Vegetables like lettuce, pechay, tomato and pakchoi have small seeds. Directly planting the seeds can cause lower survival rate of your plant and to avoid this, pregermination is a must.
To pregerminate your small seeds you will need the following: seeds, sterilised media, shallow container, and water.
When buying any seeds in the market, make sure to check the percent germination and sowing date to ensure high germinability of the seed. Choose seeds with higher percent germination and earlier sowing date or testing date (should be 6mos. to 1yr prior to your planting date).
For the sterilised media, you can either choose choir dust, garden soil or sand. It is important that your media is sterilised to remove potential harmful living things (e.g. insects, weeds, bacteria, fungi) that might destroy your seeds. You can sterilised the media by cooking it in a pan or steaming it for around 30mins to 1hr and then let it cool before use.
It is necessary to have a short/shallow container. Here, I used the coffee lid and sample cups from SB.
You can now fill-in your containers with media. I also tried the coffee grounds (from Starbucks) as media but you will see later on if the seeds survived using it.
Before putting your seeds make sure to label your containers. With this, you can track the age of your plant and if you choose to pregerminate more than 1 variety you will not be confused (since some small seeded vegetable seeds may look similar at young seedling stage).
Get your seeds now and start putting it on the media. Spread the seeds evenly and thinly for easier transplanting.
Water your seeds/seedlings occasionally. Avoid overwatering or drying the media. The first step in seed germination is imbibition wherein water goes inside the seeds to soften the hard and dry tissues inside. Water uptake will cause the seeds to swell up splitting the seed coat and allowing water to enter faster and the embryo to go out of the seed. Water also activates biochemistry of the embryo.
Put it in a safe place or under dark or light conditions if it is a photodormant seed (seeds requiring light or dark conditions to germinate).
Expect the appearance of your seedlings 1-2 weeks from sowing. These seedlings are ready for transplanting.
Note: As you can see, seedlings were not observed on the coffee ground media – probably because the texture was so compact that the embryo had a hard time going out of the seed or due to high acidity of coffee inhibiting the germination process of pakchoi seeds.