Composting

 

Over 27% of everything that currently goes into the average Port Phillip resident's rubbish bin is organic waste from the kitchen, vase and garden. That's almost 70 kilograms per resident each year. Organic waste in landfill is a major contributor to greenhouse gas emissions. In 2006, methane generated from this source accounted for 79.2% of the total emissions of the Victorian waste sector.

Composting food scraps and peelings, spent flowers and garden clippings not only diverts a major waste stream from landfill but converts it in to fertiliser and mulch for your pots and garden. Even the smallest apartment with no balcony can compost all kitchen waste hygienically and without smells because there are some great composting alternatives just for this purpose. What's more, they are pretty affordable.

 

What is compost?

Composting is a process where kitchen and garden waste breaks down into re-usable organic matter. This decomposition happens with the use of naturally occurring bacteria that help to turn kitchen and garden waste into re-usable plant food and soil conditioners. They also help to keep harmful bacteria and smells at bay. With a little maintenance and care, it is easy to have a hygienic compost system that doesn't smell.

 

What is mulch?

Mulch is also a soil and plant conditioner but largely because it allows moisture retention and protects beneficial elements in the soil. Mulch is also a great way to keep weeds under control; they are less likely to grow through it or seed in it. Mulch is great for use in most parts of the garden. In vegetable beds however, use suitable mulches such as hay combined with fine shredded brown material or mushroom compost. There are many sources of mulch: tree, bark and green waste (tree litter, twigs, leaves, shredded branches), hay, lawn clippings, stones and pebbles, shredded newspaper and cardboard, even old carpet! Mulch purchased from nurseries and retailers can be made with a variety of green waste such as shredded cuttings, branches, bark or crop by-products (coconut husks or sugarcane refuse). Larger homes may find a home mulching machine or shredder very useful for making all larger garden waste into mulch. While plant-based mulch decomposes using a similar process to compost, its breakdown is much, much slower. Always ensure a mulch cover of 8-10cm in beds and borders. 

 

What can I compost?

You can compost almost everything that you might throw out into your rubbish bin, except plastic, Styrofoam and other items that are not biodegradable. The only limitation is the type of composting system you use. Some are designed to cope mainly with kitchen waste. Almost everything you add will decompose faster if chopped up a little or shredded.

• Spent flowers and bouquets from the vase are great in the compost. Just roughly chop up stalky or woody bits so they decompose quickly.
• Shredded newspapers make a fine addition to compost bins, but add in moderation to worm farms and do not add to bokashi bins.
• Vacuum dust and hair are absolutely fine in the compost, including pet hair and nail clippings. They don't decompose easily and have almost no nutrient value but do balance the mix by adding dry grit and fibre.
• Fireplace and barbeque ash are terrific sources of potash for plants and can be added in moderation (5-10%) to the compost. Don't add them to worm farms or bokashi bins; instead, mix some into the compost when it's ready to use.
• Kitchen waste. Almost everything that is used in the kitchen can be composted. Some types of food and peelings, however, need to be added in moderation.
• Fruit and vegetable peelings, skins and scraps; spoiled vegetables, bread, pastries, pasta, rice or salad; coffee, tea and sink dregs; and cooked leftovers are all fine and compost easily. 
• Eggshells are a wonderful addition; just ensure you crush them before adding, as they decompose slowly.
• Seafood peelings, shells and waste are excellent additions to any compost. Just ensure they don't make up more than 15% of your compost to reduce smells and unwanted visitors. Also note that shells and bones will not break down easily.
• Meat, dairy products and high-fat foods such as cheese or deep fried leftovers decompose more slowly, can smell a little and attract pests. To minimise problems, ensure these foods do not make up more than 10-15% of your compost mix. 
• Garden waste. Almost everything from the garden can be composted. Garden waste mixed with kitchen waste produces more balanced compost for your plants. Bokashi bins and even worm farms are too small for all garden waste, so try a compost bin or bag instead.
• Grass clippings are a wonderful addition to your compost bin or worm farm. They break down quickly and add nitrogen to the compost mix. Dry clippings in the sun for a day and feather them out to prevent clumping before adding them to the compost.
• Green material, including fresh leaves, twigs, thinned seedlings and vegetable patch trash, makes a great addition to aerate and balance the nutrient content of your compost. Just break larger twigs and stalks up a little to fasten the process.
• Brown material, including dried garden waste such as dry grass clippings, brown twigs, stalks and leaves, shredded dry branches and clippings, adds balance and much needed aeration to compost bins and heaps. Shredded newspaper and hay can also be used as brown material.
• Weeds are fine in the compost, particularly those that haven't flowered and don't yet have seeds. Most weed seeds can be killed during the composting process as big piles and bins can reach quite high temperature levels. Just to be safe, however, don't compost weeds with persistent root systems, or weeds that are going to seed. Instead, contain their spread by popping them in a black plastic bag, secure it and leave it to dry in a hot sunny spot away from moisture for 2 -3 months. This should kill the weeds, and the residue can be popped under a tree.
• Thorny plants such as roses are fine in the compost but can be dangerous when you are applying the compost to plants! By all means throw in thornless parts of spent flowers, leaves and roots but keep spiny prunings separate and either shred with a shredder and apply with thick rubberised gloves to seldom-used spots in the garden or bundle up neatly for the next green waste kerbside collection.
• Pet waste. Dog and cat poo can be composted successfully in bins, piles and tumblers, even worm farms specifically reserved for this function! It is best, however, to compost them separately, particularly if you intend to use your compost on your veggie patch. To make an effective and safe pet composter, dig a little pothole about 45cm deep by about 15-20cm wide near an established tree or shrub, then fit a piece of piping about the same diameter and about 60-75cm long into it, so it protrudes above, and cover it with an upside-down plastic pot as a lid. Pop pet waste into it and mix it with grass clippings and, occasionally, eggshells and tea/coffee dregs. Occasionally add pet poo compost accelerators (available from your pet store). Move your system to a new spot once it is almost full. You can also buy a shop-made version of this system.

 

 

 

What can't I compost?

Some kitchen waste does not belong in the compost:

• Oil does not decompose easily and can be detrimental to the health of some plants. Excess waste oil from cooking should ideally be poured into an old milk carton half filled with sand, and when full, taped up and placed in the rubbish bin.
• Milk and cream in small quantities are fine (such as in leftover foods) but don't empty leftover cream and milk into your compost on a regular basis. It will decompose but is likely to smell and may attract pests.