If you have just bought some great new plants and want to multiply your collection for free here is a useful step-by-step guide on how to do it. Basal cuttings work with lupins, delphiniums, dahlias, euphorbias and many other similiar plants. We bought these lovely looking lupins which were going to be perfect in our cottage garden in Devon. We wanted to get more of these plants without paying a lot of money, cuttings was the best, cheapest way to do it. The reason why you should take a basal cutting is because lifting and dividing the plant would disturb it too much and if you have young plants there isnt much to divide.
To take a basal cutting you need a sharp knife. Find a young but strong shoot (short and stubby shoots are ideal) and cut it diagonally under the soil as close to the rootball of the plant as possible. Take the bottom leaves off, if there are any there, and if there are fresh new shoots appearing from the top, pinch them off. This will make the new plant put all of its energy into making new roots and by taking off some leaves, stop it from drying out.
Put the cutting into a gritty compost which has good drainage and place them around the edge of the pot to give it the best start. Give it a good soak and spray the plant when needed. For the first few days the cuttings will wilt, but when they start standing up straight you know that they are growing new roots. You can use rooting powder if you want, but I don’t bother and don’t think it makes much of a difference. If you are doing it this early in the year when it is cold or when it is very dry, put a plastic bag over the pot. This will keep the cutting warm and condensation will keep it from drying out. When the plant has rooted well and is showing signs of new growth, remove the bag and put it in a warm spot e.g. a greenhouse or indoors on a sunny windowsill.
When you see roots coming from under the pot, pot each plant up individually. This is why you put the cuttings near the side of the pot, to give it better drainage and to see clearly how well the plants have rooted.
Its now a month since we bought these lupins and the parent plants have doubled in size and the large cuttings (which had a bit of root attached) are the same size as the parent plant and the smaller ones (the one in the picture) has new leaves emerging and is growing bigger and bigger.