Growing Hydroponic Sweet Marjoram in Towers and DWC
The short answer
Hydroponic sweet marjoram is Origanum majorana, a soft leaved herb in the mint family with a milder, more delicate flavor than oregano. NC State Extension notes it wants full sun and good drainage and rots when its roots stay saturated. Grow it with roots partly in solution, bright light and frequent trims.
Does sweet marjoram grow well without soil?
Yes, with care at the roots. NC State Extension describes sweet marjoram as a subshrub about 2 feet tall that is grown as an annual north of zone 9. It needs drainage and rots when saturated. In water, that means roots should not sit fully submerged in still solution. The University of Minnesota Extension advises net pots that sit only partly in the solution, with an air stone to move oxygen.
Minnesota also notes that most herbs need at least 6 hours of direct sun, and that very rich conditions can reduce the oils that give herbs their flavor. Indoors, run a grow light and feed moderately.
Which system suits marjoram, towers or DWC?
Either works. Virginia Cooperative Extension lists culinary herbs among the crops grown in deep water culture. In DWC, aerate the solution and set cups so the upper roots stay in air. In a tower, the solution runs over the roots and drains away between cycles, which suits a herb that dislikes saturated roots. Pick the system you already run, and give plants room to reach about 2 feet. Read caring for your hydroponic system for upkeep across both.
How do you trim marjoram for full, leafy growth?
Snip stem tips all season. NC State advises cutting the plant back before it flowers and harvesting before bloom. Minnesota describes herb harvest as regular snipping through the season. Take a few inches from each stem above a pair of leaves so side shoots form. Dry extra stems by hanging them for 7 to 14 days, as Minnesota suggests for herbs.
Sweet marjoram growing basics
| Stage | What to do | Notes |
|---|---|---|
| Start | Sow seed or root cuttings | Start seed under lights 6 to 8 weeks ahead |
| Move | Net cups, roots partly in air | Rots when saturated |
| Light | Bright grow light | Most herbs need 6 hours of direct sun outdoors |
| Feed | Moderate rate | Rich conditions can reduce oils |
| Trim | Snip tips before flowers | Harvest before bloom |
Sources: NC State Extension, University of Minnesota Extension, Virginia Cooperative Extension.
How to: step by step
- Sow marjoram seed in plugs under lights, or root cuttings from a plant you already have.
- Feed a diluted solution once seedlings appear.
- Move plants into net cups in a tower or DWC system.
- Leave the upper roots in air and aerate the solution.
- Run a bright grow light on a timer.
- Snip stem tips often and cut back before flowers open.
Troubleshooting
Roots turn brown and soft: roots sit saturated. Lower the solution and add air.
Thin, weak flavor: the feed is too rich, so ease back.
Plants flower early: trimming is too light. Cut back before buds open.
A fragrant herb for any system
Sweet marjoram gives soft leaves for months with regular trimming. Plan sowings with growing schedule for your hydroponics and compare root media in hydroponic in different mediums. Kind Seed Co shares more hydroponic herb notes on the blog.
Sources
- Origanum majorana (sweet marjoram), NC State Extension Gardener Plant Toolbox
- Growing herbs in home gardens, University of Minnesota Extension
- Hydroponic production of edible crops: deep water culture (DWC) systems (SPES 464), Virginia Cooperative Extension
- Small scale hydroponics, University of Minnesota Extension
FAQ
Is sweet marjoram the same as oregano?
No. Sweet marjoram is Origanum majorana. NC State Extension notes it has a milder, more delicate flavor than perennial oregano, Origanum vulgare.
Can you grow marjoram from cuttings?
Yes. NC State Extension lists division, leaf cuttings and seed as ways to propagate sweet marjoram. Root cuttings in plugs, then move them into net cups.
How often can you harvest marjoram?
Snip stem tips through the season whenever there is new growth. Cut the plant back before it flowers to bring on fresh leaves.
Does marjoram like warm water?
The sources here give no water temperature for marjoram. What they stress is drainage, since it rots when saturated, so aerate the solution and leave the upper roots in air.
How do you dry marjoram?
Hang small bunches for 7 to 14 days, or use a dehydrator at 95 to 115°F, as University of Minnesota Extension suggests for herbs.
