The pips you get off a head will vary depending on the quality of the head, some will be very small whilst others will be a few inches tall. There will also be few that are bent or curved as they have projected from the lower end of the head and curved upwards in search of light.
I have the best heads of leek bulbils or pips that I have had for many years and this coming weekend I shall start to remove some of them from the heads ready for striking in the compost in trays. Before that though there are a few things to attend to and this is usually carried out in the evenings before I start to prick them out. Once the heads have been removed with a short stalk they are then taken indoors on a seed tray lined with some tissue paper for the pips to be removed.
Each bulbil is carefully removed making sure that the root plate is nice and white and not brown and corky. The latter type of bulbil rarely root well and are always prone to trouble with many collapsing, often weeks after the initial rooting period. Once removed, the outer dry small flag, together with any outer tissue, is removed so that there is even less danger of any disease getting into the compost. As a last resort, and to make sure the young plants have a good start, the bottom end of each are dipped in a fifty fifty dilution of normal household bleach.
Generally if the pips have been sitting maturing on the head for a few weeks too many, they will usually fall off on their own accord. Indeed with those you have to be careful that you don’t loose some of them during handling. Conversely if the heads are young and fresh and just approaching maturity, they will still be very much attached to the head and I may well have to revert to using a sharp thin bladed clean knife to cut through the head. This is done by pushing the blade in from the stalk end and gently rocking it back and forth until the head splits in two.
Once the head is in two pieces it”s easy then to quarter it and the pips can be removed cleanly together with their root plate. If you do not carry out the above and try to forcefully remove the pips from the head a number will inevitably snap off leaving the tiny root plate behind. This means that if you try to root those pips they would just collapse and die whilst at the same time cause concern regarding the spread of disease amongst those young plants trying to root.
One problem I noticed that I had bad this year was some large postules of rust that developed on the leek stems which if left unnoticed the spores would most certainly have settled on the young pips. Fortunately I have kept the heads absolutely free from rust and have managed to contain it on the stalk by spreading Vaseline all over the stems to contain the spores and prevent them from spreading. Once the heads have been removed the whole stalk will be cut away at compost level and disposed of in the dustbin.
The pips you get off a head will vary depending on the quality of the head, some will be very small like the ones on the right hand side of the picture whilst others will be a few inches tall like those on the left. There will also be few that are bent or curved as they have projected from the lower end of the head and curved upwards in search of light. These must be planted with the lower section of the bulbil perfectly erect it doesn’t matter if the remainder of the foliage is hanging over onto the compost. These can be trimmed back if necessary and very soon the young leek plant will be standing bolt upright.
The compost I use in the trays is either Levington F2 or F2S, I prefer to use the latter, if I have some spare, as the ‘S” stands for added fine sand which is ideal at this early stage to create a good strong root system. If you can’t get the above compost, then use some Levington Multi purpose, pass it through a quarter sieve and add some fine silver sand to it, just enough to open up the structure of the compost. The plants will be carefully watered and then left to grow steadily on the propagating bench with a little bottom heat. They will not be subjected to any artificial lights at this stage and the greenhouse heating will be set fairly low.
What I don’t want at this stage is some very early growth, they have a long way to go yet and I want them to peak during late August September rather than in July. As the majority of the heads are really fresh and green, I won’t be in too much of a hurry to prick them all out and I hope to be able to do some towards the end of the month even to see if it they will mature later.
Once the plants have been watered in, don’t be too hasty to water again, they are not water lilies and as they are striving to develop a root system they will hardly be transpiring, so they won’t need too much water. Indeed water is probably the biggest carrier of disease in any greenhouse so I do make sure that my water butt, which is always inside at the same temperature as the plants, is kept perfectly clean and once filled with water some Armillatox is added at the propriety rate to maintain freshness and prevent any fungal spores from getting established in and around the plants.