Onion Weed

I help out a friend, doing her garden half a day per week. At this time of year, (spring) too much time is spent getting rid of Onion Weed (Nothoscordum inodorum) which has spread over large areas of the garden. It spreads by both seed and tiny bulbils which form on the main bulb in their hundreds.  (see photo)

Depending on the situation, there are a few ways the job can be done and I am using a combination of the following.

POISON

First, remove any flower heads as they will remain viable even after poisoning.

Onion Weed bulbils

Glyphosate is quite effective, especially mixed with a little ammonium nitrate or ammonium sulphate at normal foliar fertiliser rates. The leaves suck up these nutrients along with the glyphosate. If it is not already in your glyphosate product, you can also add a few drops per litre of detergent, to overcome the repellence of the waxy leaf coating. If there is any danger of overspray getting onto plants you want to keep, then you can use a broad paintbrush or if the infestation is thick enough, a paint roller on an extension to save your back.

Glyphosate will not kill off the bulbils unless they have sprouted above the soil, so poisoning may take a few seasons.

If you touch one of your valued plants by accident, remove the affected leaves straight away.

Onion Weed flowers and seed heads

PULLING OUT

This can be the quickest method, but requires a great deal of care not to spread the bulbils which detach themselves from the main bulb on the way out. I use a garden fork to loosen the ground under the bulb and slowly ease it out as you wiggle the fork up and down to further loosen the soil. Any bulbils left behind are usually nearer the surface and will be easy to remove when they sprout, either in this or the next season.

STARVING

In a lawn, regular mowing will eventually deplete the bulb of the food it needs to survive. In a garden bed where mowing might not be appropriate, I have found a sharp Dutch hoe (also known as a scuffle hoe) to be effective in removing the tops below ground level. The lower you cut them, the more reserves they have to use to grow back and the quicker they die.

If there are too many plant roots to use the hoe, you can use a thin bladed knife or simply pinch the tops off by hand and check at least weekly for new growth.

If the situation allows, black plastic laid over the top will prevent the bulbs from being re-invigorated by sunlight. In my experience weed mat is not effective for this purpose, nor is any translucent plastic.

Above all, be vigilant.

Jon

These systems require energy to run pumps and supply fish food, however this is offset by the energy which would otherwise be expended to get fish and vegies to the supermarket and then to your table. Commercial fish food can also be supplemented with home-grown worms, which have been fed with scraps of food and other plant materials that originate from your garden.

Aquaponics systems are water and nutrient efficient and if used correctly, will pay back the energy cost of setting them up. Like photovoltaic systems this may take some time, so if you purchase a commercial product, make sure the main components are going to last.

You can also reduce the setting up carbon footprint (and dollar) cost by using recycled materials. A web search will turn up some excellent articles on this topic.

Watch this post for news on the latest in aquaponics design.

The client is having a pool installed in a small backyard.

The pool will have a cover which they wanted hidden behind a 60cm high water feature.  The pool fence is to be glass and one end has to butt up to a low,  protruding  retaining wall which provides a 30cm step.  The fence must be 1.2m above any such step.  The backyard is a truncated triangle and the client wanted a 30 cm high retained garden bed, alongside the pool to fill out part of it. They also wished to screen the boundary fence with “Natureed” on the patio side of the pool fence and replace their existing pavers.

The Solution

The pool cover was a bit of a problem as it would be difficult to manhandle over the water feature. It would also have to be sufficiently far behind it to make this manoevere practicable and therefore would be impossible to hide completely.  A design concept was drawn up by us which incorporated the water feature in a pool cover box constructed with an undershot access. It was submitted to a local pool accessory fabricator who was happy to make it. The concept resulted in better concealment, easier application, more available space and the water feature closer to the poolside.

The pool fence also presented a challenge, owing to the presence of the retaining wall. The answer was to extend the garden bed through the fence and build a feature wall at the point where they met, thereby eliminating the step. A metal art feature was suggested as decoration. The fence could therefore be kept to a less imposing 1.2m instead of 1.5m and the garden bed extension would fill in the other triangle. Plants are great for taking out odd shapes. The other benefit of the feature wall is that it provides a natural ending point for the Natureed screen.

The new paving design reflects the pool surrounds and leads the eye outside the pool fence, giving the impression of a more open space.

Plants were chosen to look great against the prevailing colour scheme, for their waterwiseness and for their appropriateness for a poolside location.

Pool Area Design

FUNCTIONALITY
All good design begins with function. Retaining walls are generally required to maximise usable space in restricted areas, however they can also be a positive feature to enhance the beauty of a garden. A well designed wall can give a garden shape, direction, colour and focus as well as providing an interesting backdrop for your plants and for other garden features.

MATERIALS
Retaining walls may be constructed from blocks, bricks, concrete, wood or stone and either rendered or faced, or left as is. Construction materials are often dictated by the style and form of the wall. The finish is best considered in the context of the whole garden, including plants, rather than a liking for a particular material. A dry natural stone wall for instance may be right for a country property, but look out of place or be overbearing in a suburban backyard.

STYLE and FORM
As a general rule, I design the wall to complement the nearby surrounds. If the wall is around the house, then the house will be the governing factor. If it is away from the house, on or near the boundary or around a pool, then the “borrowed landscape” (what is seen behind it) will assume greater importance.
The sheer scale of the wall in relation to the size of the property must be considered too. A single tall wall can give a feeling of being closed in, so it might be broken up into 2 or three terraces, if space allows, with plantings to soften the edges and create a fantastic display against the wall finish.

Terraced Wall

Jon Tayler Landscape and Garden Design: Rain Garden (plants not shown)

The Brief

This is just part of the original brief, which also included a Flora Survey. In this part, a Nutrient and Drainage plan was required for a building addition proposal in an environmentally sensitive area. The increase in stormwater run off meant that the existing sump was not large enough, however the area into which it could expand was limited. The client also wished to improve the visual aspect of that facility so that residents could enjoy that part of the grounds. The main offender was  some very ugly and prominent concrete pipework in the existing sump.

The Solution

The answer was to create a Rain Garden in place of the existing sump. Rain Gardens are used in areas where the soil is heavy, to accelerate water removal and eliminate contaminants at the same time.

Removal of contaminants which come from roofs and driveways etc is achieved through the planting of appropriate species to take up nutrients and by creating conditions which  stimulate biological (bacterial and fungal) activity to break down oils  etc.

Water removal happens through evaporation, transpiration through plant leaves and by infiltration into the aquifer. All three of these vectors are maximised by keeping water moving through the whole area. This is achieved here, by using a recycle system designed by Jon Tayler Landscape Designs.  The proposed stormwater collection and recycle system eliminates the old exposed pipework and satisfies the client brief in the best possible way – it is functional and looks great!

The residence is a solar passive architect designed house. One of the clients is an artist and would like a studio separate from the house, but in keeping with its architecture. The clients enjoy bird life and wish to extend existing native plantings around a new entertaining area, plus water feature, at the rear of the house. Further native plantings are wanted around the front of the house. They want only a moderate amount of lawn kept as a small recreation area. The soil is alkaline, which restricts the plant selection.

The Solution

The first consideration was the studio, as its placement is governed by solar passive requirements and must be open to the winter sun. It was designed in similar style to the house, in matching brick and tiles, over “Hebel Block” inner walls and a “Solar Span” (foam sandwich) ceiling. The rear wall is placed in line with the front of the house, to enable a feature gateway to span the two buildings.

The new entertainment area is to be paved and will extend beneath the two existing louvred patios which are not weather-proof and a new domed patio which will span the 4.8m gap between them and extend further toward the fence. The super six fence will be screened with brushwood and the water feature colours will provide a pleasing contrast with its charcoal grey. There is an Olive tree near it which has sentimental value and will be paved around.

The plants chosen will ensure flowers for most of the year to encourage bird life and most have interesting foliage, providing a display all year round. They have been placed to maintain an open aspect. As an added bonus, they will only require watering for establishment or extreme conditions and a waterwise drip system will be used for this purpose.

Water girl