Hydroponic Vietnamese Coriander: Growing Rau Ram from Cuttings

Hydroponic Vietnamese coriander is Persicaria odorata, also sold as rau ram, grown with its roots in a nutrient solution. The UC Master Gardeners of Santa Clara County say the easiest start is a bunch from an Asian grocery store in spring, with the stems rooted in water. That habit suits a water system.

The short answer

Root grocery store stems in a glass of water, then move them into net pots on a raft or bucket with an aerated nutrient solution. Give full sun to partial shade and plenty of water, then pick young leaves about two months after planting.

Can Vietnamese coriander grow in a hydroponic system?

The UC Master Gardeners list it as a perennial that prefers moist to wet soil and full sun to partial shade. It grows 6 to 18 inches high and wide, and they note it can be grown as an indoor plant. A plant that likes wet roots and roots easily in water suits deep water culture. The UC Master Gardeners of Orange County say deep water culture relies on an air pump and air stone to aerate the solution. Compare root zone materials in hydroponic in different mediums.

Which hydroponic setup suits Vietnamese coriander?

A bucket or raft is simplest. The University of Minnesota Extension says net pots should be only partly submerged so roots get oxygen. It describes two ways to add air, a Kratky air gap above the water or an airstone joined by tubing to an outside pump. Virginia Cooperative Extension suggests checking EC and pH two to three times a week and gives a pH of 5.5 to 6.2 for most crops. Minnesota advises a growing area over 65°F. Routine upkeep is in caring for your hydroponic system.

How do you harvest Vietnamese coriander grown in water?

The UC Master Gardeners say to begin harvesting leaves about two months after planting in spring. Only the leaves are used in cooking, raw or cooked, in salads, rice dishes, soups and stews. Pick young tips. Space out new cuttings with growing schedule for your hydroponics.

Rau ram in hydroponics

Sources: UC Master Gardeners of Santa Clara County, University of Minnesota Extension, Virginia Cooperative Extension, UC Master Gardeners of Orange County.

How to: step by step

1. Buy a fresh bunch of rau ram in spring.
2. Stand the stems in a glass of clean water until roots show.
3. Move rooted stems into net pots on a raft or bucket lid.
4. Run an airstone or leave an air gap under the pots.
5. Check pH and EC two to three times a week.
6. Pick young leaves about two months after planting.

Troubleshooting

Stems that do not root: old stems, so start again with a fresh bunch.

Roots turn brown: still water. Add an airstone and lower the water line.

Leggy plants indoors: low light. Move them toward full sun or add a light. The hydro setup environment post covers room setup.

Kind Seed Co shares these notes for growers who cook with fresh herbs.

Sources

• Vietnamese coriander, UC Master Gardeners of Santa Clara County
• Small scale hydroponics, University of Minnesota Extension
• Hydroponic production of edible crops: deep water culture (DWC) systems (SPES 464), Virginia Cooperative Extension
• Hydroponics for the home gardener, UC Master Gardeners of Orange County