By Thomas Brown
Your first consideration is plant genetics, make sure you buy the correct type of seed and from a reputable source. If the seeds have not been stored correctly, in a cool, dark and dry place, then they are probably only good for the bin!
Next is your choice of media, for soil growers you can use Jiffy peat pellets, rockwool or Root Riot fleximix. We would recommend Root Riot fleximix as these allow for better oxygen and water retention but also allow good drainage. For hydroponics Grodan Rockwool or Root Riot is preferred as both are an inert medium.
It is recommended to “sterilize” the seeds by soaking them in warm water, approx 50°C for about 25 minutes. You can then either plant the seeds into the chosen media or pre germinate the seeds by placing them in moist paper towels between two plates and leave them in the dark. Check every day or so to see if the root has appeared, then proceed to plant root side down into the media approx 5mm down below the surface.
Once in the rooting cube of choice, lightly water with a weak nutrient solution like Formulex or Vitalink Plant Start. If you are using Root Riot cubes or Jiffy Pellets then you shouldn’t need anything except plain water. Drain any excess water out of the rooting cube to enable the roots to breathe better.
Then you can place the seedling cube in a propagator to maintain a humid environment, around 80% humidity is recommended. Also maintain a temperature of approx 20-25° celsius, it is imperative you keep in this temperature range in root and leaf areas. Also refrain from using cold water to re wet your cubes or to mist the propagator, check periodically to make sure the cubes do not go dry. Moisture and warmth are your seedlings best friend!
Once the first shoot or Plumule emerges your seedling needs a light source to prevent stretching. We would recommend a Maxibright CFL, or Maxibright T5 light, both options need to be in the blue spectrum for healthy leaf formation. The first seedling leaves or cotyledons will grow before the first “True Leaves” are formed. One rule to follow is the more leaves a plant has the more light it needs to grow. Be careful not to have a too intense light source like a HID or HPS at this stage so the plant leaves do not dry out too fast.
Once the plant is at the first true leaf stage, remove the propagation lid at regular intervals to acclimatise the plant to a less humid environment and to prevent potential fungal diseases.
For any detailed advice on this subject please call 01733 331115 to speak to one of the Grow Superstore team in our Peterborough Hydroponics store.