Growing on - 31/01/08

The cucumbers are now needing to be watered with nutrient solution (EC 1.5) every 2 days. The roots are doing really well and can be seen on the top of the block. Without the block covers the roots would not be growing on the block surface. These plants should be ready for their NFT system in about 1 week.




The cabbage are also coming along nicely, they are getting watered from the top (canna coco nutrient - EC1.2) until some run-off leaves the bottom of the pot every 4 days.



The tomatoes are also doing well and the flood and drain table is working a treat. As the nutrient solution get recycled I check the pH and EC every 2 days to keep it the pH between 5.8-6.2 and EC around 18. Tomatoes like higher nutrient strengths in comparison to cucumbers and chillies and I will increase the nutrient strength up to EC of 22 before transplanting onto their final systems.

The chillies and peppers are slower growing but are coming along without any problems. These are still getting watered every 3-4 days. You can generally tell when plants need to be watered by lifting the block. If it feels heavy then leave it alone, each day you will fell it getting lighter until it needs another watering. Knowing when they need a watering comes with practice, the important thing to remember is not to water without checking if the plant needs it.

Transplanting part 4 - 28-01-08

10 days after transplanting the tomatoes and cucumbers the chillies and peppers start to show their roots through the small roockwool cubes and so are moved into the larger 4" rockwool cubes.



To make some space for all the new seedlings I have moved the tomato plants onto a 1m squared flood and drain table. I have made a mesh tray to fit inside the table for the blocks to sit on. This mesh allows the blocks to air-prune while the flood and drain system waters the plants evenly from the bottom.

The nutrient solution is stored in a 80L reservoir and is pumped up through an inlet onto the table where the water level rises to 2cm above the mesh tray where it overflows back into the reservoir beneath. This means the bottom 1/4 of the blocks get wet while capillary action draws the solution through the rest of the block. To ensure even watering you have to make sure the table is level, the legs have adjustable screw feet to make these adjustments.

I timed the first flood (without plants in) to program the digital timer, it takes 4 minutes to reach the desired flood height which is maintained for 1 minute to allow the blocks to suck up some solution. This means the pump should be on for 5 mins. The tomato plants up to now have had nutrient solution through the top of the block every 3-4 days and now have the first signs of roots through the bottom of the block. Now I can put them on the flood and drain table and program the digital timer to come on every 3 days to flood the table at 12:00. As the plants get bigger this will increase to every 1-2 days. In the past I have watered by hand but when you've got over 100 plants to do every day it can take up allot of time. These tomato plants should be ready to planting out in 7 to 10 days.

Transplanting part 2 - 18/01/08

Now the rockwool blocks have been soaked I get the planting area prepared. When propagating my plants i keep the temperature in the growing area between 22-25c and the relative humidity between 65-75%. Young plants respond and grow very well in humid environments. I use 110w fluorescent lamp on for 18 hours a day to supplement the natural light entering the greenhouse.

After the transplant blocks have been pre-treated they need preparing for the seedlings to be planted into. Rockwool holds allot of water so after soaking excess needs to be shaken out or lightly squeezed. I Shake a few times then lightly squeeze (squeezing heavily can damage the structure of rockwool). The blocks want to be damp but not too wet. You can tell when they ready by squeezing the corners lightly, if no solution drips out your ready to plant in.

Once the blocks are all ready I insert each propagation cube into their blocks. I make sure the cubes are firmly in to avoid leaving gaps between the cube and the block.



To avoid algae growing on the surface of the rockwool blocks i cover them with squares of black and white plastic. You can cut them your self but i buy pre cut squares as they are cheap and saves loads of time. Another good thing about the white plastic squares is you can use them as labels to identify the plants too.

I always put my plants growing in transplant blocks on a raised mesh so air can move underneath them. This slight movement of air under the blocks stops roots growing out and concentrates the root growth within the block, this is know as 'air pruning'. I use to place blocks on a growing media such as perlite or vermiculite in a tray but this encouraged the roots grow straight out the block and into the media. When the plants were moved the long roots out of the block inevitably got damaged. These young damaged roots would often die back not getting the plant off to a good start so now I always use air pruning trays until the bottom of the block is covered with root tips. This always gets plants off to a explosive start with less chance of transplant shock when planted into its final hydroponic system.

Sowing the Seeds - 09/01/08

January's the time I sow the seeds of my main crops which are tomatoes, chillies, peppers and cucumbers. For propagating my seedlings I use Grodan Rockwool cubes and 'Fleximix'.

'Fleximix' is a peat/pine bark based spongy cube bound together using a plant based polymer. It has a great air to water ratio suitable for seeds and cuttings. These cubes are taken straight out the bag, put into small trays and wet using a spray gun. They come slightly damp but often need a bit more wetting. You can squeeze off any excess water applied as they easily spring back to shape. They already contain some plant nutrients so do not apply any more at this point.














Rockwool cubes are made from heating up volcanic rock into liquid and spinning it like candy floss into blocks. These are then cut into shape. Rockwool contains no nutrients for plants so needs pre-soaking in a mild nutrient solution. I use 'Vita Link' Plant Start at the recommended dose which is high in all the nutrients young plants need. I also use a liquid formula of beneficial microbes , fungi and bacteria called 'Bio Link Plus'. This stuff smells so bad but is great at producing a great root system.

Rockwool should be soaked for at least a few hours but overnight is preferable. Rockwool is also slightly alkaline so before soaking check the soaking solution is around pH 5.5 (near the lower limit which plants can tolerate). I find after mixing the 'Plant start' and 'Bio Link Plus' the pH falls around 5.5 so no further adjusting is necessary. After a few hours the pH of the solution will raise up to between 5.8-6.0 which is considered optimal for plants grown in hydroponics. When I take the cubes out of their soak I give them a few shakes to get rid of any excess solution. Saturated rockwool can hinder germination and welcome diseases. Another way to remove the excess is to lightly squeeze the cubes but I find this can disrupt and compress the structure of rockwool so prefer to shake them.














After the propagation cubes are prepared I write all my labels and make small holes 1 or 2 cm deep for planting the seeds into. Once the seeds are planted into the holes I lightly close them back up to keep the seeds dark. When using fleximix I fill the pre made holes using some fine compost, coco coir or loose bits of fleximix.














Once all the seeds are sown and the trays are labelled I place them in a large propagator heated using a Thermostatically controlled heating mat. On the base of the tray I use dampened Vermiculite or Perlite which spreads the heat evenly in tray and holds water to keep the propagator humid. Seeds germinate quickly in a heated propagator which is essential if your growing area is a bit cold. I try to manitain the propagator around 24c and above 85% Relative Humidity. I find this gives me good results especially for chillies and peppers. Hanging above the propagator is a 110w fluorescent twin lamp (2 x 55w bulbs) which doesn't use loads of electricity and brings on the seedlings extremely well once they pop up.















Once the lid is closed the humidity soon builds up inside. Now all I can do is wait and see. Hopefully in 1-2 weeks I'll be ready to transplant them!