Growing fruit trees from seeds is an adventurous and fulfilling experience. However, it requires knowledge, skills and hard work. Not all seeds successfully grow into trees. Seed germination succeeds only when there is a correct amount of light, temperature, moisture and aeration. Extra care should be given so that the plants can go through one of the critical stages of their life.
Choose seeds of plants that are adapted to tropical climates.
It is difficult for fruits like apples and strawberries to survive in the lowlands of Malaysia as they need cold weather to grow and fruit normally. You can start with common plants such as papaya and citrus. Or, you can try growing some exclusive, local candidates such as starfruit, cempedak and mangosteen.
Before sowing the seeds, prepare a shady, sheltered environment. Get a seed tray or seed bed ready.
The depth of the seed tray is preferably about 10 to 12 cm (minimum 6 cm; maximum 15 cm). Make sure the seed bed is free from weeds and has good drainage.
Mix up a germination medium for the plants.
A good germination medium is well-aerated, moist, loose and yet firm enough to support the young seedlings. Generally, use course, washed sand (to encourage aeration and drainage) and organic matter (for moisture, soil texture and nutrients). Common materials such as weathered sawdust, coconut fibre, loamy forest top-soil and compost can also be used. Avoid adding weed seeds or pests into the germination medium. Remove stones and gravels if there are any.
Put the germination medium into the seed tray. Pat it down gently so that the surface is smooth and even. The thickness of germination medium is 1-2 cm, depending on size of the seeds. Smaller seeds need thinner medium. Leave enough space above the medium in seed trays to cover the seeds and permit watering. If seed bed is used, add 5-10 cm of germination medium on top of it. Gently rake the medium to level it.
For smaller seeds, scatter them evenly over the surface of germination medium. For seeds that are large enough to pick up, sow the seeds individually and space them out at 2-3 times their diameter.
Cover the seeds with more germination medium or a mixture of coarse sand and fine gravel (2-4mm diameter).
Do not cover seeds with fine soil particles or lumps of earth as the former impedes drainage while the later restricts emergence of young shoots. The thickness of covering depends on seed size:
Seeds less than 2 mm diameter: just enough to cover them;
Seeds 2–5 mm across: cover with about 4 mm;
Seeds larger than 5 mm: use about the same depth as the seed diameter.
There are some seeds that require light to germinate. In such cases, the covering should be thin enough to allow light penetration.
If the germination medium is moist enough and the seeds contain enough water for germination, do not water the seeds immediately. Sprinkle the seeds with fine droplets if watering is needed.
Cover the seed tray with transparent plastic sheet to slow down drying. However, check the seeds regularly and remove the sheet as soon as the shoots emerge.
Signs of good germination
The seeds germinate well if the seedlings pop up. Emerging seedlings often have their shoots bent over like a hook. The shoots then straighten out in the light.
Seed leaves either remain below ground or emerge and turn green. The first foliage leaves of seedlings usually look different from the leaves produced later. Therefore, be careful not to remove them when weeding.