Pioneering Hydroponics

Since 1976


The complete guide to growing hydroponically from seed

Don’t be threatened by growing from seed. It’s simpler than you might think.

Sure, it might take a little longer and involve a little bit more effort, but there’s a certain satisfaction that comes from being able to see a plant grow from it’s most humble of beginnings, right through to huge, high-yielding plants.

First steps to growing from seed

1. First things first, you’ll need something to put your seeds into. We recommend a small coir pellet, like a Jiffy 7, or an inert rockwool cube, like those from Grodan

2. You’ll then need to soak your cubes in clean water for around an hour

3. When they’ve soaked put a few seeds into the media. Try a few in each just in case a few don’t germinate

4. Place your cubes into a grow tray or propagator, like our X-Stream Heat (Details on how to use that below) and add water to the tray

5. You should then see your seeds begin to sprout in about 4 days

First steps to growing from seed

How to grow from seed using a propagator

1. Place the propagator in an area with lots of light. If you can’t find such an area, use a T5 light like Sunblaster lamps or Street Light LED's. Seedlings prefer lower light for early growth, so place propagator in a semi shaded position. If using artificial light take advice from your lighting supplier

2. If the outside temperature is very low and a high soil temperature is selected you may need to cover the propagator to reduce heat loss.  To maintain a consistent temperature, a heated propagator, like X-Stream Heat, could be a massive help

3. When seedlings have germinated open the vents gradually to decrease humidity. Once the humidity has dropped (when there are no water droplets on the lid anymore) open the lid to gradually increase ventilation, eventually remove the lid. If you have the ability, adjust the temperature setting, usually 2–3ºC lower 

4. Make sure to avoid crowding of plants as this can lead to oxygen and light starvation. You will achieve better results if you leave just the healthier seedlings

5. When leaves appear the plants are large enough to be handled and should be transplanted into pots trays or a hydroponic system. Stems are very fragile at this stage; make sure to handle them with care

6. For accurate temperature control attach a thermostatic control to your propagator

7. To encourage your seedlings to grow stronger, you might want to consider adding a half-strength nutrient

How to grow from seed using a propagator


Before moving anything on, make sure there are plenty of health roots at the bottom of your plant pot or grow cube. You’ll see signs of this in around 2 weeks.

If moving to a hydroponic system, make sure to create a space and add additional media.
So, if you’re in a grow cube, place the smaller cube into a larger one.

When the seedling has been transplanted into your hydro system, you might want to top feed for a few days. This will give them a chance to develop enough roots that can obtain feed from your hydro system.

There you have it. It really is that simple to grow from seeds.
So, next time you’re starting your grow, make sure to try growing from seed.