Notes from Windward: #68

Propagating Lavender

Annie describes her research into rooting lavender

April 10:

It is springtime, and we are looking to expand on our lavender field, so it is time to propagate!

**me and one of last year's plantings**

Lavender Propagation:

Cut tender shoot that is around 2-4in long with around 3-5 nodes.
- Avoid woody stems
- Cut just below the last node
Remove 1 or 2 sets of lower leaves with your fingers.
- These heels are where the roots should come out
This next step is where I am going to experiment a little. After reading much about what sort of rooting compounds to use I am going to try using two different rooting compounds and then grow some without any root stimulator to see if there is a need for any additional help at all. I will plant them as so: 4 shoots dipped in honey, 4 watered with a store bought rooting hormone, and 4 with no added rooting compounds. (what good is a psych. major without a little research?)
Place shoots in prepared soil mixture with about 1/3 of the shoot buried and water
- I used one part perlite, one part sand, and a bit of compost.
- I have searched the internet; and different websites have recommended different combinations of perlite, peat moss, cat litter, and sand…..so I would say whatever is best available to you, but keep in mind that lavender thrives with good drainage!
I read from one source, Dr. Kawase, to place the shoots in complete darkness until rooted, so I put half of the shoots in the dark and the other half in light the propagation greenhouse.
Once rooted, move outdoors for a few hours each day
When the shoots have reached 3-4 times their size, plant in a sunny, well-drained area.

So, in a few days, we will get to see which ones have rooted well and which method works the best. I am eager to find out!

Important notes:

Cuttings are best taken in spring when there is nice green growth on the plant. Woody stems do not root as well as new growth.
Lavender likes neutral or slightly alkaline soil
Lavender can be planted as a deterrent towards deer
It is drought tolerant, so don't over water!
Another possible rooting compound is willow water. One way willow water is made is by taking a few branches of willow trees, chopping and mashing the branches up, and then placing the pieces in very hot water. Once the water is cooled, it should be ready to use. Of course there are many other ways to make the water (but this one seems the easiest), so I would recommend experimenting a little. There are no willow trees around Windward, so I wasn't able to experiment for myself.
Willow water is used because it has two naturally occurring hormones in abundance that counter a plants' wound control response after it has been cut, one is salicylic acid and the other is rhizocaline, which both promote root growth.

May 20:

It has been a little over a month since I first propagated my lavender. First, a little recap on my procedure. In April, I went out in the luscious lavender field to pick some lavender stems. After some researching, I discovered there were a few different ways to propagate lavender, and of course each website thought its method was the best and only way. I decided to experiment with all the different techniques and see what works best for me. The constants were the amount of water given to the cutting and the soil mixture. Half of the cuttings went in complete darkness and the other half were in the light in propagation greenhouse. The other variables were the different types of root stimulator, which was subject to vigorous debate on the internet. I put a third of the plants in a store bought rooting hormone, another third were dipped in honey, and the last third had no root stimulator.

A month later, I checked to see which ones made it. Almost 20% of the shoots left in the dark survived and nearly 40% of the shoots in light survived. Of the shoots in the dark, half of the honey dipped survived, half of the rooting hormone ones survived and none of the shoots without any hormone survived. Of the shoots in the light, none dipped in honey survived, all of the shoots treated with rooting hormone survived, and a quarter of the shoots without any rooting hormone survived. I am still going to give the survivors some time to grow a tad more before I transplant them in our lavender patch.

According to the results, it appears a store bought rooting hormone worked the best for my shoots. I was a little disappointed, I was "rooting" for the honey, a more natural substance, but the shoots thought otherwise. The shoots without any added help, I was somewhat expecting not to do so well because of everything I read on the internet about the need of a rooting hormone. The shoots in the dark trial did not do as well as the shoots in the light trial, perhaps because of the long duration they were in there. I also think one of the reasons the shoots did not do as well as I had hoped is because I may have propagated too early in the season. The shoots were not as green as they are now. We had a lingering winter here at Windward. May seems a prime time for propagation compared with chilly April.

I feel after my first trial, I have learned what works for my lavender cuttings. This time I took greener shoots, placed them all in the rooting hormone and placed them in the light. A month later, hopefully we will have 100% success rate!

Notes From Windward - Index - Vol. 68