Posted: 26/02/2014 at 09:36
I've had this on file for yonks, I thought I'd post it so those interested in growing those long stemmed, exhibition quality sweet peas can see how it's done.
"How to grow using the cordon method:
This is the method favoured by exhibition growers and anyone wanting to grow top quality flowers. It requires more time with a commensurate improvement in blooms. You will find that you will have fewer flowers using this method than growing naturally but they will be of much better quality.
After planting out leave your plants for around 4 to 6 weeks to settle. After this time, depending on the local weather conditions, they will probably be at least 12 inches (30cm) tall. Restrict the growth to one shoot by cutting or nipping out the extra shoots and tie the remaining shoot loosely to its support. You might want to use metal rings to tie in your plants as these tend to be quickest overall but anything will do. Continue to nip out side shoots which form at every leaf axil, tying in the plant as necessary. You should also remove the twisty tendrils seen at the end of the pairs of leaves which form up the stem. It is rather like growing tomatoes on the cordon. Do not allow flowers to set seed. Most growers cut them as they open which means one stem per plant every day or every other day, depending on weather conditions. Many growers will also nip out the early blooms as they form to further strengthen their plants, doing so until the blooms start to form with four florets per stem or until June.
Growing on the cordon means that all the plant's energy is concentrated into producing better flowers and growth of the single branch. This means that your plants will soon reach the top of your canes. You will then need to 'layer' them. Do not confuse this with propagation – all this means is to drop your plants down to the bottom of the canes so that they can grow up again. You may need to do this more than once during the season. The easiest way to layer is to undo the ties and gently lay your plants horizontally along the rows. They will naturally turn upwards in a day or two and you can then tie them in to the nearest cane and continue as before. You may choose to tie train them up a cane further along the row straight away. Take care not to snap the plant as they can be very brittle. Choose a warm day and make any bends gradual."
Growing for cut flowers is much easier.