Propagate Lemon Grass: Fast Root Growth in Water Without Soil

Lemon grass roots take off in water faster than you’d expect—within 2-3 weeks if you follow the right steps. 🌱 I’ve propagated dozens of stalks this way, and the key is keeping the water fresh and the light bright.

No soil, no fuss, just watch those roots grow like crazy.

The only supplies you need are healthy lemon grass stalks, clean water, and a jar or glass tall enough to submerge the bottom third. Skip the soil entirely—this method works best when you let the roots develop in water first before transplanting.

Most people overthink it, but the process is simple once you know the tricks.

By the time those roots hit 2-3 inches, you’ll be ready to move them into soil and watch them shoot up into full-sized plants. The fragrance alone makes it worth the effort, but the speed? That’s the real game-changer for impatient gardeners like me.

Works for both indoor pots and outdoor beds, and you can propagate year-round in warm climates. Here’s how to avoid the most common mistakes and keep your cuttings thriving.

What you need

How to propagate lemon grass with rapid water roots

Here’s the quick method I use to grow sturdy lemon grass stalks in water—no soil needed.

Choose thick, mature stalks with 3-4 inches of growth—they’ll root fastest. Look for stalks with tight, green leaves at the top and no brown or mushy spots at the base. These are your best candidates for strong root development.

Using clean, sharp scissors, cut a 4-6 inch section just below a node (the little bump where leaves grow). This node is where roots will sprout. Trim off any yellow or damaged leaves to reduce stress on the new plant. Here’s the thing—don’t skip this step. Dirty or damaged cuts slow down rooting and invite rot.

Fill a clear glass or jar with room-temperature water—about 3-4 inches deep. Clear containers let you monitor root growth, which is especially satisfying (you’ll see roots in 1-2 weeks). I like to use a mason jar because it’s stable and easy to clean between propagations.

Place the trimmed stalk in the water so the node is submerged but the leaves stay above. The leaves should float slightly—if they’re fully underwater, trim the stalk shorter. Change the water every 2-3 days to prevent bacteria buildup. Stagnant water turns cloudy and stinks, which tells you it’s time for a refresh.

Set your jar in a spot with bright, indirect light—think east-facing window or under a grow light. Direct sun scorches the leaves, while too little light means weak, slow roots. You’ll know it’s right when the leaves stay vibrant green and the water stays clear between changes.

Rotate the jar a quarter turn daily so the stalk grows straight, not leaning toward the light. In 10-14 days, you’ll see tiny white roots sprouting from the submerged node. Once roots reach 2-3 inches, they’re ready to transplant—no soil needed yet if you’re keeping them in water long-term.

If you want to plant in soil, wait until roots are 3-4 inches long and well-branched. Fill a 6-inch pot with well-draining potting mix (lemon grass hates soggy roots). Dig a hole, gently remove the stalk from water, and tap out excess moisture before planting.

Press the soil around the stalk firmly to eliminate air pockets. Water lightly to settle the mix, then place the pot in partial shade for a week. This helps the plant adjust without shock. After that, move it to full sun and water when the top inch of soil feels dry. You’ll see new growth in 2-3 weeks—proof it’s thriving!

Tips & tricks for propagating lemon grass in water

Here's how to make your lemon grass propagation even faster and more successful.

Stalk Selection Matters: In Step 1, don't just grab any stalk—look for ones with a thick, firm base and at least 3-4 inches of growth. I've found that stalks with multiple nodes (those little bumps) root even faster because they have more potential root points. The thicker the stalk, the stronger your new plant will be.

Container Choice: While any clear container works, I recommend using a mason jar for stability and ease of cleaning. The wider mouth makes it simple to adjust water levels and trim stalks if needed. For faster root growth, use distilled or filtered water—tap water often contains chlorine or minerals that can slow root development.

Lighting Secret: In Step 3, bright indirect light is key, but here's a pro tip: if you don't have an ideal window spot, a grow light placed 6-12 inches above your jar works wonders. I keep mine on a timer for 12-14 hours per day to simulate natural daylight cycles. This consistency helps prevent leggy growth and encourages strong root development.

Root Growth Hack: To speed up the 10-14 day rooting process, add a pinch of cinnamon to the water when you change it every 2-3 days. Cinnamon has natural antifungal properties that keep the water fresh longer and may encourage faster root growth. Just use a tiny amount—about what would fit on a toothpick.

Frequently asked questions

Got questions about propagating lemon grass in water? You’re not alone! Here are some of the most common concerns—and their simple solutions—to help you grow lush, healthy stalks with ease.

How long does it take for lemon grass to root in water?

With the right conditions, lemon grass typically roots in 2–4 weeks. Watch for tiny white roots sprouting from the base of the stalk—once they’re 1–2 inches long, it’s ready to transplant! Patience is key, but avoid changing the water too often, as frequent disturbances can delay rooting.

Why isn’t my lemon grass growing roots in water?

If your stalks aren’t rooting, check these common culprits:

• Dirty or stagnant water: Replace every 3–5 days to prevent bacteria buildup.
• Low light: Place near a bright, indirect window (south or west-facing is ideal).
• Stalk too old: Use young, firm stalks (3–4 inches tall) for faster rooting.
• No bottom heat: Place the jar on a seedling mat or warm surface to mimic tropical conditions.