Planting and Growing Seedlings

How to grow high quality seedlings using the Biointensive Method

1 Use an organic seed raising mix, (Daltons organic seed raising or potting mix is the best one in NZ) or a home made one. Most other seed raising mixes   contain fungicide which will kill all the beneficial microorganisms. These micro organisms are vital for healthy, high Brix* plants.

2 Use a seedling tray that is a minimum of 6-7 cm deep. Shallow trays do not provide enough depth to grow the best roots. We use wooden seed trays which we make from macrocarpa. We have two depths of tray, the standard ones are about 7cm deep (above the base) and we have deeper ones of about 10cm (abovethe base) for larger plants such as pumpkins, tomatoes and beans. Once the seed raising mix is in the trays , but before you plant your seed, you could choose to add a Seedling Innoculant, shown to be the most effective possible way of strengthening your plant roots and creating the highest potential for nutrient dense plants.

3 Check seed packets or Koanga Garden Guide to ensure you plant the seeds at the optimum time for their germination.

4 Plant seeds of a similar size in a tray together, so you can easily cover them with the correct amount of seed raising mix. Cover with the same soil depth as the seeds are deep. Too much soil will prevent seeds from germinating.

5 Small seeds are usually either scatter sown into a seed tray or sown in a line or drill and then pricked out later (see below).


6 Larger seeds such as corn or pumpkins are sown into trays correctly spaced. These seeds will not be pricked out but will grow on in the tray until they reach planting out size.

7 Label seeds carefully. Use waterproof pen on strips of plastic or wooden sticks.

8 Keep your seeds evenly moist but not too wet. Tiny seeds are particularly sensitive to too much moisture as they germinate. Use a watering can or sprinkler head that allows water to fall like soft rain.

9 Once the seeds begin germinating they must have full light conditions or they will grow leggy very fast.


 10 Once your seedlings have germinated, with their first two leaves above ground, they must be pricked out into another tray at the optimal diagonal spacing for that seedling. (see Koanga seed packets for details). Use the same soil mix as for seed.

11 Handle the seedlings very carefully by their leaf tips only when transplanting. We use a ‘widger’ to lift them out of the seed tray to transplant them. Plant the seedlings so that the leaves are just above the surface of the soil, bury them up to their shoulders, so that the stem is covered.

In this short video Isaih demonstrates how to use the widger to prick the seedlings out


12 All seedlings will need to be protected from wind and rain until they are almost ready to plant into the garden. Check the seed packets for details on when to plant into your garden and at what spacings.

13 Continue to water your seedlings in the way that most resembles gentle falling rain.

14 You can use a foliar feed to encourage healthy growth and raise the Brix* levels of your plants. EF:Active Calcium, or EF: Growth Foliar spray,  or something you have made yourself with vermicast or seaweed etc. You can use a  refractometer to test what is working. ( More information here about the refractometer).


15 Hardening off your seedlings before transplanting into the garden is very important. Place your tray of seedlings on an outside but sheltered bench where the birds or chickens can’t scratch them out, for 3 days prior to transplanting to avoid transplanting shock.

16 Storing your seeds: Seeds are alive, and need to be stored with care to ensure their viability. It is important to store your seeds in a dry cool environment, away from sunlight and moisture.

This information is also available in a brochure format as a pdf for for downloading here.