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.