Gardening with Thought

How much do you know about your garden and the ecosystem it is part of?

Gardenia variegata Flower

If you’ve been around for a while you will know that I am somewhat vocal about growing things that suit your environment. I may even be a bit stroppy about it at times. But there is a reason, and it’s not just my bad temper coming out! Humans are incredibly hard on the environment around them, in all our modes, our current way of life is certainly harsher on the environment in high-density city or town living, but even nomadic living influences the ecosystems around us. This means we should have a focus on giving back more, as we are through our very existence, taking more away than other animals on the planet. But do we? Ignore climate change completely, I’m not even going there, what about plastic, our waterways, mass farming techniques, replacing food crops and forest vegetation with biofuel crops, pollution, mass clearing, our fear of trees in the suburbs, rubbish, fast fashion, and the non-stop noise that is humanity? At what point in this mess do we give back to our environment in a way that is meaningful, without placing our own desire for order upon it?

If we are really trying to leave less of a footprint in our world, we need to start thinking in a more holistic way. This requires gardeners to consider more than what they want the garden to look like and start to think about what is appropriate to the conditions. What are the key factors you need to think about when considering this? The very first thing you need to understand when choosing a plant is your own site, and strangely enough, this is often not really something we stop to think about. Darwin is a unique environment, with some wildly varying conditions, and some key unifying factors. The wildly varying soil structures do have one key similarity and that is a high level of porosity. 

Now before your eyes glaze over and you stop reading altogether, this is not as bad as it sounds, high porosity is ultimately the reason you don’t live in a lake during the wet season. So, along with our massive growth rates, consistent temperatures, and no truly dormant period as the upside, the downside is our soils often do not hold moisture well, and have very little organic matter. This means we need to mulch, mulch and mulch again to try to improve the organic content in the garden and its ability to hold the water you apply to it during the dry season. The material you mulch with needs to be organic in nature, so leave the gravel for your paths and drains, it is NOT suitable for garden beds in this climate. Gravel or stone will raise your soil temperature by a minimum of 5C, and drastically increase your evaporation rates, which is exactly the opposite of what you are trying to achieve with mulch. So, whip out the hay, the bark, the composted leaf mulch, and the compost and add it to your soil, and like magic, everything will suddenly get a lot easier. At least until after the next wet season when you need to do it again, hello monsoon leaching!

When trying to understand your soil structure its good to remember where you are. The Northern Suburbs of Darwin are nestled in between Mangrove, Escarpment, Monsoon Vine Thicket, and a Flood Plain (Darwin Airport). This means before people, these areas were quite rich in foliage with a huge biodiversity, and quite healthy soils, relatively speaking. But right now, they are probably sterile, full of fill, palm roots, and suffering from years of neglect. Palmerston is actually very similar, and the rural area, is a whole world of variety thanks to the sheer size of it. However, the majority of the population is working with good basic bones, it just needs to be restored.

So where to start? Well, the mulch is going to help, but so is some basic fertiliser, a bit of water, and some shade. You need to get some fungus into the soil to start the food cycle for your plants. We’re not going down this particular rabbit hole in this story, but in a nutshell, Mycorrhizal fungi are essential for plants to survive, and they do not live in sterile soil. You need to introduce good bacteria and balance the elements within the soil to ensure they can all react with each other and the plant roots. The best and easiest way to do this is with organic matter, compost, and a low dose fertiliser. This fertiliser doesn’t need to set the world on fire with its NPK rating (4:3:3ish is pretty well perfect), we are talking simple and quick here. Manure is tempting at this point, but manure aint a fertiliser, it’s what we call a ‘soil improver’, it is often lacking the same elements that are low in your soil structure, because generally those animals fed off grass and food grown on ground that was also low in those elements. So, by all means, use the poo, just use the fertiliser as well to get a good top up of major and minor elements.

Now the hard part, shade. This is a difficult thing for people to work with sometimes, and we understand why. But there are two things everyone needs to be aware of, and the first thing is a terminology problem. The terminology problem lies around the term ‘full sun’. You see, when you see the term ‘full sun’ on a professionally printed label with pretty pictures on it pushed into a pot, it means this plant either requires or will tolerate 6 hours of direct sun each day. What it does not mean is, it will thrive in 12 hours of equatorial sun at 35C each day. It actually doesn’t even mean it will tolerate 6 hours of equatorial sun at 35C every day, because these terms and plants are generally defined and tested in temperate climates. For your own curiosity go and run a quick internet search for ‘what does full sun for a plant actually mean’ and open a few links, you will see the issue we have with this term pretty quickly. The basic concept is Darwin sun just doesn’t hit the same as Adelaide, Melbourne or Sydney sun, not even Brisbane sun, especially during the dry season. So your exposed new build in Zuccoli, Muirhead or Stuart Park, is not ‘full sun’, it is more like 2 days worth of sun each day, in sterile soil, with very little water retention, and your recently cleared block in Noonamah is probably 3 days worth.

The other thing we need to remember is babies don’t live in the sun. Nearly every living thing in the world at least attempts to ensure their offspring’s survival by hiding them in sheltered positions. Gecko’s and Snakes, which are known to abandon eggs after laying them, still lay them under leaves, or in nooks and crannies where they are out of sight. And they are generally born with the ability to survive. Plants establish in areas where they have water and shelter, seeds generally fall from a tree where there is shade and will germinate when the conditions are appropriate, and most plants adapt to flower and seed during key seasons to ensure germination. Weeds in pavement grow where there is dew and use the mineral content of the gravel and other materials to gain their nutrients. Plants have evolved methods to thrive in certain conditions, but as juveniles, almost universally they prefer some shelter. And key here is another terminology issue, we are talking about babies not liking sun, not light, bright light is generally very important, but it is not the same as direct sun. Indirect bright light is fabulous for seed germination and seedling development, and for pretty much all propagation whatever the technique, direct sun however can be a death sentence. Just like you don’t want to leave your newborn baby out in the Darwin sun all day, you shouldn’t expect juvenile plants to tolerate it either.

So even with our amazing growth rate (one of the fastest plant growing sites in the world), all the good intentions in the world are not going to get you the results you want, if you don’t think about your site, and plant with thought and consideration. What is appropriate for your site and situation? It isn’t always a native, or an exotic, and sometimes the ideal garden for you and your family, isn’t the one you thought you would have. But that is the fun of gardening, it is challenging, always changing, and best of all, its good for you, as long as you are not afraid to try something new.