Raising plants to be grown in NFT
Using compost
Germinate seed in a seed tray of compost. When seedlings are large enough to handle, transplant to a suitably sized plastic pot with drainage holes or germinate seed in the correct sized pot.
Water as necessary. If your compost contains nutrient (check the label) use water only. If your compost doesn’t contain nutrient use a complete hydroponic nutrient at half strength. If necessary adjust pH in the watering can.
Your plants are ready to be transplanted to your NFT system when you can remove the pot and the compost remains bound by the white roots of your transplants.
Using rockwool
Before using rockwool soak overnight in water at pH 5.5 and allow to drain. This reduces the alkalinity of the rockwool.
Plant the seed in the rockwool cube. Gently bury and cover over the seed using a blunt instrument and allow to germinate.
When the seedling develops its first green leaf, begin to water sparingly with half strength complete hydroponic nutrient. If necessary adjust pH in the watering can.
When the seedling has developed white roots to the outside of the rockwool it can be transplanted to a larger rockwool block which has been soaked and allowed to drain as before.
Keep seedlings watered with half strength hydroponic nutrient. Your plants are ready to be transplanted to your NFT system when you have lots of white roots on the outside of the large block.
Using aeroponics
Young plants can then either be transplanted to an alternative medium, e.g. rockwool and grown on before transplanting to your system, or grown on in the propagator until the roots reach 3 to 4 inches in length and transplanted directly into your NFT system.
If growing from cuttings, follow the instructions for raising from seed but DO NOT use nutrients in the water until your cutting has rooted.
Tip: For raising seedlings or cuttings, over-watering slows root growth dramatically. Always keep your plants slightly on the dry side.
When to transplant into your NFT system
Do not plant into your NFT system until the plant is well rooted (almost rootbound) – your plant needs to have lots of white roots on the outside of the compost or rockwool block.
If white roots aren’t on the outside of the growing medium when you place your plant into your NFT system the roots will become saturated with no access to oxygen and will die-back.
The plants pictured below are ready to be transplanted into an NFT system. DO NOT transplant until your plants are at this stage, regardless of size.
Key points to remember
- Transplant when well rooted.
- Ensure atmospheric (air space) environment is suitable for your plants.
- Follow nutrient instructions.
- Maintain nutrient and pH levels.
- Monitor and control pests and diseases.
Common causes of poor growth
- Plants placed in the system too early – ensure that only well rooted plants are used.
- Adding to much acid when lowering pH levels.
- Incorrect nutrient dosage used – always check the manufacturer’s instructions.
