Before you start

Follow these guidelines to make sure your experience is safe and your seedlings are disease and pest free.

Follow good hygiene principles

  • Wash your hands after handling potting mix.
  • Be sure potting mix is damp to prevent inhaling dust.
  • Work in a ventilated area (though not in the wind as seeds may blow away).
  • Do not to put anything in your mouth whilst working with the potting mix.
  • If you have respiratory problems, wear a dust mask (available at hardware stores, chemist).
  • Store your seeds away from children.

Keep your environment disease and pest free

  • Wash your hands thoroughly with soap and hot water before you start.
  • Only use indigenous potting mix. Do not use garden soil or compost.
  • Grow your seedlings off the ground in a concrete or paved area or a raised bench.
  • Mix the fertilizer and potting mix in a clean wheelbarrow or on a clean bench-top.
  • Wash the bench-tops, trowels and other tools with disinfectant (household bleach 20 ml per litre) or tea-tree oil.
  • Do not let ordinary garden soil come into contact with your potting mix as this may introduce contaminates.
  • Wash your hands in between handling different batches of seed.
  • Carefully dispose of any seed pre-treatment water.

Prevent infection from air-borne pathogens

All potting mix can carry bacteria or pathogens such as Legionnaires which is active when airborne. To prevent infection keep the mixture damp to keep dust down and handle it in a ventilated area (dust masks can be worn).

Handle chemicals safely

Seedlings may come under attack from insects, mildews or fungi. If you use commercial preparations or chemicals:

  • follow the manufacturer’s directions
  • keep them safe from children and pets
  • remember to carefully dispose of any empty containers.

Be careful around fertiliser and pesticides

Even though slow-release fertiliser is low in toxicity, wash your hands after use and keep it away from children or pets.

Some seed banks use pesticides to protect their seeds in storage. Wash your hands, use a mask (available at chemists, hardware or supermarkets), wear gloves and keep seeds away from children and pets. Remember to always wash hands after and between handling different batches of seed to avoid cross-contamination and thoughtfully dispose of pre-treatment water.

Be careful when lifting

Full boxes weigh approximately 12 kilograms so when you lift any boxes keep your back straight and knees bent.

Keep your work space stable

Ensure your bench is sturdy enough to support the 80-kilogram TreeProject Kit. It is best for the bench waist height for easy handling of boxes and seedlings.

Tips and Tricks


  • Do keep the potting mix damp: it ensures germination.
  • Do mix the fertiliser evenly throughout your potting mix: as this helps prevent the seedlings varying in size. Note: you may need to use a water soluble fertilizer to even-up the growth and stimulate the slow ones.
  • Do fill your tubes just before you sow your seeds: this way the potting mix stays moist.
  • Do rotate your seedling boxes as this promotes even regular growth. Irregular growth happens if the seedlings have been getting lots of sunlight from the same direction. If some of your seedlings look smaller, rotate your boxes so they get more sun.
  • Do check individual plants for pests, grubs or slugs.
  • Do give seedlings just the right amount of sun and water. Too little sun and too much water – weakened plants. Some plants just look like they have been struggling while others are tall and straggly. Those that are stunted need more sunshine, or a warm spot against a north facing wall.
  • Do ensure seedlings are labelled correctly


  • Don’t overwater and pamper your seedlings: to survive our hash dry summers and changeable weather patterns seedlings need to be hardy with robust root systems. A large lush overwatered seedling will be too large for the roots to maintain.
  • Don’t let your potting soil dry out: this seals the surface and water won’t be able to penetrate into the mix.
  • Don’t use glass houses, poly-tubes or any type of enclosed shade house: they are far too hot and humid for our native species during the summer growing season and may encourage fungal infections and produce weak seedlings.
  • Don’t pack the potting mix too tightly: as this prevents water from passing freely through the seedling tubes.