skip to main content

Worm Farming

Worm farming is another alternative to composting; it is also referred to as 'vermiculture' or vermi-composting. Want to give it a go? Here are some tips to help!

What is Worm Farming?

Worm farming is another alternative to composting; it is also referred to as 'vermiculture' or vermi-composting.

Worms happily eat food scraps and excrete valuable materials known as vermicasts and worm tea which are high in nitrogen, phosphorous and potassium (NPK) compared to ordinary soil.

The benefits of Worm Farming

  • Casts and worm tea are fantastic for plants
  • If you have mostly kitchen waste and live in a home with little or no outdoor space, a worm farm is a good option
  • Same environmental and cost benefits as composting
  • Kids enjoy them.

How to get started

Mitre10 has a guide to starting a worm farm as well as links to buy any products you may need-

If you’d like something a bit different then Forest and Bird have a guide on making a worm farm out of old tyres-

Types of worm bins

Bins generally have two to three layers; some bins can have extra layers added to increase capacity. Note that it is easier to harvest worm casts from bins which have more shallow layers. Size, price and functionality vary a lot, so ask questions before you buy!

What worms like

  • Moist fruit and vegetable scraps
  • Coffee grounds and tea bags
  • Aged horse manure
  • Dirty paper
  • Crushed eggshells
  • Vacuum cleaner dust
  • Hair

What worms do not like

  • Spicy food, chilli, onion, garlic
  • Meat and milk products
  • Flour products
  • Large amounts of cooked food
  • Garden waste
  • Shiny paper
  • Citrus/very acidic fruit

Common worm farming problems




Rotting food

Too much for population

Feed less

Fruit/vinegar flies around farm or small white bugs and worms

Too acidic

Cover food with damp paper and add Lime to increase pH

Worms climbing up sides/worms very fat and pale

Too wet

Add paper products and dry leaves, gently fork holes in the working layer


Too dry or acidic

Add water/lime. If your worm farm is on legs, place each leg in a container of water to stop such pests from getting in.

Food rotting and not eaten

Too much food/wrong food/ pieces too big

Add less food, break into small pieces

No worm tea

Not enough water

Add water

Frequently asked questions about Worm Farming

  • How many worms do I need to start?

1000 is OK, but a bin takes some time to get going; 2000 worms (500gms) will get a bin working much more quickly and efficiently.

  • What if there are lots of fruit flies?

Add a decent sprinkling of lime and wait a day or two. If you still have flies, add more lime and carbon material (e.g., paper or dried leaves).

  • Do I need to lime my worm bin?

A small handful of lime or gypsum once a month helps to keep the food sweet.

  • What do I do if I go on holiday?

Add to the bin as follows: 1-2 weeks: empty out your fridge of any fruit and vegetables 2-3 weeks: dried grass or coconut fibre from a garden centre or worm grower 4+ weeks: coconut fibre block from garden centre or worm grower.

  • How much do I dilute the 'worm tea'?

Worm tea is very high in nitrogen and needs to be watered down to about 1:10, or so it is the colour of weak tea. The liquid is so rich that it can be harmful if not diluted.

  • What can I do with the worm casts?

Worm casts can be mixed with potting mix, seed raising mix and compost (about 20% casts to 80% mix), and is the perfect medium into which to plant seedlings, plants and trees. Casts do not have to be diluted for use in the garden, but make sure they are mixed in to the soil. For best results, add compost and mulch as soil cover


Central Hawke's Bay District Council - Copyright © 2024 Central Hawke's Bay District Council

Disclaimers and Copyright
While every endeavour has been taken by the Central Hawke's Bay District Council to ensure that the information on this website is accurate and up to date, Central Hawke's Bay District Council shall not be liable for any loss suffered through the use, directly or indirectly, of information on this website. Information contained has been assembled in good faith. Some of the information available in this site is from the New Zealand Public domain and supplied by relevant government agencies. Central Hawke's Bay District Council cannot accept any liability for its accuracy or content. Portions of the information and material on this site, including data, pages, documents, online graphics and images are protected by copyright, unless specifically notified to the contrary. Externally sourced information or material is copyright to the respective provider.

© Central Hawke's Bay District Council - / +64 6 857 8060 /