Monday, 5 December 2016

Rejuvenating a Degraded Front Yard

The most difficult plant-establishment task in our home has been the landscaping of the front garden…

1. The Objectives

Our objectives for the front yard were simple… Firstly, this was to be an area, heavy with fragrant plants, a garden for the senses. Secondly, we wanted to attract the local butterflies into our home.

2. The History

As we have explained in earlier posts, our home was a ‘knock-down-and-rebuild’. During this process, unfortunately, our topsoil was moved and removed from what was to become the front yard. Consequently, what remained was a very thin layer of soil sitting upon a bed of clay.

Sadly, our first attempts to establish plants in this area were abject failures: we lost many of our prized plants in the first two years, including a large number of Aussie native plants. Furthermore, many more of our target species really struggled to take a foothold, looking feeble and sickly.

One of the few plants to thrive in this degraded soil... an Australian native, Grevillea sericea

3. The New Approach

Because of our inglorious beginnings, a dedicated approach would need to be taken. Where we had established our back yard with relative ease, the front with its shallow topsoil was going to be a more difficult proposition, requiring time, patience and a clear strategy. So, how did we go about rejuvenating this difficult landscaping task?

·         Spread garden soil mix. From the back-filling of a retaining wall, we had some left-over garden mix. This was spread over a large part of the front yard.

·         Apply Gypsum. A major problem for us came during periods of heavy rain: the water would run off and away in a stream from the front soil. In order to break down the impervious clay subsoil, we applied liberal doses of gypsum to the soil. Notably, gypsum is highly effective in improving soil structure and water infiltration. However, it also has nutritional benefits to plant life as a source of calcium and sulphur.

·         Remove the undesirables. Even though our desirables were regularly ‘meeting their maker’, the undesirables (weeds) were able to find a way to inhabit this hostile environment. We would need to make a determined effort to keep the soil weed-free to give our desirables a fighting chance.

·         Cover with Sugar Cane Mulch. For the past three years, we have provided a heavy covering of sugar cane mulch to suppress the weeds and to retain soil moisture. Even though there are more beneficial mulches, such as pea straw or lucerne hay, we have utilised sugar cane mulch because of its ready availability in the city.

·         Create our own Compost.
A situation like this makes your compost bin the most valuable item in your garden. We have been applying our own home-made compost to the front garden soil for the past two seasons, and it has made such a difference. The compost is rich in nutrition and wildlife, gardens worms by the score to work their magic in restoring the health of the soil.

Pelletised Chicken Manure

·         Fertilise, fertilise, fertilise. With the planting of each new specimen, we have incorporated plenty of Pelletised Chicken Manure in the planting hole. This is followed by a liberal scattering of Blood-and-Bone as the plants have started to establish themselves.

Blood and Bone
·         Understand the needs of individual plants. The fragrant garden holds plant members whose needs are antithetical to each other. For example, where our kasturi lime and pomelo trees respond to the alkalinity of gypsum, garden lime and dolomite, our gardenias and Chempaka tree detest similar conditions. We have had to keep liming agents well away from the gardenias and Chempaka (Michelia x alba) lest we invite disaster!

·         The Secret Ingredient. Last year, the front yard was heavily planted in parts with marigolds, both the tall and short varieties. Not only have we discovered that certain species of butterflies find the marigolds attractive, but also that the marigolds are a soil fumigant. At the end of the growing season, the marigolds were pulled up, chopped up and spread over the surface of the soil. We had read that, by keeping this marigold mulch moist, pest nematodes (which inhibit the ability of plants to take up nutrients and water) would be fumigated and exterminated by the gas released from the decomposing marigolds.

This year, we have allowed the marigolds to self-seed and regrow to repeat the cycle of soil fumigation and renewal.

A Painted Lady Butterfly is attracted to the golden blooms of the marigold

4.  The Front Garden Today
A major transformation in the health of the front garden has taken place. No longer are we losing our newest plantings. Furthermore, the area is visually more inviting and clearly more productive, with a greater diversity of plants surviving and thriving. An indicator of this increased health is the number of visiting birds and butterflies.

However, our efforts are not yet complete because problems remain… an ailing Chempaka tree, a young pomelo which is flowering heavily, but not yet setting fruit, and a young Chokanan mango tree of four years, which is failing to thrive. Otherwise, important strides have been taken in the rehabilitation of a degraded section of our garden.

A Spring Display of massed annuals. On finishing their season, these annuals were mulched into the soil...

Wishing you hours of enjoyment and contentment in your garden…

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