Compost – bins and tips

Compost Bins

Compost can be made in a variety of containers. The examples below show a double bin made from recycled timber, a double bin made from recycled, heavy gauge bird wire covered with knitted polypropylene shadecloth, and a commercial single bin. Double or triple bins are best as you can turn the compost from one bin into the next, with the third bin used to start a new heap.
dblcompost compostbins2

Homemade containers don’t require skilled carpentry. What goes into the compost container is more important than how it looks.

 

SAMSUNG DIGIMAX A503 SAMSUNG DIGIMAX A503 Compost tumblers (on right) do the work of aerating the mixture. They are suitable for composting small quantities of fairly soft ingredients quickly, for people who are not able to turn compost easily, but the mixture may not generate enough heat to kill diseases. The main points to remember in deciding on the size and site of your compost container are:

  • When ingredients form one cubic metre (i.e. 1 m. x 1 m. x 1 m.), aerobic bacteria will generate enough heat to kill diseases and weed seeds.
  • Open-base bins that are in contact with soil allow earthworms to enter the mixture (when it has cooled down) and provide worm castings to the mixture while they help complete the composting process.
  • Recommendations to position compost bins in full sun do not apply to many parts of Australia, as too much heat can kill off composting organisms. A shaded spot is ideal.
  • Compost bins need a cover to prevent the ingredients becoming sodden in heavy rain.

Some Composting Tips

If you are new to compost making, don’t be intimidated by statements of the ratio of carbon to nitrogen in compost making. Most recommended ingredients contain a mixture of both. With a little practice, you will quickly learn to identify and correct any imbalances.

  • Chop up tough items using shears, a shredder, or a sharp spade (spread items on soil or grass first to prevent jolting). This assists faster decomposition as bacteria work on the surfaces of organic waste. The more surfaces you can provide – the faster they can work.
  • The secret to making compost quickly to turn it regularly to keep it aerated, and to keep it damp as aerobic bacteria that commence the process require nitrogen, air and moisture to process the carbon.
  • The secret to fast composting is regular turning and mixing of the ingredients. Weekly turning while the ingredients are generating heat will produce mature compost very quickly. As the compost breaks down, the mass is reduced.
  • You don’t have to wait until you have a cubic metre of ingredients – turning and mixing ingredients will get the bacteria working.
  • If the pile looks grey or contains ants – it is too dry. Turn and mix the ingredients, while adding enough water to dampen the mixture.
  • Don’t be concerned about slaters in your compost heap. They feed on semi-decomposed organic matter.
  • If the pile is black with an unpleasant smell – it is over-wet. Air has been forced out, and anaerobic composting has begun. Turn and mix the ingredients, while dusting with agricultural lime every 15 cm, and adding some straw to the mix. Protect pile from rain.
  • If the pile seems inactive – it may need more nitrogen. Turn and mix the ingredients, while adding some manure every 20 cm. If manures are unavailable, you can substitute a generous sprinkling of poultry-based, organic-allowed fertiliser.
  • Your compost is ready when it is dark brown, crumbly, with a pleasant earthy smell and ingredients, apart from pieces of egg shell, are no longer recognisable. A 5 cm layer added to topsoil provides your garden with all the minerals that plants, animals and humans need for good health.

Passionfruit – hand pollination

To ensure that your passionfruit vine produces lots of delicious, juicy fruit, you may have to hand-pollinate the flowers. Passionfruit vines rely on bees for pollination because their flowers have a large gap between the 5 oval, pollen-bearing male parts (anthers) and the 3 V shaped, female parts (stigmas). There are generally less bees around recently, and they don’t like to venture out in wet or windy weather.
The oval anthers release their pollen early in the morning, but the best time to pollinate is mid morning when the stigmas at the top of each flower bend downwards and secrete a sticky fluid that helps the pollen to adhere to them. The photo below shows the ideal position of the stigmas for pollination.

Only when the female parts of each flower receive passionfruit pollen can the flower form a fruit.
If there aren’t many bees around your passionfruit vine, or if you have a young vine with few flowers, you can pollinate the flowers by hand. The best way to do it is with a soft watercolour paintbrush, and this short video demonstrates the practice beautifully: Hand-pollination of passionfruit
Another way to hand-pollinate is to remove an anther and brush it onto the stigmas. However, each flower needs at least a hundred ovules to develop into seeds for healthy fruit. Otherwise, the fruit will be hollow, or lightweight and not juicy, so the paintbrush ensures a good dusting of pollen where it is needed. Dust the pollen gently over the underside of all 3 stigmas of a different flower on the vine, then repeat with the next flower.**
Passionfruit take 2 – 3 months to develop and ripen – the very popular ‘Nellie Kelly’ slightly longer. Passionfruit, like good wine and cheese, taste best when they are mature. Fruit should have a deep colour and feel heavy. They are juiciest when they are slightly wrinkled.
** Some hybrids and cultivars need a second variety for good cropping. Check with your nursery before purchasing a vine.