Archive | September 2012

The good earth

Sep27

In this post I really want to get down and dirty!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Some time back I was givingt a talk at a garden show in which the word “soil” was, not surprisingly, mentioned several times.  A young man in the audience interrupted me to ask what I meant by this word.  What exactly WAS soil, he asked.  For once in my life I was briefly speechless!  However, I answered his question and he responded by looking faintly disgusted.  “Oh”, he said, “You mean DIRT!”.  It turned out that he confused soil with potting mix, the only medium in which he had ever seen plants growing!

I realised then that the nursery and garden industry was in danger of losing touch with today’s younger gardeners.  So with this in mind, a few months later when addressing a gathering of horticultural writers and broadcasters from around the world, I stood at the podium and steadily trickled a jar full of soil on to the platform.  A dramatic gesture and one guaranteed to get attention.  My point was that the horticulture media in general, and by extension the gardening public, had become much too product-driven.  Under pressure from the manufacturers and distributors of chemicals and gardening products, we were all looking for a quick fix for every garden situation.  What’s more, the media was hard-pressed to keep up with the sheer number of new products (and plants for that matter, but that’s another topic!) being launched every month, as a result not giving these products the critical analysis vital to evaluating them on behalf of consumers . And the loser in all this was good, old-fashioned gardening practice.

The basis of such practice is, of course, the understanding and nurturing of our garden soil.

If your soil ain’t right, you just can’t have a good garden.  It’s as simple as that!

I’ve been thinking about this subject a lot, lately, because I’ve just completed a book on soil (Improving Your Soil – The Natural Way; you can read about it on this site – just click the My Books tab.

Most people find soil a boring subject but I’ve been fascinated by it every since studying soil science many years ago.  After all, this wonderful mix of decayed animal, vegetable and mineral matter, broken down from its component parts, is the growing medium that sustains all life.  One of the great wonders of Nature is the way in which plantlife has adapted to survive in every type of ground, from thin and apparently un-nutritious sand to hard shale to heavy clay.  I’ve often observed with fascination those plants that cling so tenaciously with their roots to an apparently impervious piece of rock, able to find sustenance where other plants just wouldn’t last five minutes!

However, in the home garden, we want to grow a whole range of things that are not especially adapted to difficult soil environments but instead need rich, deep loam in which to thrive.  These include trees, shrubs, flowers, vegetables, edible and medicinal herbs, and fruit.  It’s possible to grow all these things in shallow, poor soil or thick, sticky clay – at least for a while.  But they won’t last long!

Over years of advising gardeners, either in print or face-to-face at garden shows, I’ve been amazed at how little they understand the need for good soil.  When plants are sick or don’t thrive the tendency is to blame insect attack or disease or lack of gardening skills.  Sometimes it is one or all of those things in combination.  But more often it is a problem with the soil – indeed, plants are better able to survive insect attack, and rarely become diseased, in gardens where the soil is just right. 

Sandy soils cause all but the few plants evolved to tolerate them to grow slowly and poorly through lack of nutrition, moisture and a secure root environment.  Clay soils encourage root rot through clagging when wet and baking hard when dry, and the roots of small plants can’t penetrate them.  Rocky soils just don’t offer garden plants anything at all in the way of nutrition or safe anchorage.   So all these soil types need to be improved and adjusted to meet the needs of gardeners.  Even if your idea of a garden is just a lawn with a tree in the middle, it still won’t look good if your soil is poor.

A “good” garden soil should be a rich brown or reddish brown or black in color.  It should be crumbly in the hand, slightly damp but not soggy.  This is a sign of a soil which has good tilth”.  My dictionary rather uninspiringly defines “tilth” as “the physical condition of soil in relation to plant growth” but we gardeners know it is the best word to describe soil which has the perfect structure and texture so that the very feel of it in your hand gives you a thrill!  A soil with good tilth contains plenty of “humus” – decayed organic matter which builds up structure and nutritional value.  If you are very lucky, you live in an area where the soils are naturally lovely and loamy. But if you live where the natural soil is clay or sand or rock then you are going to have to do something about it.

And that’s what my new book is all about.  In easy steps it shows you how to gradually but thoroughly turn your clay, sandy or rocky soil into a growing medium of which to be proud, through the regular application of much, compost and other products applied in the right way and at the right time.

The good earth is only as good as you make it!  And it doesn’t cost the earth to do that, either!

…And NO – this isn’t me in the picture.  Just another of our good local gardeners who understands the value of regular mulching!

In praise of old Azaleas

Sep27

 

 

Good old favourite Alphonse Anderson

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

People often ask me, what are the best azaleas to grow?

I always tell them – go for the oldies!  Because where azaleas are concerned, the oldies really ARE the goodies, if what you want are big, strong, floriferous and reliable plants to fill a space or make a show.

In this regard, the old indica species azaleas such as “Alphonse Anderson”, “Alba Magna” and “Exquisite” still out-perform every other type.  They go on blooming year after year, decade after decade, and all they require is a bit of water in very dry weather, regular mulching with acidic stuff such as leaf mould or straw, and a good cut-back after flowering.

Of course, there are lots of lovely azalea varieties available today in all sorts of colors.  And when it comes to selecting varieties of indica, mollis or kurume much depends on your climate – as a general rule indicas are the best for warmer climates while the deciduous mollis and compact kurumes thrive only in cold or upland climates.  Azaleas have been so hybridized and  genetically mucked about that the range available in a garden centre can be bewildering, unless you have a definite color scheme in mind.

The faithful old tall-growing indicas already mentioned here don’t produce autumn flowers, as do so many of the newer hybrid varieties .  But though they only flower in spring (with occasional  – but rare – spot flowering throughout the year) they do produce a good show for several weeks.  And they are much less prone to petal blight and just plain dropping down dead than the newbies, where breeding seems to be aimed more at bringing out yet another flashy-flowered brief sensation rather than a vigorous plant.

Getting your soil right for azaleas

Sep27

Are your azaleas a sight for sore eyes this spring?  If not, you may need to improve your soil.

Azaleas need a rich, loamy, acid soil to thrive and flower well.  The only way you can achieve this is with lots of compost and mulch – and patience.

Step 1 – break up the surface of your existing soil and fork it over a bit, to open it up.

Step 2 – add heaps and heaps of compost.  If you don’t make this yourself, buy it in.  Or you can buy in a load of good soil – but that can be expensive.

Step 3 – test your soil for acidity.  This is measured on a scale of 1 – 14, with acid soils at the lower end of the scale, alkaline at the other and a neutral, balanced soil in the middle.  Azaleas like a soil acidity of 4 – 5.5 on the scale.  You can have your soil professionally tested or buy a kit from a garden centre – it’s easy to use.  If you can’t be bothered with any of this, just assume your soil needs acidifying and do this with…

Step 4 – mulch, using acid materials such as pine needles, shredded pine bark or leaf mould.  Mulch is NOT the same as compost – compost is the rich, soil-like product of mixing organic greenwaste and manure and heating it to a high temperature to break down these ingredients.  Added to your soil they enrich it and add essential nutrients.  Mulching with coarse, uncomposted materials improves the structure and texture of your soil and as it composts slowly, over time (much slower than pre-made compost) it also adds some nutrients.  Using compost and mulch together is the best and fastest way to improve soil, creating a growing environment for plant roots that is nutritious and able to retain moisture.

And that’s all there is to it.  Do this now, and keep on mulching regularly during the year and by next year you should have a soil that will grow perfect azaleas.  If you do, send me a photo!  Oh, and if you want to learn more about these lovely plants click on My Books on this website.

Excite your palate with a true-blue Aussie flavour

Sep27

Australian rainforest food plants are useful additions to home gardens anywhere in the world where the winters aren’t cold enough for snow or too low in rainfall.  They do best in tropical and sub-tropical climates but most will do surprisingly well in warm-temperate climates if given shelter from cold winds and hard frosts, and plenty of water during dry periods. Other than that, they are pretty tough plants that don’t need a lot of fussing.  And they do add some interesting flavors to your home-grown diet.

 

Their benefits include:  

1.     Human health – though the nutritional values of most of Australia’s edible plants are still little appreciated or understood, they undoubtedly possess not only recognised vitamins but also unique values that benefit health in this climate.  

2.     Garden health – by attracting a range of birds and various pollinators to the garden, they enrich the biodiversity values that are essential to a TRULY sustainable garden  

3.     Habitat restoration – if you live in Australia native food plants extend the natural vegetation linkages that are so vital to the sustainability of both plantlife and wildlife – how wonderful it would be to create a network of gardens and parks across the country enriched by plants that can feed both wildlife and humans!  

4.     Good looks – the rainforest species mentioned in this article are all attractive, garden-friendly plants that can be put to a variety of landscape uses – as single ornamentals, in shrubberies and buffer zones, as hedges, pot plants, street trees and feature plants in courtyards.  

 

Here is my selection of the Top Six rainforest plants for food and good garden behavior:

 

Davidson’s Plum (Davidsonia pruriens)   

 

Riberry (Syzygium luehmanni)

 

Lemon Myrtle (Backhousia citriodora)   

 

Illawarra Plum (Podocarpus elatus)   

 

Finger lime (Citrus australasica)   

 

Red Bopple Nut (Hicksbeachia pinnatifolia)   

 

You don’t actually need to give these plants any care after establishment; they’ll survive and even thrive.  But if you’re growing them for food, a bit of extra TLC will give you more and better fruit.

General cultivation tips: Improve soil at the planting site with compost; provide water in summer dry periods, fertilise young trees for improved yield (but never too much because  too much nitrogen can promote foliage growth over fruit production); prune to maintain manageable shape and size; control fruit fly (in the two plums), protect from weather extremes.  As many soils are deficient in calcium, it may help to add gypsum.  Spring is the best time to fertilise and a high potassium fertiliser will improve fruit development in nut and fruit trees.  

 

Davidson’s Plum   

Unripe Davidson’s plums growing from the trunk of the tree

 

 

 

 

 

 

 

 

 

 

 

The best of the two subspecies being cultivated, because it produces the largest and nicest fruit, is Davidsonia puriens var. puriens (the other is Davidsonia puriens var. jerseyana). This tree occurs naturally in northern New South Wales and tropical/sub-tropical Queensland.  It’s quite small – to about 8m – with attractive toothed foliage and colourful new growth.  Fruits can be as large as 6cm in diameter and are purplish black with reddish flesh. Very juicy but not very palatable because rather sour, so best if stewed with lots of sugar or honey. A dash of port or brandy does wonders to the flavour!  The plum makes excellent jam and wine, and is a useful extender in other fruit jams.  Fruit is produced mostly in summer (though sometimes both earlier and later) and in mature trees is very prolific.  Improved yield cultivars are now available.   

Cultivation: To improve fruit yield, cultivate the planting area by digging it over.  Add plenty of compost.  Plant in a position protected from wind and frost.   Light shade is best, though a position with direct morning sun will help boost fruit production and flavour. It doesn’t like too much competition from other trees nearby – this slows growth. Davidsonia has a high moisture requirement; like most south-east Queensland rainforest plants it can withstand long dry periods but will grow faster if water can be provided during drought. Beetles may defoliate the tree from time to time but it soon recovers – a much worse problem is fruit fly, so take whatever measures you prefer for this pest and pick fruit when still fairly green, so it can ripen indoors. Ripe fruit stores in the frig and the pulp can be frozen

Propagation: Fresh seed germinates easily.  Early growth is slow.

 

Riberry  (Syzygium leuhmannii)    

 

 

 

 

 

 

 

 

Above:  This is actually the fruit of Syzygium australe, closely related to the riberry and very similar in taste and texture

This ornamental lilly pilly bears lots of small, pear-shaped, pinkish-red fruits in summer.  It’s a big tree to 30 m and can be widespreading too, so needs lots of room.  It’s also fast-growing – the more water it has the faster it grows! It bears at an early age compared with most rainforest trees – about five years depending on conditions. When mature it’s very prolific.  The crisp, tart fruit is edible though not exciting. It makes a very good juice when boiled with a sugar syrup and also jam, sauce (like cranberry sauce) and chutney, either alone or with other fruit (choco and riberry chutney is good!).  I add it to fruit salads, or any type of salad, and use in a variety of dishes – curries, stir-fries, as a garnish. Also with apple and other fruit in pies. 

Cultivation:  Using cutting-grown stock and pruning regularly means you can keep this to a manageable shrub size – it makes an excellent hedge but DOES need frequent trimming. It’s not fussy about soil and will take temperatures down to zero – and can even recover from frost, though protection when young is advisable. Plant in sun or shade, though full sun means more and better fruit.  Improved (composted) soil will mean better fruit production and water retention, and maintaining an acidity level of around 5.6pH will assist nutrient take-up if you are fertilising your plants. Mulch well. I’ve found that good drainage is essential for healthy riberries and at the same time they like a lot of water (but not waterlogging).  They’re geared naturally to withstand dry periods in winter/spring but growth will slow or stop if this happens during summer – so water may need to be applied. Fertilise with a low-phosphorus formula in spring, when the temperature begins to rise and rainfall begins.  This is only necessary in the first couple of years to encourage growth. I just use compost and it seems to work well. Some commercial producers fertilise again in autumn.   

Prune young plants to encourage a multi-stemmed growth (up to 4); then again lightly each year after fruiting (more if it’s a hedge but remember heavy pruning will prevent a good fruit crop next time because fruit develops on each year’s mature growth).  If the tree grows too large, it will need a good cut back every few years, and this will be followed by reduced fruit production for the next few seasons.   

If you’re planting a hedge, seedlings should be about 2m apart – if planting an avenue of individual trees/shrubs space about 5m apart – depending on desired size at maturity.  Don’t plant too near drains, swimming pools or any buildings.   

The worst problem is a borer that gets into the ripening fruit. I don’t know a sustainable remedy for this – I’d try standard non-chemical remedies as for other fruit. Monitoring is crucial, and fruit should be picked immediately it ripens. Scale and sooty mould can also be a problem – natural oil remedies are the best remedy. 

Improved varieties – for size, flavor and seed reduction – are available.  Fruit stores quite well and can be frozen.  Fresh seed propagates quite easily but cutting-grown improved varieties are best.   

 

Lemon myrtle 

A wonderful plant; every garden should have one because it’s beautiful, easy to grow, useful and versatile. The leaves are the richest source of cineole in the world and useful as a biocide, should you want to go to the trouble of extracting the oil.  It has a real “lemonade” flavour that’s not as harsh as other lemon-flavoured plants and is particularly suited to Asian dishes. It’s also easier to grow, better-suited to predominantly warm and wet climates and not so prone to insect attack as lemon verbena or lemon balm. (But try growing your lemon myrtles with a lemon balm groundcover for a REAL lemony experience!) Some claim that planting this small tree in and especially around a food/herb garden keeps certain pests at bay – even if this is not valid, lemon myrtle makes an excellent ornamental herbal hedge plant if kept trimmed low and bushy. Use for anything in which you need a lemon flavor – it makes good lemonade if leaves are boiled with sugar and water; can be used for lemon-flavoured oil or vinegar; makes a delightfully fragrant tea and is perfect with fish – or in a gin and tonic! The leaf dries well.    

Cultivation: No need to do much except perhaps provide water during very long dry periods in summer. Tip prune regularly and trim lightly once a year in autumn to maintain a manageable shape and height – keep it as a shrub rather than a tree. Protect young plants from wind. Grow in shade or full sun; sunlight develops the leaf flavour. This is a decorative landscaping plant for feature shrub/tree, border planting, hedge, tub or courtyard.   

 

Illawarra Plum (Podocarpus elatus)  

This striking tree is a member of an ancient family of conifers that take us back to Gondwana. Though slender when young, it can grow pretty tall and wide.  In autumn and winter female trees produce a blue-black fruit to about 30mm diameter with the seed carried on the outside of the flesh at the opposite end to the stem. The fruit can be stewed like Davidson’s Plum, or used with other fruits to make jam, chutney and sauces. It tolerates most local soil conditions including alkaline (though it occurs naturally on acid soils), and is also tolerant of light frosts.  

Cultivation: As for Davidsonia but again don’t overdose with high nitrogen fertiliser after the first year or two (when you need to encourage growth).  Apply in early summer, rather than spring. This tree is a bit slow to start but gets away after the first 2 – 3 years.  It needs plenty of water during establishment and again during long, dry periods in summer.  As always, prune lightly after fruiting and tip prune after that to promote bushiness and keep size small. 

This is a tough plant that can be used for buffer plantings and is also a good timber tree.  You need to have at least one male plus a couple of female trees for pollination and fruit production.  Best to look for plants from good nurseries that clone their superior selections.  

 

Finger Lime (Citrus australasica) and Wild (or Round) Lime (Citrus australis)   

Finger limes grow as small, shrubby trees in Queensland coastal ranges and lowand forests. In summer and autumn (usually) they bear finger-shaped fruit up to 10cm long, with thin green or yellow skin and green-yellow pulp. A subspecies with pink to red-flesh and red to purple or even black skin (Citrus australasica var. sanguinea) also exists but is becoming very rare.  The grafted cultivar “Rainforest Pink Pearl”, now popular in cultivation, is bred from this – and is probably the best bet for home gardens because those from the wild take too long to bear – anything from 5 to 17 years!  

The fruits make excellent marmalade, drinks and tangy sauces, and can be used alone or with other fruits including as an extender with exotic citrus. They are delicious if pickled whole in brandy or any other liquor, like cumquats.  

The Round Lime occurs on the margins of rainforests and tolerates drier conditions.  Its fruit is round and looks rather like a small exotic lime, with a thick green-to-yellow skin and pale green pulp.   

Australian native limes are hardy trees and rather slow growing, especially at first – but well worth the effort because they are both tasty and ornamental. 

Cultivation: Like all citrus they bear best if given water, especially in dry periods.  A formulated citrus fertiliser seems to work well, applied in spring.  Or just use a rich compost with plenty of potash added, for fruit development.  Prune lightly in winter to open up trees and maintain height to no more than 4m.

 

Red Bopple Nut ( Hicksbeachia pinnatifolia)

This tree bears a really tasty nut rather like a macadamia.  It’s oval and bright red on the outside, containing an almond-sized kernel. Tree height is about 8m and can be kept smaller by light pruning; or made to develop several trunks if pruned when young (as with riberry).  Seed germinates easily but seedlings need quite a bit of care so buying plants from a rainforest nursery is the easier option. Plant in spring/summer only and give protection from wind.  

Cultivation: As for Davidsonia and macadamias.

Thirty best tropical foliage plants for colour

Sep27

 

 

 

 

 

 

 

 

I promised to post what are, in my experience, the 30 best plants for creating a colorful tropical foliage garden.  If you have a reasonably large garden you can team these plants with palms and/or other suitable trees to create a tropical effect – but if all you have is a small garden or courtyard then the plants on this list will light up your life with a touch of true jungle romance.  They are:

 

Acalypha

Alocasia

Begonia

Cordyline

Croton

Ctenanthe

Dracaena

Graptophyllum

Polyscias

Schefflera

Aglaeonema

Calathea

Coleus

Iresine

Maranta

Philodendron

Poinsettia

Pseuderanthemum

Spathiphyllum

Strobilanthes

Altern anethera

Anthurium

Aspidistra

Bromeliad

Dieffenbachia

Peperomia

Caladium

Syngonium

Pilea

Tamborine Dreaming

Sep27

I love the place I live and really do believe it’s one of the most beautiful places on earth – and I’ve seen a few of them. It’s also one of the best communities in which to live – a caring community in the best sense of the word with good medical and aged-care facilities and very little crime. It’s also a community that loves art, music and theatre. An easy place to celebrate life’ one that’s a bit tucked away from the hustle and hassle of the world and at the same time not too far from essential services and good shopping. So to tell the world about the place in which I live I have a second blog called Tamborine Dreaming – you’ll find it at tamborinedreamingdotcom.wordpress.com/

Cold comfort for tropical foliage

Sep27

Tropical foliage plants can catch cold!  Truly!  Though most of the plants that fall into this category originate in the true tropics where days are hot and humid and night temperatures don’t drop very low at any time of year, these plants are nowadays grown in a wider temperature range from the sub-tropics to sheltered warm-temperate gardens where there is a decided “down” season when temperatures drop.  In the southern hemisphere that may coincide with the “winter” dry season where special care is needed.

What’s more, though plants such as bromeliads and many orchids come from the tropic latitudes, they occur naturally at high altitudes where lower temperatures occur and constant cloud cover prevents sun warmth getting through.  So they can tolerate – indeed may well require – quite low temperatures at times.

So unless you lived on a tropic beach with very little climate variation all year round, read on!

The two conditions which can send tropical foliage plants – or tropical flowering plants for that matter – into oblivion are cold and drought.  As most warm climates have a season in which little or no rain falls (for example tropical northern Australia, parts of Central and northern South America, India and Africa) and where temperatures are low at night, some tropical foliage plants have developed strategies to deal with this – they go to ground.  Caladiums and tropical gingers both do this.  In fact many popular tropical foliage “indoor” plants have a dormancy period when neither, new stems, leaves or flowers are produced.  Spathiphyllums, anthuriums and calatheas do this – and so, among the flowering plants, do orchids.  This is vital to their life-cycle.

Anthuriums are very susceptible to cold and have a cool-season dormancy period

This “down” period renders the plant very vulnerable, especially where there is a marked change between summer and winter, high rainfall and low rainfall.  The two important considerations here are COLD and MOISTURE.

COLD

Isolated plants are lonely plants and, just as humans can survive cold by huddling together and using their combined body temperatures to create and share warmth, so can plants.  This is especially true of all those plants that we categorise as “tropical foliage” – the spathiphyllums, pileas, aspidistras, calatheas, marantas and others (for a full list go to  www.wix.com/jrlakemedia/ezibooks )- which come from crowded jungles.  If you are growing these plants in pots you can bring them indoors for the cool season.  If you are growing them in the garden then they must be massed together so temperature and moisture levels can be maintained at a higher level than the surrounding air.  This massed planting also helps keep the soil warm and moist.

Shade from palms and other trees will protect your tropical foliage plants from frost danger and wind exposure.  However morning sun is beneficial in cooler weather so create (or recreate)your planting scheme so that it faces the sunrise.  In sub-tropical and warm-temperate gardens use palms and briefly deciduous trees such as coral trees (erythrinas) and tabebuias as the overhead cover.  These will allow sufficient sunlight to filter through to the plants below in the cool season. DON’T plant your tropical foliage garden where it has no shelter from chill cool-season winds and exposure.

Cold, wet ground is the main killer of tropical foliage plants.  If these conditions are prolonged they will just curl up their leaves and die.  Root-rot fungal diseases thrive when soil is wet and cold and poorly drained. An early warning sign is moss growing on top of the hard-packed ground.  I have a corner of my garden that has heavy, poorly-drained soil that gets very soggy in winter when the sun only gets to it for an hour or so a day.  This combination is fatal to plants like cordylines and crotons and I’ve lost a few.  I now mulch, mulch, mulch to improve the soil and have dug a drain to channel excess water away from the planted area.

The other tropical plant assassins are, of course, frost or hail.  I get both where I live.  If you have sufficient overhead cover light frost shouldn’t be a problem; if on a frosty morning you notice some plants are affected hose them down quickly – though you probably won’t be able to save them. If you live where regular, severe frosts occur then you shouldn’t be growing these plants anyway! Hail shreds the leaves of fleshy foliage plants and there’s not much you can do about it except trim them back so new growth is encouraged – this being a plant’s natural response to disaster.  More dangerous is hail bruising of plant stems which can cause deep cell damage and leave the plant susceptible to fungal attack.  The same result will happen if the ice remains for any time piled up against the stem.  So after a hail storm push back the hailstones as fast as possible and water down the leaves and stems.  As with frost, an overhead canopy will protect plants below from the worst of a hailstorm.  Of course, hail is usually (but not always) a spring, summer or even autumn problem but I thought I’d include it here because it comes under the “cold” category as far as tender plants are concerned.

If you live in a sub-tropical, warm-temperate or fairly arid area some plants can give you a tropical appearance while still being able to take greater extremes of cold and low rainfall; they include:

Acalypha

Coleus

Cordyline

Croton

Ctenanthe

Dracaena

Philodendron (several types)

Poinsettia

Scheflera

Strobilanthes

MOISTURE

Don’t, don’t, DON’T over-water tropical foliage plants in the cool-season because few of them make any growth at this time and they can’t use the water – worse,  too much of it will cause root rot.  Yes, I know these are plants from high rainfall areas that thrive on heat and moisture and our instincts tell us to keep them soaked when the rain isn’t falling.  But nature gives them heavy monsoonal drenching alternating with dry periods, or in some equatorial areas a nightly drenching and a daily dry-out.  But they are not programmed to be waterlogged all the time.  So the only time you need to provide them with water is in prolonged dry periods, especially if it’s windy.  In such cases a light, misting spray twice a week is quite enough.

Caladiums need a lot of water in summer but die back and go underground in the cool season

Finally, DON’T fertilize your tropical foliage plants in winter (and that goes for those grown indoors as “house” plants, too!).  They won’t be able to make use of the extra nutrients anyway.  Save your efforts until late spring or just before the monsoon, depending on where you live,then give them a good dressing of blood-and-bone or chicken-poo pellets or well-made compost.

So that’s all there is to it.  When it comes to getting your tropical foliage plants through the cool-season dormancy period, keep ‘em warm and keep ‘em dry.  Bit like babies, really!

(And if you want to know more about growing these plants of creating a Tropical Foliage Garden you might like to look at my book on the subject, only $4.95 as an e-reader or PC download from Amazon, see the GardenEzi  website at www.wix.com/jrlakemedia/ezibooks )

Growing dendrobium orchids the GardenEzi way

Sep15

King orchid growing on a rock

(This article is for those who live in climates where they can grow Dendrobium orchids out of doors.  It’s not for collectors and competition growers whose plants, especially if grown in cooler climates indoors, need a much higher degree of care).

Dendrobium orchids are very independent plants and they don’t like a lot of fuss.  Gardeners who have problems growing them remind me of parents who treat their children like hothouse plants – won’t let them do this, won’t let them do that in case they come to harm.  Rearing children in this unnatural way turns them into adults who lack strength of character and the ability to fend for themselves.  It’s just the same with dendrobiums – give them the right environment and the basics of a good life and they’ll grow up big and strong and tough and resilient, able to survive all the world can throw at them. When they are in flower you think that anything so exquisitely delicate MUST need hothouse conditions – yet in the wild they grow on trees and rocks, exposed to the elements, surviving drenching rain and drought.

Cooktown orchid (Dendrobium phalaeonopsis)

Ever since I founded the GardenEzi easy gardening Five Step Program (see www.wix.com/jrlakemedia/ezibooks ) I have used the same method for writing most plant articles as I do for my books – breaking it all down into the Five Ps of gardening: Planning, Preparation, Planting, Practice and Protection.  So here goes:

PLANNING – Much depends on where you wish to grow your orchid. You may wish to imitate nature and place it on a tree or rock in your garden.  More likely, however, you will want to provide it with an artificial growing medium such as a piece of bark fastened to a hard surface, or a cork board, a pot, or a basket. Dendrobiums do best in a position where they have morning sun and light overhead shade, with protection from direct midday and afternoon sun, as well as hot winds, cold winds and (if grown on or near the ground) frost.  The Australian “king” or “rock” orchid Dendrobium speciosum will handle temperatures down to zero or even a bit below for short periods, as will the pink rock orchid (Dendrobium kingianum); the Cooktown orchid (Dendrobium phalaeonopsis) will tolerate temperatures down to 50 degrees F (10 degrees C) and so will the popular Dendrobium nobile hybrids.  Some of the Asian and Pacific species require higher temperatures and no frost but all dendrobiums cultivated in gardens require night temperatures of no less than 60 degrees F (15.5 degrees C) during their dormancy period in order to flower later.  When planning for containers, it’s the size of the maturing stems and leaves that’s important – the root system grows very slowly while you can expect at least one new step a year.  Choose a size roughly twice that of the plant and pot (or basket!) on as required.

PREPARATION – If you are growing your dendrobium in a pot or basket (the latter is better) make sure the container is filled with plenty of coarse, fibrous material.  You can buy a commercial orchid mix or make your own with coconut fiber or peat moss.  If using a pot make sure it is shallow, wide at the base and has at least THREE good-sized drainage holes; put small rocks or pebbles or bits of broken-up terracotta pot in the bottom, to ensure perfect drainage.  You can’t pot these orchids using an ordinary potting mix and expect them to do well – they are epiphytes that must develop an extensive mat of roots to survive and grow.  They can do this on a wall or rough wooden fence, provided you place them on a slab of bark or cork to start with; in a pot or basket the roots will need plenty of room to spread.  I prefer a cane or wooden basket, placed where the roots can grow outside the container on to some other surface when they are long enough, or be easily trimmed back if necessary. Pack the bottom of the basket with sphagnum or peat moss (I once used an old coir doormat, chopped into pieces, with great success!), then add some coarse orchid mix.  I usually put in a few twigs and leaf mold from the garden to hold this in place and provide plenty of “open work”; a few small rocks are good too, or a handful of coarse gravel.  The idea is to give the roots protection and some initial nutrition while allowing free drainage.

PLANTING – (Or placing!).  If you are going to grow your orchid on a tree or rock, tie it firmly in place with any binding material that will rot away as the orchid roots spread and find their own anchorage.  NOT plastic, or wire!  If you’ve bought it already fastened to a piece of bark or similar, you need only to bind this to the growing place.  If it’s in a pot you’ll need to remove it carefully so that the roots aren’t damaged and then bind it in place.  The same goes for a division from somebody else’s plant – in both these cases pack sphagnum or peat moss, or soft bark, or burlap (hessian) around the root system and tie the whole lot in place.  If you are growing in a pot or basket take the same care in handling the roots and see they are securely in place with the growing medium packed loosely but thoroughly around them.  Use the same careful root-handling procedure when potting on, once the plant becomes too large for its container – where necessary cut the roots with a sharp, clean knife.  Mature plants can also be divided in this way, increasing your collection.

PRACTICE – In warm-temperate, sub-tropical and tropical climates the dendrobiums readily available to gardeners don’t need to be moved under cover in winter.  They all experience a cold-season dormancy period when they produce no new shoots and at this time they require very little water.  I usually give mine a sprinkle or spray with a fine mister once a week if the weather is very dry, or if I notice any sign of dessication in leaves or stems.  In areas with winter rainfall, overhead protection will prevent the plants becoming too wet for prolonged periods. In summer, when new shoots appear, watering should be regular and plentiful except when it’s raining.  Though feeding is not strictly necessary, if you want more and better flowers then apply a half-strength monthly dose of liquid fertilizer.  I use a standard balanced mixture in summer to encourage leaf and stem development, switching in autumn to one which is higher in phosphorus and lower in nitrogen, to encourage flower development.  This rewards me with superb spring blossoms.  Other growers have different methods but there is general agreement on regular light summer and autumn feeding, and no fertilizer at all in the cool season of dormancy.  No pruning is necessary but it’s a good idea to remove any withered leaves or canes as these are not only unsightly but may indicate a fungal disease which can spread to the whole plant.

PROTECTION – I never give my dendrobiums any protection at all against insects.  Nor have I ever had any problem with fungal diseases. As these orchids grow outside, rather than in a bush or greenhouse, Mother Nature seems to take care of pests.  However, like all plants they CAN be susceptible to attacks from insects such as aphids, thrips, scale and two-spotted (red spider) mite. All these can be dealt with by washing down with ordinary dishwashing detergent, though repeated infestations might need a chemical treatment as recommended by your nursery retailer.  Rusts can be a problem, showing as reddish-brown marks on the leaves and stems. These tend to occur in long periods of continuously wet weather.  You can buy a treatment from your nursery retailer. Other fungal diseases are usually too advanced by the time you notice the effects and it’s mostly a waste of time trying to treat a plant that starts to blacken and rot.  The best regime is to make sure your orchids are well-drained, have plenty of air around them, won’t suffer from sunburn (which will scorch the leaves and leave them shriveled and susceptible to fungal attack), and are not exposed to frost, hail or wind.

There is a lot more I could say about growing dendrobiums – especially about propagation and the many different species and varieties available today.  But this is enough to get you started – if you want to know more, contact me on my GardenEzi website, or via this blog, and I’ll answer any questions.