The first part of our three part article series about lavender multiplication is about cuttings. Let’s clone lavender!
One of the popular methods of lavender multiplication is cuttings, when we essentially reproduce the mother plant, we clone it, if you will. The basic meaning of the Greek word klon is twig, branch anyway – so we are not creating some wild gene manipulated monsters, we simply copy the plant. This type of multiplication is called vegetative or monogenetic multiplication. Its great advantage is, that we can “manufacture” new plants in large numbers in a small area, which in their properties are exactly and certainly identical to the original plant. We have two possibilities, depending on if we pick the new specimen when it has already taken root, or when this hasn’t happened yet. The latter is cuttings: we cut a shoot of the plant off, which we root, and we manufacture its exact copy in this way. The former possibility is multiplication by planting layers, which we will mention in the next article.
Spring is perhaps the most fortunate time for cuttings, at this time we should cut one year old, healthy, already woodened shoots off an at least 4 year old plant, or green shoots in the end of summer.
The great advantage of spring propagation is that the nicely strengthened lavender can be planted into its permanent place in the autumn. In the case of autumn propagation they have to be covered against the cold in the winter, then they can be planted out in the open soil in the end of spring. About the proper length of the new lavender shoot there are differing opinions, 4, 3, 2,5 inch (10, 8, 6 cm), but we have seen smaller shoots as well.
We try it with several size variations
The point is one thing, from the lower part of the stem we simply pull the leaves down with a single motion, with this we immediately half the vaporizing surface. We cut the shoot off right under the bunch of leaves. Some swear by the 45 degree cut, because this is how the cut surface is the largest and the root formation will begin on this “wounded” part.
In high (80-95%) humidity, evaporation on the remaining leaves is a lot smaller, besides in humid air the foot rooting of the shoot is faster, as well.
A very simple “measuring device” – we should keep humidity within the range.
The first 2-3 weeks, until the root formation begins is definitely a critical period. For the long term maintenance of humid air we don’t necessarily need a greenhouse, even a one metre transparent plastic bag or a preserve glass will do, with which we catch the humidity, but we provide light.
We put a transparent IKEA box over the propagation tray, so we can take care of the little shoots comfortably and easily.
The recommendation of specialized books and gardeners is the well washed common river (the grey coloured) sand, or a mixture of perlite and peat, in some people’s case simple screened flower-mould or gravel has worked. Neither sand nor perlite contain nutrients, but the plant doesn’t even need that in the beginning of root formation, the plant draws away the “energy” it needs from itself, however in the case of these substances is the chance the lowest, that some kind of infection will affect the shoot, in which case its part in the soil will simply rot. There is also a method where the soil of the shoot is layered, the top layer (2 inch - 4-5 cm) contains grey sand, the bottom layer common garden soil, thus the root formation starts in the relatively sterile sand, and the growing root network reaches the soil in time, from where it can take up nutrients as well. We tried a few variations from substances we could quickly find at home- sand, different ratios of a garden soil and flower-mould mixture, and later it will turn out which was the most fortunate one.
We can put shoots in small or large pots, boxes, propagating trays. We should condense and water the soil before placing the shoots in it.
Theoretically root forming hormone is not absolutely necessary, but a lot of people recommend it, so we tried both methods. We dip the foot of the shoot in root forming hormone. We used root forming powder, it costs 5-6 $, for semi-woody cuttings.
We prepare a small hole in the soil and we stick the stem of the shoot about 1 inch (2-3 cm) deep and we condense the soil around it with two fingers. A leaf should absolutely never get under the soil, because if it rots it may ruin our work. We can easily plant the shoots densely as well, the point is that they shouldn’t touch each other.
The development of the entire root could take as long as 4-6 weeks, we should keep the vicinity wet, but it shouldn’t be squelched. If the plant has managed to take root can easily be determined, if its leaf is pale and dangling it surely has not. If it has the leaves stand confidently and even brings sprouts, and in that case taking root is certain. During the phase in between the two, only expectation remains (and watering, and humidifying).
We should put the little plants in a shady place, in the sunlight, especially with glasses or bags over their tops, they would fade quickly.
There are also two odd ones out among the bunch, bright blue shoots that are of an also aromatic and fragrant spice plant, the rosemary. The final result is a nice little lavender which has taken root.
Photo: Flickr, graibeard cc2.0 licence