Striking a cutting in water is not a good horticultural practice (you'll rarely find it in any textbooks), although it can be done. It's especially not good for woody cutting, such as lavender.

You're best to propagate cutting in some sort of soil - I use ordinary potting mix, but you can get special propagating mixes. The reason soil is better is because soil is the plant's natural environment, and also such roots as are formed are specialised for taking in water, not other nutrients which are found in soil. Woody cuttings especially have a tendency to rot in water, too.

I never recommend people strike cuttings in water. You almost always end up with a less-than-perfect plant, because it has to go to so much trouble once planted to produce all the roots it needs. If you absolutely insist on doing it this way, you take the risk of encouraging diseases such as fungi. You must make sure to change the water every day.

For woody cuttings like lavender you're best to take a heel cutting. See link below. It's very simple. Just dip the cut end into some pure honey (or rooting hormone if you feel extravagant!), dibble a hole in the soil with a pencil or similar, then put in the cutting, and gently tamp the soil around it. Give it a light watering, and off it'll go.

It can take several weeks for the cuttings to strike, but they'll be good, healthy ones. Keep the cuttings warm, don't overwater, and don't feed them. I like to remove most of the leaves - I cut parallel to the stem, removing about half of each leaf, and I chop off its head!

Here is a link that might be useful: taking a heel cutting

Thank you so much Daisy! I didn't realize that. All these years I have been 'rooting' plants in water too.

We moved two provinces last August to 15 acres. I inherited a large perennial flower bed as well as a garden about an acre! There is also an atrium on the front of the house so I inherited plants as well.

With all this room I decided over winter to pursue my passion of herbs, which would explain all of my sudden postings! I have to pop over to the flower section as well as I have all these beautiful flowers out there and I am not sure what they all are, or how to care for them.

I appreciate your tip and will check out that link. I'll let you know how I make out!

Sincerely
Tamara

Thanks so much for the info! I have already bought several lavender plants and want more- maybe I won't have to buy them. Thanks! Brandy

Very good article!!!.

I will try the honey thing. I have planted 2 lavender plants(kew red varieties) with the intention of striking and making a hedge. One of the plants died and I have been unsuccessfully been trying to strike cuttings from the healthy plant for weeks. Even with the hormone powder.

The strange thing is one of my lavenders was dying branch by branch. It is growing in the same position as the other, in soil treated at the same time and watered together. All in all the full plant died before my cuttings died.

If there is any reasons why you think the lavender died I would like to hear them. I couldn't find pests, fungus or anything else......unless my housemate poured a mop bucket over it...... Infact that is the most likely thing to happen.