I do a lot of Vietnamese cooking at home, and the unique flavor of lemongrass is one of my absolute favorites. When I discovered you can propagate lemongrass from stalks bought at the grocery store, I drove right down to my local Asian market and picked up six fresh stalks to root in water.
This method is pretty much fool-proof. The stalks you buy don’t need to have roots at the bottom, but they do need to have the entire stem intact.
I cut off the foliage, leaving only an inch above the stem. Choose a sunny location like a south-facing windowsill, put the stalks in water, change the water every day, and watch as new leaves begin growing almost immediately. The roots start emerging after a week, and the stalk eventually divides itself (via offshoot stalks) after a few weeks. Once the roots reach a sizable length (at least three inches), the stalks are ready to go in the ground.
In the first week, new leaves form at the top.
Roots after one week.
Roots after two weeks.
And finally, three weeks later with sizable roots and new foliage growth, the lemongrass stalks are ready for the garden.
I planted three stalks together for a larger yield, but if growing in a container, one stalk will do. Under ideal conditions, lemongrass will grow into a very hefty shrub, about five feet tall and wide, or even more. It can become so dense that some people even grow lemongrass as a screen or hedge… so pick a spacious permanent area in your garden for it.
Lemongrass is a perennial that likes moist soil, a warm climate, and sunny location (picture its native tropical conditions) and overwinters in my Sunset climate zone 24. The stalks should be ready for harvest in two to four months, and will grow back if you snap off or cut the stalk about an inch above the ground. You can also cut the stalk away from the plant (with rootstock intact) to propagate more plants. Share them with your friends!