This or ?

This was never going to be a land speed record. We do the work around here and most is done manually. We also have competing interests - a day out on Moreton Bay vs digging holes in the back yard ... indeed it is amazing anything gets done.

 

CHALLENGE No 1: Sloping Site with Limited Vertical Drainage

1.0 The 1960's solution: Direct surface water into a concrete race

In the 1960s the block at the rear of the house was levelled by building a flyash concrete retaining wall 1.5m in from the rear and side boundaries. A maze of earthenware pipes was laid, the area filled with ash then topped with soil which introduced nut grass. The 1.5m wide U shaped sloping perimeter was concreted up to the boundary.

A neighbour told us the reason for this was to deal with the run off. Deal it did. Surface water coming down from the front and the neighbours place ran across the concrete race, hit the wall, then continued on down gathering speed before hurtling down through the downhill neighbouring properties. Over the years the concrete race had been ruptured by trees and this is was how it was when we bought the place.

1.1.1 The Millennium Solution: Level the entire back yard

Eventually we built a low core filled, steel reinforced concrete block retaining wall backed by socked agi pipe, copious drainage gravel topped by tonnes of busted concrete. Ash and several inches of dirt (with the gift of more nut grass) levelled the entire backyard. The 1.5m perimeter at the rear of the backyard has eventually become a path again, this time finished with compacted roadbase topped with a layer of decomposed granite (deco).

This design allows the water to pool, seep through the deco and continue via the weep holes, or, during very heavy rain, disperse over a large area before overflowing the pavers that top the retainer wall.

1.1.2 The Millennium Solution: Build raised garden beds

Each time I picked up the mattock it revealed a hither to unknown pipe that usually resulted in a colossal archaeological dig. There is something to be said about having plans, but plans are not always available for the likes of earthenware storm water pipes, foundations of bird cages and grease traps. The concrete and rubble added to the stockpile of dirt and clay we had already removed when paving under the deck. Once we had our dump volume sorted, it gave us an idea as to what height to build a sarcophagus which would form the basis for a raised garden bed.

Most of the beds are contained by steel reinforced core filled concrete block walls. The inside of the beds are sealed with a bituminous paint and lined with corflute. The outer wall was smooth rendered followed by a tyrolean finish which was either painted or finished with an oxide. These walls are capped with pavers which came from a neighbour's driveway. The NE corner garden is made from sleepers which are stained a dark green.

1.1.2.1 The deck garden

As you walk down the brick steps on the western side of the house a level L-shaped level garden bed rises up on your left as the land falls away. This L-shaped garden is viewed from the deck. It was the first garden bed we built. With multiple constraints on it's height, it needed stepped footings to accommodate the three way slope. The agi pipe from the driveway grate continues through this bed which also has dripper irrigation and feature lighting (Channel 2). It is a large bed. It might be a bit too wide as I cannot reach the middle. However, I did not want something that would be vulnerable to drying out and unable to support some small feature trees.

This bed took a massive amount to fill. Fifteen years of compost followed by six (6) cubic metres of 'premium' organic soil (painful mistake - it had a pH of 8 to 9). More compost, bags of cow poo, mulch and do it all again. After two (2) years the level has finally stopped dropping. The end result is a well drained highly friable black soil loaded with earthworms.

1.1.2.2 The fern garden

• Square shaped raised bed on south side of dividing wall
• Finished with tyrolean spatter using mortar pigmented with black oxide and capped with pavers
• Removable black weld mesh panel above bed
• Tap on wall in NW corner
• Next to seating area with patchwork brick floor laid in black mortar
• Ornate panels allow breezes, keep the area private while providing glimpses of garden beyond
• Garden bed receives morning and (unfortunately) late afternoon sun
• Feature lighting (Channel 2)
• Dripper irrigation
• Long term plan is for overhead shade to reduce radiant heat on northern aspect of house

1.1.2.3 The citrus bed

• Rectangular raised bed on northern aspect of dividing wall
• Wall finished with tyrolean spatter using mortar pigmented with tuscan oxide and capped with solid bricks
• All day sun
• Weldmesh panel painted orange attached to central column
• Stainless steel wire suspended by eye bolts running from one end of wall to the other above the black panels
• Columns pre-wired for lighting
• Dripper irrigation
• Northern aspect of bed created using treated sleepers

1.1.2.4 The main pergola

• Dominant feature in backyard although presence not immediately apparent
• Position set by back stairs and laundry
• Acts as pathway, seating area, provides shade from western sun, reduces radiant heat and cools air rising up hill
• Upper aspect is viewed from deck, kitchen and office windows
• Western concrete block columns link structure to deck garden
• Eastern galvanised columns are set back into NE garden and have plastic mesh for training vines to counterbalance the visual effect of the block columns
• Northern aspect finished with tuscan oxide
• LED lighting strips on the underside of the purlin ribs - the overall effect is a soft glowing curve (lighting Channels 3 and 4)
• Deco path with two multicoloured clay brick scoop drains
• Walking north, turn left at the edge of the deck garden onto a brick patchwork landing, a step up to a deco path running under shade pergola
• A little further north, offset to the right is a deco path to the kitchen garden with the citrus bed
• Back under the pergola further north is another deco path on your left - a direct (wheelbarrow friendly) route to the utility area
• At the northern end is an improvised bird bath off to right
• Turn right at the end, straight ahead in the NE corner is the Hills Hoist with deco up to the boundary

1.1.2.5 The rear shade garden

• Created to offset the visual dominance of 10 000L tank in NW corner and provide planting for privacy along the northern boundary
• Long term this area is likely to cater for chickens - a dwarf mulberry and shade pergola are already in place

1.1.2.6 The native garden

• The loss of the poinciana in the NW corner left this area exposed to all day sun
• The garden bed introduces a rising curve (similar to the shape of the purlin ribs) into an otherwise rectangular design
• The curved wall is capped with sandstock bricks
• The curve rises up to a height which ties in with the corner columns and rear garden bed wall
• Corner columns are capped with solid bricks and feature a metal post insert - for umbrellas or act as a sleeve for another post (eg for a trellis)
• Variable soil in this bed, overall there is more clay, but there are two areas of river sand
• The bed has been topped with copious (around four (4) m³) mulch from poinciana
• Persistent Nandina domestica, clerodendrum and nut grass require intermittent poisoning

1.1.2.7 The western boundary gardens

1.1.2.7.1 Front yard

• Start in the SW corner of the carport with a waist high hedge (our neighbour likes this height and keeps it neatly trimmed)
• The transition to a taller hedge occurs at edge of the carport where you step down from the concrete slab to a brick platform
• To your left is a weldmesh panel which runs overhead and attaches to the frame of a three part silver gate
• At the front edge of the brick platform a low concrete block wall widens the garden and allows for soil to be built up
• The colours in the rear garden hardscape are introduced with the use of black oxide in the mortar of the brick platform (laid in a non-directional offset basket weave) and in the tyrolean spatter finish of the garden bed
• The garden bed widens at the top of the stairs where it is punctuated by a flat column
• The flat column is for a feature pot which is off set by a dividing wall at the foot of the stairs
• The feature pot acts to move the line of sight away from the central panel of the gate towards the top of the stairs
• A second brick platform and a handrail (re-purposed from the original back stairs) also cues the brick capped stairs
• Washed blue stone pea gravel is the finished surface for this secondary pathway as it facilitates drainage, is a neutral colour, provides audible security and allows for another transition back to brick patchwork at the top of the stairs
• The pea gravel conceals a diversity of infrastructure including two (2) 100mm rainwater collection pipes, 240V (running to NW corner of block), subsurface drains and pre-existing mains gas line (the meter used to be on western wall of the house)
• The gate is illuminated from the northern aspect by a concealed LED strip light (Channel 1), the garden has three LED bollard lights (Channel 1) while the stairs are lit by an LED mounted under the paver cap (also Channel 1)
• A vertical dividing wall between the western boundary garden and the deck garden lines up with the last step and creates a tension point by narrowing the line of sight and concealing a part of the garden beyond
• On each side of the vertical wall is a stainless steel wire threaded into a diamond pattern with a perimeter for training a vine

1.1.2.7.2 Back yard

• Moving to the backyard, there is another small western boundary garden bed just north of the space in the fence and pit drain
• This small bed is made from sleepers, lined with corflute and filled with compost
• The area gets at least three hours of direct sun until it is shaded from the afternoon western sun by the fence
• Attached to the dark green secondary fence (concealing blue line pipes from NW tank) are several stainless steel wires, two of which run alongside an old bevelled mirror in a painted timber frame
• The idea of this bed is to train a composite of vines that have a perfume and white flowers as north of this bed are the compost bins
• In front of the bed is a brick patchwork completed with grey mortar

1.1.2.8 The eastern boundary garden

• Limited to the front yard, the main role of this emergent garden is to provide privacy, then as you move away from the boundary, an aesthetic area to view from both the bedrooms and while sitting outside
• Preferred colour scheme is a cool one (green/grey/purple) to offset the warm colours in the bricks and terracotta

1.1.2.9 The front gardens

With a wide frontage on a downhill sloping verge, a tall solid fence can become the dominant feature. Such fences can appear imposing and unfriendly, it can also obstruct breezes, and in our view, increase security risk by keeping the house hidden. We also had an angled front boundary to integrate into the design. Another requirement for the garden area was that it needed to cater for a box trailer and kayaks. While the trailer needed to be off the street, the kayaks are better secured out of direct sunlight.

With this in mind a pergola with a shade cloth roof was incorporated into the design of the front fence. The trailer is parked on a bed of pea gravel while the kayaks are slung from the purlin frame. In the end the wide frontage was taken up by (from west to east) a concrete platform, double driveway, pedestrian walkway, a high wall (to direct people to the pedestrian entrance), a low wall with columns linked by weld mesh cages, the pergola entrance then another concrete platform.

The area behind the front garden has a free standing raised garden holding three large builders tubs. These are for our neighbours children. The surrounding raised beds are filled with compost enriched topsoil. The area receives morning and late afternoon sun. The aim is the cover the weldmesh cages with vines in a way that may encourage smaller birds.

The area where the carport is now sited used to have terracotta clay pavers.There was no overhead shade. In summer, the pavers became so hot that you could not stand on them in bare feet. With this in mind we decided to only pave the SE corner, an area where the ground was shaded by the house and the grass never grew. While it may have looked better to have continued the pavers all the way across to the raised garden bed, we deferred doing this because of our concerns about radiant heat and ensuring surface water drained away from the house. We did not know whether an overhead vine would create enough shade to render the area useable in high summer. It was also unclear whether we might be better off turning this area into a casual lawn or flower meadow. Given these uncertainties and the finality of paving (at considerable expense), we decided to mulch the area and wait and see.

1.3 The Millennium Solution: Permeable paths where possible

While decomposed granite (deco) allows downward movement of water, if there is a slight slope and heavy rain, shearing forces readily gouge a channel in the deco. Two scoop drains set into path under the main pergola have not been that successful in re-directing the water onto the lawn during heavy deluges and find ourselves having having to shovel the deco back to where it was washed out. Maybe some strategically planted prostate ground covers, grasses or lomandra cultivars could help slow the water and hold back the deco.

We addressed the recurring problem with overflow from the small tank washing away the deco by moving the tank and directing the overflow through a pea gravel bed before it ran over the deco. We have since observed that pea gravel can be washed aside when the tank overflows, but it is a lot better than it used to be. It is an issue which could benefit from further thought and likely be addressed when considering how to shade the rear of the house.

The front yard is covered with tea tree mulch. It allows the water to percolate while we sit back and think about what we might plant. Tea tree mulch is also used in front of the compost bins where it provides a ready source of carbon.

1.4 The Millennium Solution: Restore permeable surfaces

A sloping concrete driveway used to accelerate surface run off during heavy deluges. The crossover and driveway had been disrupted by incursion of roots from the poinciana on the verge. The driveway was removed. The council supervised the digging of the footing for the front fence and arranged for a root barrier to be placed at the property boundary across the trailer pergola.

Part way down the slope a low wall with weep holes was built at right angles across where the driveway used to be. This has a small return which disappears into the slope. The wall is backed with 100mm socked agi pipe covered with drainage gravel topped with geotextile fabric. The area behind the wall has been built up with compost to create a planting space.

1.5 The Millennium Solution: Re-direct or hold surface run off

We do not want surface water pooling around the house as moisture can attract termites. On the western side of the house a bluestone pea gravel path conceals a rubble drain. This, together with a pit, and, in severe downpours, the brick steps, are designed to get surface water away from the house quickly. Any water over the steps is taken away by a grate drain in front of the lower garden bed. This runs into another 100mm socked agi pipe passing under the path and into the next garden bed and under the lawn.

Any surface run off from the verge that does not run into the weep holes along the front fence continues to flow east. It runs into the pea gravel under the trailer pergola or, into a grate drain in front of the terracotta plant stand that marks the SE corner of the site. The grate drain flows into a pit which is connected to a 100mm socked agi pipe running under the eastern garden bed.

The surface run off from the new driveway and paving in front of the pedestrian entrance flows into a grate drain. This drain slopes towards the western garden where it is collected by 100mm socked agi pipe running under the garden, before continuing down and ending under the L-shaped garden bed. If the drain or this 100mm agi pipe cannot keep up with the surface run off, then water will start flowing in the opposite direction under the wall, into another 100mm socked agi pipe running north of the trailer pergola area and into the eastern garden bed.

I am not fussy where I get water from for the garden. On the western boundary a 1m pit drain gulps surface run off from the neighbouring property during heavy downpours. Twin 100mm agi pipes snake their way under the garden bed, the lawn, the path, eventually ending in the rubble drain in front of the rear retaining wall. Only during a sustained torrential downpour have I seen these pipes semi-submerged. Sitting on top of one pipe was a green tree frog.

 

CHALLENGE No 2: Hot humid summers, erratic rainfall, dry winters

One year I grew a magnificent crop of tamarillos (Solanum betceum) which went from seedlings to fruiting within eight months. All were dead before the year was out - killed by a particularly brutal Spring. Our impression is that Spring and Summer are getting hotter and more quickly. Since the begining of the year through to the start of Autumn in 2017 most days have been over 30C and the weather station in the garden has recorded a miserable 162mm of rain. Our local rainfall pattern is less of previous regular summer storm fronts associated with a large rainband to smaller, more intense fast moving cells which tend to be more miss than hit. Whenever it does rain we capture and hold as much water as possible.

When Brisbane City Council announced they were about to offer 600 rebates for water tanks, I could not get my order in quickly enough. The rebate covered the cost of the 3000L polytank, but as we were about to find out, plumbing and a decent pump cost more than the tank. After the state government repealed their rebate and the price of tanks dropped, we bought a 10 000L squat tank. We rolled this tank down to the NW corner. The two downpipes on western side of the house and carport are plumbed into two 100mm (sewer) pipes which run underground coming up at the base of the tank. The downpipes from the SE area of the house feed the 3000L tank.

Most of the raised beds have either a weepy hose or a dripper irrigation system buried under the mulch. A long run of such hose can be a significant drain on supply so I am trialing homemade olle using terracotta pots as a way to water individual plants (eg cucumbers) and large pots as. I also work with a combination of mulch, increasing the organic content of the soil, perlite, and ultimately, appropriate plant selection to limit the need for supplementary watering.

 

CHALLENGE No 3: Scarce Topsoil

The CSIRO Brisbane Soil Map shows we have Pullenvale (Pu) soil which has "little profile development" characterised by "lithosols with thin red-yellow podozolic soils" such as "low hills of greywackes and shales". In other words rock and clay. We are near the top of a local ridge. When we dig a hole and pour in a bucket of water, we do not count the number minutes/hours/ days it takes to drain, we count wrigglers. If we dig in the right place water will well up.

The clay has a pH of around 6. Depending upon the moisture content it can be parred with a spade or it comes out in huge clumps. It clagged the treads of our boots, dried hard and eventually stomped off as a fine dust. For this garden it was always going to be onwards and upwards with organic matter. The lawn continued to grow and we continued to eat so there was always some vegetative matter to go into the mix. Over the years I have found that it takes a phenomenal amount of organic material to generate a small volume of soil, soil we have needed by the cubic metre.

Mulch is by the trailer load. Organic Xtra, dolomite, gypsum and NatMin are bought in 20kilo bags. Cow and aged chicken manure (the later for the compost and citrus) are also by the trailer or ute load. Improving the soil is ongoing and making good compost is not always that easy.

3.1.1 Composting: The pyramid plastic compost bin (Fail)

Bought from the hardware store this promised a compact urban solution for kitchen vegetable scraps and grass clippings. When the cat hauled in yet another large rat, I was convinced there must be a plague and rang the council. When I affirmed that yes, there was a macadamia nut tree next door and, yes I had a compost bin, the person on the help line said that any rat would be an expected accessory to those facts. The bin was pulled apart to reveal a thriving rats nest.

3.1.2 Composting: The plastic tumbler (Fail)

This tumbler worked in one respect - there were no rats in it (no self respecting rodent would bother), but then again whole macadamia nuts lying around suggested the rats were not outdoors at this time of year. Maybe they had gone indoors to make a meal of the wiring in someone's house as they had done here. While puss had been a superb ratter, at 14 years he only had four teeth left. These were not small critters and unlikely to be gummed to death.

The compost tumbler was a smelly disappointment. The lid was left off to encourage it to dry out. Decent handfuls of lime and plenty of shredded paper were added. I just couldn't get it right. The tumbler was cleaned out in anticipation of warmer weather to try again, that was until I saw someone about to buy one at the hardware store. I offered them mine at a price they could not refuse.

 

3.1.3 Composting: Stacking wooden bins (revisited)

The poincianas continued to drop branches and pods and the grass clippings were piling up so it was back to a stackable wooden compost bin. The last bin was very successful until the termites made a meal of it. This time we went for three boards per stack instead of one. The final hardwood bin was two stacks high and had a volume of around 1m³. A lick of cream paint was added for durability.

3.1.4 Composting: Fixed wooden bins with removable boards (current)

The compost bins are now integrated into the hardscape along the western boundary towards the back of the section. A second timber fence was built in front of our neighbours existing slat fence. This forms the back of the four bins which are partitioned by removable timber slats (originally used as boxing timber). These slats slide into metal fence capping screwed to hardwood posts set in concrete. The garden bench can be washed off into the first bin. All of the front and internal partition boards are removable. This makes each bin easier to access from in front and facilitates turning over of compost from one bin to the next. Mulch is stored on the ground in front of the bins. Handfuls can added to the mix whenever extra carbon is needed. A builders barrow fits comfortably in this area.

 

CHALLENGE No 4: Northern aspect with limited shade

When we first moved in, the north facing backyard had several dominant trees. The two large melaleucas which were corrupting the concrete race were soon cut down. As one fell it took out the Hills Hoist post.

An elderly poinciana tree continued to hold court in the NW corner. Together with neighbouring palm fronds, a jacaranda (Jacaranda mimosifolia), macadamia (Macadamia tetraphylla) and an African tulipwood (Harpullia pendula) these suburban giants formed a shady green arbour. Towards the end the poinciana's canopy shaded more than half of our backyard. On a hot still night, two days before Christmas, one third of this tree considerately felled itself precisely where I had planned to set up the table. With over a tonne in the main bough alone I am ever grateful we did not make the headlines of The Courier Mail for having a "Killer Christmas Lunch". However I was sad some of my favourite garden furniture was squished and annoyed when the the Hills Hoist was taken out by a tree, yet again. The centre of the tree had rotted. It had to go.

One still Spring afternoon we were witness to another inglorious demise. A cracking sound followed by the graceful but surreal toppling of the neighbour's 60 foot jacaranda in a splendid plume of purple. Next up was another jacaranda, this one came our way, crushing the fence, cracking the retainer wall and taking out the Hills Hoist, yet again.

The loss of such large trees left us exposed to the north and west. It also left us wary of the damage they can cause. My preference is for vine clad pergolas. Given the slope of the site we get see the top of the pergolas from the deck and inside the house and, once in the backyard, enjoy walking or sitting under them in the shade.

Spring can be a very hot time of year, winters are mild so with the seasonal variation in azimuth, pergolas alone are not enough to provide shade year around. To date fast growing pioneers like Acacia fimbriata (Brisbane Wattle) have performed admirably. At two years they are around full height. They have been underplanted with Pittosporum angustifolium (Native Apricot or Gumbi Gumbi) as their long term replacement, although the later were planted a bit further away from the swaying clasp of Pandorea pandorana 'Sunset Gold'.

The backyard used to be a lawn with a path to a Hills hoist. I have no regrets trading time with the mower for a plate compacter. The mower will always be welcome as we still have some lawn and it's chipper chute preps all my prunings for compost.

 

CHALLENGE No 5: Predominance of large or aggressive bird species

We have never seen any small birds. Not even a Willy Wagtail. Large or aggressive bird species predominate including the recent arrival of Indian mynas.

The Regulars:
Crows, noisy miners, rainbow lorikeets, paleheaded rosellas, magpies. pied and grey butcher birds; crested pigeons; ring necked doves, kookaburras, Indian minors, fig birds; currawong, pied ibis (fly bys)

Seasonal or Infrequent:
King parrots (for the sunflowers or Acacia fimbriata); galahs (Acacia fimbriata); sulphur crested cockatoos (green Macadamia tetraphylla nuts); needletail swifts; channelbill cuckoos; koel; pee wees, morepork, scrub turkey.

We keep a bird bath topped up with rainwater. This is frequented by the crows, currawong, butcherbirds, pigeons, noisy miners and Indian mynas. The front fence has two weldmesh panels mounted between the columns like a hollow gabion. A selection of vines (including Jasmimum simplifolium, chainfruit vine (Alyxia ruscifolia), maidenhair vine (Muehlenbeckia complexa)) are being trained over this. The weldmesh will keep out larger birds and with time may offer a refuge for smaller birds.

 

CHALLENGE No 6: Cats and Rats

6.1 Cats

I used to have a lot of large skinks in the garden which I became very fond of. It was not uncommon for one to be snatched by a kookaburra in the midst of a duel. I suspect the overall numbers have been in decline for a several years now as I am seeing less of them and have been finding live snails in the garden for the first time. I suspect the ever increasing number of local cats and dogs have created a deadly barrage of hunting and harassment. I will be looking to integrating a network of basking rocks with nearby escape routes throughout the garden.

6.2 Rats

I don't think a macadamia tree in a suburban backyard is a good idea as they can attract rats. Rats used to carry nuts up to the house, work their way up the internal cavity and winter over in the roof space. While in residence they stripped the insulation around the mains cable. We were fortunate not to have had a house fire. In the garden they chewed a hole in the side of the plastic worm farm and ate the tiger worms. The farm was re-seeded with tiger worms from the general compost pile then wrapped with bird mesh. I now have a metal tumbler and the squirming (soldier-fly larvae) stinking mess is transferred to the compost bin once the handle gets too hard to turn.

One year we had a magnificent guest - a 10 foot python. The python never came back after inadvertently hitching a lift to Toowoomba. Apparently it caused a bit of a stir when the 4WD went in for service. My old cat and Mr Python are greatly missed. Once the chewed macadamia nuts start to appear, baits go into the drains and a bad smell starts to permeate the air.

 

CHALLENGE No 7: Aim to minimise potential for damage associated with mature trees, shrubs or vines

The plan is to be here for the long term and we do not want any self inflected hassles. When I listen to people rave about gardening in the subtropics, I sometimes wonder if I am on a different planet. Sure things grow - sometimes too well. A lot of plants fail too.

This is the first year for the Queensland Chapter of the Garden Design Study Group www.anpsa.org.au/design under the auspices national body of Australian Native Plants Society (Australia) www.anpsa.org.au It is a treasure to find like minded people whose shared experience and knowledge will help guide my choices.

 

CHALLENGE No 8: Lack of familiarity with Australian native plants

I have a profound attraction to glossy green leaves. I would have planted Murraya paniculata hedges had it not been for their strong perfume. Instead my father and I used a crowbar to plant some lillypilly cultivars Resilience and Elegance. These are proving to be a poor choice. While neither hedge has been affected by psyllid, they have been subject to repeated attack by a small smooth bright lime green beetle that looks like a stretched lady bird. The beetles strip both hedges every year, leaving them looking like a narrow leafed serrated lillypilly. Beautiful glossy green hedges rendered mangy and thin.

Thrice the hedges have been halved in height, foregoing years of growth. Chilly and garlic spray did nothing but smell. While a systemic worked, I prefer not to use it. I had hoped that the development of the garden would attract more birds, including some which would make a meal of these beetles. To date the same birds visit and the same beetles continue to destroy the hedges.

As a result the eastern hedge is being slowly usurped by Podocarpus elatus. The western hedge is under review and this is where I will be turning to other members of the Queensland Chapter of the Garden Design Study Group.

 

CHALLENGE No 9: Constraints associated with living in suburbia

This project has opened the door into a tangle of regulation and bureaucracy that makes 'Utopia' even funnier. We had to pay to have a small leopard tree removed while the cause of the issues, the poinciana remains standing. The base of the poinciana is hollow and the council tree service warned us that if the canopy is allowed to become too broad (it used to touch the ground) it risks splitting the forked trunk in two. The roots have disrupted the concrete cross over twice, a concrete driveway, a double brick fence and pushed a brick planter away from the wall of the house which collapsed an earthenware pipe. The reach of the roots for a relatively innocuous looking tree has been quite something. There is no debating which tree is responsible - there are no other trees around. While it casts welcome shade and is simply stunning in flower, a poinciana it is not the right choice for the verge as water will continue to run downhill and it will continue to come looking for what it needs.