Seed Biology 101

The topic of seeds can get pretty complicated. Inside one tiny seed is a whole host of genetic information that determines what and how your plant will grow. Basic seed biology is pretty much made up of three things; the seed embryo (the baby plant), the endosperm (your plants’ initial energy source) and the seed coat (protects your baby plant until it is ready to grow).
To grow your seed into a mature adult plant, you need to germinate it. This means you will be converting it from its dormant state to a state where it is actively growing. To germinate your seed correctly, there are a couple of things you need to consider.

Firstly, you need to think about the external conditions your plant needs. Things you might like to consider include water, temperature and oxygen supply.

When you first bring home your seed, it will naturally be quite dry. Watering allows moisture to accumulate inside the seed. This is then able to break down the outershell and convert the endosperm into a useable nutrient.

Once you have thoroughly watered your plant, you should think about temperature. Temperature is an important part of seed germination because of the effect it has on the metabolism within the seed’s embryo. If you store your seed at a temperature range that is either too high or too low, you are unlikely to see germination happen. For most seeds, this range is between 15 and 26 degrees celsius, but some seeds will tolerate temperatures as low as 4 degrees! Google your seed’s germination temperatures if you are unsure.

If you don’t think you can achieve your desired germination temperature naturally, you can use supplemental heating in the form of a heat mat or fluorescent lighting.

Another factor that is required for proper seed germination is oxygen. Oxygen is present in your grow medium’s pore spaces and it is important because it helps your plant develop its root system.

When you plant your seed too deep within your medium, it can become waterlogged and your seed may no longer be able to germinate. This isn’t as much of an issue with some hydroponic grow mediums like expanded clay or coco/perlite mix, as these mediums promote aeration and improve the supply of oxygen to your plants naturally.

How to plant your seed in hydroponics:
Now that you have considered all the external factors needed to ensure your seedling is set up for success, it’s time to plant! Here is our step by step guide for planting your seed into hydroponics using a mixture of coco coir and perlite.
First, lightly moisten your coco/perlite mixture. This makes sure moisture is evenly distributed throughout the media, without risking over-saturation.

Next, you’ll need to create divots in your coco/perlite mix that will home your seeds. Space each divot about an inch apart in a grid-like fashion. Most seeds will need a depth of about one-quarter inch but refer to the depth listed on your seed packet as this will be more accurate to your specific seed.

Place one or two seeds in each of the divots you have created, and cover them over with more of your coco/perlite mixture. You don’t need to pack this down too much, as you want to make sure your seeds have access to oxygen.

Finally, spray the entire tray with a handheld water mister. If you have pre-moistened your medium, it should stay wet long enough for your seeds to germinate but check-in and re-spray if you notice an uneven distribution of moisture.

To increase the chances of germination, an optional step is to plant your seeds in a starting tray with a lid as this will maintain a higher level of humidity.

Your seeds don’t need a light source pre-germination so feel free to store them in a cupboard until you see seedlings pop up from the medium, at which point you will need to make sure they have access to a source of light for photosynthesis.

We hope this newsletter has cleared up all your germination woes, happy planting!