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DIY Hydroponics - Seeds or Cuttings?


When a plant grows it usually will have three stages of growth. The seedling stage is of course first and covers the time between the plant first germinating and when it is well established and capable of growing well. The vegetative stage is a midway point, the plant once established will enter into a state of prolific growth with its objective being to be biggest plant that its growing conditions, species etc will allow. Finally, upon change of photoperiod or at a genetically predetermined size or age the plant will enter the flowering stage and produce male or female flowers depending on its gender and species and procreate. After the flowering stage some types of plants will die and others may go into a state of dormancy in preparation for another year of growth.

The seedling stage is a delicate time for a plant and great care should be taken with seedlings to ensure they remain in good health.

In a hydroponic garden there are a number of choices as to how we can restock the garden after a successfull crop and this will determine how fast we can produce more productive plants and harvest more flowers, vegetables or whatever. Many clever gardeners have a seperate section for their seedlings and time their gardening so that as one set of plants complete their flowering period another set of seedlings is ready to be moved into the garden from the nursery. The main hydroponics system is cleaned and sterilized, new media is placed in the growing containers or trays and the seedlings are potted up and into the main garden. There are three main ways you can create young plants to move into the main garden.

humidicribCuttings are a fantastic way to purpetuate a favourite variety or individual plant. When you take a cutting you are cloning the parent plant and the new plant is genetically identical to the plant the cutting was taken from. It also has the advantage that if taken off a plant in vegetative growth the cutting once established will be faster to enter vegetative growth itself. To take a successfull cutting you will need a sharp pair of scissors, a scalpel, a bowl of tepid water, some cloning gel, a rockwool cube and a humid chamber such as a horticultural humidity crib. The humidity crib is essential for a good cutting success rate. They are really just a seedling tray with a clear plastic top with adjustable vents so that the humidity level can be adjusted within the humidity crib.

To take the cutting select a suitable part of your parent plant that is about 3-5 inches long and has at least 2 different leaf nodes (where sets of leaves join the main stem) and with the scissors cut at least an inch below the lowest set of leaf nodes and quickly place the cutting you have just taken into the bowl of water so that the cut is well covered below the waterline. This prevents an air bubble forming in the newly cut stem. While the cutting is underwater cut the stem at a 45 degree angle with the scalpel about 1/4 of an inch below the lowest node once again so that the cut made with the scissors is removed. Gently rub the stem of the plant around the lowest leaf node with the scalpel to rough the surface of the stem up slightly and then quickly lift the cutting out of the water and place it into the cloning gel so that the cut and the node you have roughed up are covered by the cloning gel. Let it sit for a moment in the cloning gel. This cutting should then be placed into your rockwool cube. Prepare the cube by soaking it in water for an hour and then rinsing it thoroughly (do this before you take your cuttings of course) and create a hole in the top of the rockwool cube slightly larger than the diameter of the stem of the cutting you intend to place in it and about an inch and a half deep. Place the cutting into this hole and then put the cutting into the humidicrib with the vents only open a slight amount. Spray the cuttings with water twice a day with a spray bottle that is capable of a fine mist for the first week. After the first week the cuttings should be starting to create roots so open the vents on the humidicrib halfway. After another week you should see roots poking out of the side of the rockwool cube and the cuttings should start to sprout leaves.

Raising Seedlings is generally slower than taking cuttings but is more likely to be successfull on the first attempt. Rockwool cubes are the best choice for seedlings, simply soak the seedling cube for about an hour in water and then rinse it thoroughly. Create a small hole in the cube about 1/4 inch deep and place your seed into it. Make sure that the hole gives the seed room to move as if it is too tight the seedling will not be strong enough to emerge. Keep the rockwool cube moist and in a warm place. Once the seedling germinates keep watering it with plain water until its first set of leaves are fully spread open then start with 1/4 strength nutrient solution and slowly let it get used to stronger nutrient over a period of several days. When the seedling is well established and there are roots popping out of the side of the rockwool cube it is ready to move to a larger container or hydroponic tray.

Buying Seedlings in punnets from your local nursery sounds like the easy way out but I have found it to be the most economical solution. Most seedlings commercially grown these days are grown hydroponically anyway and arrive in a healthy robust condition suitable for placement in your main hydroponic system after only a few days. When you buy them put them into a seedling tray and give them a 1/2 strength nutrient solution and place them into your garden so that they may become acclimatised before you pot them up. This will reduce the stress on the seedlings and when they have settled in they will be more receptive to being potted up.

Regardless of how you choose to obtain your new plants a seedling tray will be of great use to you. A seedling tray is just a plastic tray that has no drain holes and has sides around 1-3 inches high. Place your seedlings or struck cuttings into this tray and fill it so that there is just enough in the bottom of the tray for the seedlings to become moistened by capillary action. Rockwool is the best option for seedlings however a 4:1 vermiculite/perlite mix can be nearly as effective. Seedlings prefer to be moist but never saturated and they most certainly dont like being dried out completely.