The drawback of growing hemp plants from seed is the large variation in quality. To ensure a high quality average score, the grower needs to severely select from the largest possible number of plants, from which he’ll actually be able to grow his crop essentially for nothing. The big advantage to growing hemp plants from seed is that there are always plants that are clearly better than the others.
The higher the number of plants from which the selection can be made the better the plant will be. By only raising the best plants to maturity from seed, the grower can improve the quality of his varieties year on year. The problem remains that the plants the grower uses for the production of sinsemilla have a wide range of differences between them. Of course it would be ideal if all plants from a particular harvest were as good as the best plant from that year or if need be from the year before.
Clones fulfil this need, because they are the cuttings from a female super plant; all of them genetically identical to each other and the mother plant from which they originated. Clones cannot be improved or worsened in quality by the genetic lottery of sexual reproduction, but just deliver the same level of quality, year after year. There are known instances of clones that have been reproduced 50 times in succession, without any loss of quality (provided of course that the clones were all taken from a healthy specimen).
Fill the pots with the mixture, make them good and moist then place them under the lamp in order for them to come to the right temperature. Rooted clones do not so much need light they do as warmth for them to develop their root system. Keep the root temperature at a minimum of 20 degrees Celsius, preferably 25 degrees. For this use a soil warmer (small mat or cable) or keep the air temperature a few degrees higher than the desired root temperature. For measuring the root temperature use one or more aquarium thermometers (costing 2-3 Euros each). Tip: when buying, always place a few next to each other on the counter and only buy those meters that give the broadly same reading as each other.
Slice or nip off some good looking growing tips from the desired plants. Don’t cut them too small or else their chances of survival will be lowered; make generous cuttings of 5-10 centimetres in length. If you’re taking clones from plants in the field then always take more cuttings than you think you’ll need, just to be on the safe side. Since you’re not yet sure which plant will be the best, you can best take cuttings from a number of different plants.
Immediately remove the largest leaves from the new cutting, since these evaporate too much moisture. Tie the clones from the same plant together and label the bunch and put them straight into a bucket of water to prevent them from “fainting” from moisture loss. Once in the bucket the clones can be kept for a day or two but it is still best to get them planted as soon as possible.
You must give the clones light 24 hours a day. You can think of the whole thing as a sort of intensive-care unit; you don’t turn it off at night! After ten days to two weeks you’ll be able to see the first roots poking through the base of the pots. If you’re using small pots, then it is time to take them out of their incubator and plant them. Cuttings in larger pots can stay a while longer until they’re a bit bigger. TIP: make the pots good and wet before you replant; the little roots can then easily grow through the moist, paper-like peat dust.
Only bother to re-pot the best specimens. If you’re working with various varieties of plant, label each clone clearly right at the start. Rooted clones can be re-potted in bigger pots (10-20 centimetres diameter).
Make a small hole in the pot’s soil with a pencil or nail. Dip the bottom end of the cutting in some hormone powder and carefully tap off any excess powder. Plant the cutting carefully in the hole and press the soil around it gently in, giving it some water if it looks like it needs some. Especially during the first week, keep the clone good and moist. Give the clones leaf nutrition regularly, if possible by spraying them with the plant mister (into which you’ve dissolved a teaspoon of fish emulsion per litre of water). After each leaf feed, spray them later with pure water to clean the leaves.
There are also small rock wool blocks you can use as a cutting medium. These work no better than peat dust, are much more expensive, environmentally damaging (they don’t perish) and you have to use them the moment they’re ready. That said, they are better if you need to transport the clones; you can even drop them without causing damage, which is not something you want to try with peat dust plants. They are also quicker and easier to use. You just lay them on a bed of perlite, so that air can get underneath them, and soak them with water into which some rooting hormone has been dissolved. The blocks come from the factory with holes ready made, into which you stick the cuttings. Press them a little bit further down into the block, so that the cuttings are standing firmly upright.
You stick the cuttings into the peat dust or rock wool blocks and spray the clones once with root hormone-laced water. A litre is sufficient for several sprayings over the first 48 hours. The hormone percolates through the cell walls of the clone - and Bob’s your uncle! If you’re a natural purist, then take some willow twigs and make a hormone-containing extract or place the stem in your mouth to wet it with saliva, which also seems to work.