A while ago I said that I would show you how I take dahlia cuttings, this also applies to certain other plants that will root from softwood cuttings. First of all you need to make sure you take the cutting from new growth and preferably with no flower, if you do end up with a flower attached pinch it off. You really want to be taking the cutting from just above a joint in the stem so that you have new growth of 3 to 4 inches long as below. The number 5 on the label you see is just to tell me the name of the dahlia. Rather than having to write Border Princess on every label I find it easier to give each variety a number as its easier to write down. I have a paper with the list of names plus a picture of the flower and the number I've given it so all I have to do to see what number 5 looks like is look it up on the paper. In this case Number 5 is actually 'My Love' and is medium sized white dahlia.Once you have your material take it to a hard surface and trim off the stem to just below a joint as in the picture below. Use a very sharp knife as the cut needs to be a clean as possible. I use a modeling scalpel.
When you've cut off the stem below a joint remove the lower leaves leaving just 1 or 2 big leaves plus the growing tip as in the picture below. You can also see from this picture that the cuttings are about 3 inches in length.
Now fill a small pot with compost, I use a mix of half potting compost and half sharp sand but if you don't have the sand just compost will do, try not to over water it though. I add the sand to help drainage. Now push the cuttings in around the edge of the pot as you see in the picture below and then gently firm them in before adding a little water. They then need to be put somewhere bright and warm but out of direct sunlight. I pu mine in the warm greenhouse behind taller plants. A window sill in the house should be okay provided it doesn't et full sun on it.
A good idea with some plants is to put them inside a plastic bag as below. You do have to be careful of rotting if you do this though and its not something I would do with such as geraniums which are prone to rotting off at the best of times. It does seem to help with dahlia's though as they tend to droop all over the sides of the pots if not done like this.