioli will always turn upwards at the tip if not arranged vertically (for the botanically minded, this is a phenomenon called 'negative geotropism' whereby the stem tips always turn away from gravity. The roots are positively geotropic, therefore they will always head towards gravity!). One way to avoid this happening is to carefully pinch out the top few buds, as it is only these which are affected. Also if you want all the florets to open at once pinch out the top few florets - this of course will shorten the vase life but is often used for a particular floral display or competition.

Peonies have a vase life of 5-7 days however, there won't be many grown on the Coffs Coast! They are just the most amazing over-blown beautiful blooms. Just a few stems will create an impact either on their own or in an arrangement. 

Sunflowers every child's favourite with a vase life of around 10 days. Always cheery and so easy to grow (provided you can keep the birds away). Cut the stems just before the flowers fully open and strip the lower foliage from the stem leaving just a few leaves at the top to help fill out your arrangement or bouquet. It is best to pick in the early morning.

Tulips can last up to 7 days in a vase. Not too many of these are grown on the Coffs Coast but they herald in the changing season for us. Re-cut the stems under water to prevent air entering the stems. They are thirsty cut flowers so you'll need to keep the water topped up with them. The stems also 'grow' in the vase so are best put into a vase by themselves. Be mindful never to be tempted to place them in a vase with Daffodils as narcissus species exude a substance that prevents your tulips (and other cut flowers) from taking up water - this doesn't apply if using floral foam. It is said that if you put a couple of pennies into the water of tulips this will prevent them from getting the 'droops'.

Eucalyptus is fantastic in arrangements as it lasts for more than 21 days. It makes a fantastic filler for flower arrangements. Its attractive rounded leaves provide shape and texture that blends well. Florists use the juvenile foliage of Eucalyptus which is more rounded and attractive than that found on mature plants - why not grow your own to have a constant supply of immature stems for cutting?

Gypsophila another great filler with a vase life of up to 7 days. With its frothy haze of tiny flowers, it is a much loved flower for arrangements. Keep this flower well away from fruit bowls as it is particularly sensitive to ethylene given off by fruit and vegetables which will cause the flowers to deteriorate faster.

Hydrangeas are notoriously difficult to condition when very fresh. They benefit from boiling water treatment - add about 2.5cm of boiling water to a jug, place the stem ends in the water for around a minute. This will force out the air from the stems and allow better uptake of water. Take them out of the hot water, then re-cut the stem ends and put them into water up to their necks or immerse them completely overnight before arranging. 

 My Sister, Carmel is quite a dab hand at floral arranging and has a wonderful garden that she gets most of her material from. 

Pictured here are two recent arrangements. My apologies for the fuzzy photos.

It is amazing how we can surprise ourselves by taking a stroll through our gardens and picking the odd flower and foliage, conditioning them and creating a wonderful tribute to those flowers in the vase for our homes.