We all love our lavender plants, for their beauty, flowers, and smell. Why not grow too many plants? This simply requires a few easy garden supplies, and a lavender plant to source your cuttings from! While I do not endorse snipping cuttings from neighbors plants, this is exactly what happens.
Step 1: Get Your Cuttings
Select a healthy stem from an established lavender plant, or use compost/greenwaste from trimming plant. My method is one of high numbers, high attrition, so get a lot. You want to use singular branches that have a gradient from woody section to green to leaves, and trim off any flowering section to avoid wasted energy.
Step 2: Optional: Rooting Hormone
I cannot tell you how effective this method is, but I highly recommend trying it out. Any local garden store or junk pile in your garage will have this stuff, and it's handy to have around. Apply as instructed to a leaf-stripped wood-green section.
Step 3: Plant
In a mound of dirt or planter box or pot, plant the cuttings mostly into the dirt to maximize contact area, leaving just a little bit of the leaves and growing area exposed. This will give each branch maximum nodes to grow roots from. I recommend using any dirt that holds moisture well.
Make hole with trowel/hand > place branch in > cover with dirt > repeat
Now, keep it properly wet, as the growing medium should always remain moist, and keep in shade to encourage root growth over photosynthesis.
Ideally, the branch will send out shoots that will become root systems, and you'll notice this as the leaf area starts growing again, or even blooming.
Step 4: New Lavender Plant
Now you have successfully created clones. A new plant to decorated your yard to attract bees! Transplant, but understand these plants while very hardy, have sensitive young rootballs and may take a bit to grow large. Enjoy!