Now that some of the cuttings have started to make root you will have to start to think about potting them up in to individual pots. The best type of pot I find as I grow a lot of cuttings is the 4 inch square pots as they take up less room in the greenhouses. The first cuttings always take the longest to root as the days are short. When the cuttings have rooted they are knocked out of the pot. I pot them up in a compost mixture of half multipurpose compost and half horticultural grit sand the grit sand helps to keep the compost open and allow some weight to the pot so the pot will not dry out to quickly, and the roots should be stronger If you do the mix this way when you finally plant out in to the open ground the plant will get away more quickly than if you just plant them in multipurpose compost with no grit in this way you will find that the plants root are soft and fibrous and will be slow to get away in the open ground. Separate the rooted cuttings from each other trying not to knock to much compost off them, then half fill the pot, take the cutting by holding the main two pair of leaves try and hold it in the centre of the pot place the compost around the cutting trying not to break any of the roots as this will knock the plant back until it makes more root. Gently firm around the cutting then give it a good drink. At this stage don’t forget to put the label in the pot, if you don’t you will get mixed up with all the different types and you will have to wait until it flowers before you can name it. Then place the pot in a cool shady part of the greenhouse for a day or two until the plant gets established. Do not water the pot until it starts to dry out, if you give them too much water at this stage you will find that the small roots will start to rot. If the weather is fairly sunny it will be advisable to put some newspaper over them just to take the bite out of the sun. Continue to take cuttings until you have the amount you require. As time goes on keep potting the cuttings up to build up a stock. As the greenhouse starts to fill up you can move the first lot of plants to a cooler place, the ideal spot is a cold frame to harden them of before they are planted out in the garden. Through the day you can leave the frame tops open slightly to let some air in If we get some cold nights they may have to be covered with an old blanket or carpet to keep the frost of them.
Don’t forget to spray for greenfly and the dreaded slugs as they love the lush growth of the dahlia plants tender green leaves and stems.