How to Grow from Seed

Growing from seed is a rewarding experience that is easy and inexpensive to do. 
It is also a wonderful learning opportunity for children, allowing them to watch a tiny seed germinate and grow into a thriving plant. Sowing seeds in seed trays indoors is a great way to get a head start on the season and also an ideal way to grow varieties you only need a few plants of such as tomatoes, capsicum, cucumber and melon. Once the soil has warmed up enough, you can sow seeds such as carrots, lettuce, spinach, radish, salad greens, beans, peas and spring onions straight into the garden.

Seed Sowing and Germination

The most important factor in successful seed germination in trays is to always use fresh, good quality seed mix such as  Daltons Premium Seed Mix. The seed mix provides all the nutrients growing seedlings need. 

It is best to use fresh seeds as some varieties last longer than others. Check the ‘use before’ date on any seed packets.

The process of germination in gardening basically means the sprouting of seed after a period of dormancy. Different seeds take varying lengths of time and conditions to germinate successfully, and it’s important to plant them at the correct time of year. Some seeds or seedlings won’t survive a frost, and others will need a cold period to germinate, so plan ahead and check the seed packet to see if seeds need to be sown directly into the garden or indoors before being transplanted. 

Sowing indoors

  1. To sow seeds indoors firstly fill the tray ¾ full with Daltons Premium Seed Mix. Make sure the soil is damp but not too wet. As a rule of thumb plant the seed twice the depth of the size of the seed, so for example, a 1cm size seed should be planted 2cm deep. If you are planting tiny seeds such as lettuce or broccoli, just sprinkle the seeds in a line and cover lightly with Daltons Seed Mix.
  2. If you are planting a bigger seed such as a bean or pea, run your finger across the soil in a line to make a shallow trench. Place the seed mix in the trench, plant the seeds about 5cm apart and top with Daltons Premium Seed Mix.
  3. Seed lines or rows should be about 5cm apart to allow for growth prior to transplanting. Make sure you label each row so you know what you are growing and date it too. 
  4. Once the tray is full, pat down the soil and give it a very gentle watering, with a mist spray. Seeds only need warmth and water to grow. Initially, you can put some glad wrap over the top to keep the warmth in, and then place them in a nice sunny spot such as a window sill. As soon as the seedlings start to emerge remove the plastic covering. Be careful not to overwater your seeds or let them dry out. A good mist spray every day will create the perfect environment. 
  5. All the food the seed requires is contained in the actual seed and will keep it going until it forms its true leaves, which are the leaves that follow the first two leaves that every seed produces. These true leaves do not look like the others and once they have emerged you can start thinning out the seedlings. 
  6. Pricking or thinning out is to remove any surplus seedlings that have grown, to stop overcrowding and give them air and room to grow. Start thinning out as soon as they are big enough to handle; use your thumb and forefinger to pull them out or nip them off at ground level to avoid disturbing the roots of surrounding seedlings. Keep the healthiest-looking seedlings.


Professional Tip: Sowing your seeds at home is rewarding, plus it saves you money. Make your own origami seed pots using recycled newspaper or re-use egg cartons. For the best germination results always use fresh mix and seeds. Daltons recommends Kings Seeds

Planting Seedlings

  1. Seedlings grown indoors need to be “hardened off” before being transplanted outdoors into the garden. It’s an important step and can result in wilting or death from the sudden change of conditions if not done correctly. To acclimatise seedlings put trays or pots outside in the sun for an hour a day in a warm sheltered spot, extending by an hour every day over 10-14 days. Always bring them inside each day, especially at night. 
  2. On transplanting day, make sure you have prepared the soil by mixing in plenty of Daltons Compost. To prepare the planting site use a hand trowel to move the soil apart. Remove the seedling from the tray by holding the leaves and use a pencil to gently push under and up to release the roots. Carefully put the seedling in the hole with as least root disturbance as possible. The young seedling should sit flush with the ground level. Pat and firm the soil around the stem then gently water.


It’s important to water consistently for even germination and growth, but avoid overwatering as this can rot the seeds and cause damping off. This is when seedling death is caused by fungal diseases, including some root rots. 


Once vegetable seedlings have become established and commenced active growth, you can feed them with a side dressing of Garden Time Vegetable Fertiliser every 3-4 weeks (depending on variety).

For flowering plant seedlings, you can feed them with Daltons Premium Rose & Flower Fertiliser every 3-4 weeks.


Slugs and snails love juicy young seedlings. Once you have planted them in the garden, protect them with non-toxic pet and child-friendly slug/snail pellets. There are also organic alternatives you can try, for example, beer traps, and surrounding plants with Daltons Propagation Sand (No.2), bark or sawdust.



Gardening Terms Explained

Germination The sprouting of seed after a period of dormancy.
True leaves Seedlings sprout with two sets of leaves that almost look like clover. After a few days, a third single leaf will emerge that looks different – this is the first true leaf.  
Hardening off The process of slowly exposing new seedlings to outdoor temperatures before planting them in the garden.
Damping off This is a term used when seedling death is caused by fungal diseases, including some root rots.