I agree with everything Alison has said - if you can also let us know what direction it faces that'd be helpful.

If you do nothing else to improve your soil get rid of the Camphor Laurel as it'll gobble up the nutrients you're putting into your soil - have it professionally removed and the stump treated before it gets any bigger and remember that they're toxic (don't burn it or use as chip or allow it to be left on your property). You'll also have to watch that none of the seeds end up as seedlings - if they do, get to them straight away. If you're in NSW it's classified as a weed, just make sure that you have Council approval (so that you're totally covered).

When the Camphor Laurel is gone, to improve your soil if you're prepared to wait a little while, direct compost into the retaining wall's soil (I'd do this even if you decide to you renew it with fresh soil and ready made compost) - you don't need to do this in a trench but can do it in area's or if want to do this regularly insert composting tubes are a good idea - it'll bring nutrients back into your soil, encourage earthworms (the true unsung heroes of the garden - they provide microbial action, aerate the soil and help fertilize) and make good use of your fruit and veg scraps that normally go to landfill (nothing from the onion family or citrus if you want lots of lovely earthworms working hard for you). Burying your fruit/veg/garden waste (no weeds with seeds please - they love it) can be used across all your garden beds that gets you instantly into a form of vermiculture and you don't have to have bins/beds etc nor do you need to cart the castings around the yard (but you can't make worm tea which is brilliant for your plants).

When you've planted in your retaining wall garden - Natramin has a great range organic fertilizers (which you can throw all around your garden periodically not just in your retaining wall), and I can't recommend seaweed solutions such as Seasol highly enough (use this every two weeks or so - Seasol gets used everywhere often at my home for both roots and follage).

As a beginning gardener make your life easy and keep your costs down and go for quick fixes that pay off now and in the long term. Vermiculture is super easy, insanely cheap and pays off dividends with reducing your household food scraps going to landfill and giving you easy home made compost and fertilizer (i.f you've got kids, they'll love it). Also get familiar with companion planting. Depending upon sunlight non invasive herbs could be a winner there (no mint!).

I've put some links here that may help you until we find out about your location etc. I hope it helps.

http://www.veggiegardener.com/use-direct-composting-in-your-garden/https://www.youtube.com/watch?v=yjOqv0JX5Vg (don't put any sort of poo from carnivorous animals in it - chook and sheep poo also needs to be well rotted down and I'd avoid that too).

http://www.agsolutions.com.au/index.php/mineral_fertilisers/natramin_product_range/

http://www.foodwise.com.au/wp-content/uploads/2013/07/Worms-ONLINE-1.pdf

Thanks Alison and Georgi02 for your inputs. We are in Brisbane, QLD. The retaining wall faces the west and the long fence line faces the north. You are right about the width of the garden on the retaining wall - its only about a meter and you run into the rocks beneath so not much planting space as such.

I will seriously consider getting rid of the camphor laurel. Will the roots need to be dug out as well?.

I also like the idea of putting the food scraps in there will start doing that pronto.

Look forward to landscaping and plant suggestions.

Cheers,

Linda

Hi Linda,
There are a number of ways Camphor Laurels can be removed - it'll depend upon your aborist and local council. This will give you a guide but it'll really depend upon the size of the tree, and the rest of the site: https://www.daf.qld.gov.au/__data/assets/pdf_file/0003/65181/IPA-Camphor-Laurel-PP46.pdf

I wouldn't start trench or pipe composting until the Camphor Laurel is out - otherwise you're not doing to much except feeding it (don't encourage growth). If the tree removal will take several months - go for a vermiculture set up that will allow you to get your worm castings built up or go for a Bokashi bin set up for the rest of your garden http://www.bokashi.com.au/

Being in Brisbane and having hot summers - see if you can get Olla pots (they're a terracotta pot (well almost a bottle) that you bury with just the neck exposed and fill with water - if you can do this when you're planting your retainer wall out the roots of the plants will grow to the Olla pots taking the water they need - you need to do is fill them up and you can go a bit longer without watering - I'd suggest this or drip irrigation for the site. Both are particularly good for the types of plants you'll need. I believe that you should be getting sun the hottest part of the day and as long as you get 6-8 hours of sun, lucky you - you can grow almost anything.

Brisbane have a cool site - link here that gives you sun/shade/.height of plants and soil requirements - well worth a read to give you a full idea of your options (personally I'm envious that you can grow ginger easily). http://www.brisbane.qld.gov.au/sites/default/files/20141111_-_green_gardening_guide.pdf

One of the big problems that needs to be considered with dry-stone walls is that they are extremely porous. So you will probably get a lot of seepage through the rocks that is not being utilised on site. And the narrowness of the bed doesn't help.

I would have a stump remover remove the stump after removal of the camphor laurel. One of the issues with camphor laurel is that they are allelopathic - meaning that they restrict/prohibit plant life beneath their canopy.

In order to suggest plants for this bed, I really think that my best advice is to use only indigenous plants - they will be far hardier for the area than exotics. If it were my garden, i would like to see height in this spot which will be hard to achieve unless you use really hardy plants. I would be inclined to suggest Grevillea olivaceae or one of its hybrids. You can hedge this plant or just leave as is. Even when not in flower the foliage is great, reminiscent of the olive tree. The flowers are great for bringing birds to the garden. I don't feel that there is enough space to consider a ground cover over the wall because of the lack of root space. The Grevillea will take up all the space and the ground cover will never do well. And the wall looks good and doesn't need hiding.

I would also suggest a watering system to your plants - with a dripper to each. You need to consider adding extra rocks at the bottom end of the wall going around to the fence - once the tree is removed. Here I would consider cementing them into place as this will be the runoff point to the garden area as it is the lowest point. You will need drainage holes at the bottom of the wall so that the plants aren't waterlogged. Then back-fill with good quality topsoil - its worth paying for better quality. Don't use too many plants in the area if you go with the Grevillea that I have suggested if you aren't going to hedge them, as they grow to a good 2 metres wide, so they only need to be this width apart. Mulch them after planting, use a wetting agent which will stop run-off and then just nurture them and wait for them to grow.

I hope that his helps.

I love the idea of citrus trees in pots buried in the ground. A row of them provide great bushy dark green foliage, require minimal (only once a year) pruning, a great fragrance when in flower and best of all... fruit! Having them in pots and then burying the pots, means that you can limit their growth so they always remain the height you want and means that you don't have to enrich the soil that is already there nor, get rid of your existing tree. I saw a great example of this along a fence line on a recent gardening show and it looked great. You can always plant some ferns or small flowering plants in between the fruit trees.

Would bamboo grow on a retaining wall - not much depth or soil due to rocks underneath

Would planting a fruit tree in that spot be viable - considering there will still be some mulch/roots from the camphor laurel in the soil. Will it make the fruit toxic or inedible?

Would a hedge of ixora or camelia or hibiscus be viable on the retaining wall?

I like the idea or using grevillea for hedge - considering that too. Need something that would grow fast.

Thanks heaps,

Linda

Hi @yard_guard - what did you end up doing in your backyard? Would love to see an update. If you decided to go ahead with the hedge or the fruit tree, it might be established by now.

Would love to see more photos if you have time. :)

Luke

Two plants I can suggest that I have chosen for my garden, are virtually unkillable, will grow in almost ANY soil or weather conditions & require little maintenance are: butterfly/african iris & Celtic Cascade tree.

Both can be left to go a little wild for a natural look, or be cared for, to fit perfectly in a more formal garden.

In regards to the iris, I removed my entire garden of mature, property damaging trees when I moved into my new house, but didn't want to wait years for a new mature garden, so I searched online for ppl selling/giving fully grown specimens away before they did renovations or re landscaped! The plants were a cinch to dig up, replant in my heavy clay soil & are thriving! I even cut some of them in half before planting and it didn't phase them!

Did you know that the Celtic Cascade is a weeping form of the pussy willow - Salix caprea? This has a shocking root system for pipes and drains. The African iris grows easily because it is classified as a weed in some states.Seeds disperse and germinate really easily in many parts of Australia.

Hi! Have you thought about integrating Permaculture ideas to get the most out of your garden. Don't worry if you're new to it - it's fun! It is a simple, yet effective design science which makes the most of space, plants, the climate etc. A set of permaculture principles and ethics will help guide you to organise the space in order to get productive, edible gardens - for example, design something that has more than one use - it saves time and money! If you are going to put the work in, it makes sense to get something out of it!

find out about Permaculture principles + ethics here:

Finally, hv logged in again. It's been a busy year. But here is what I ended up doing with the backyard. Not perfect but considering it was our first DIY, it's Atleast better now than before

Gardening is a wonderful outdoor learning experience. You should be proud of your first attempt. I hope that you have enjoyed the experience of working with nature.

Now watch it grow.

Alison

FWIW the Camphor Laurel is on BCC weed list, bet it smelt good cutting it down though.
http://weeds.brisbane.qld.gov.au/weeds/camphor-laurel