Hydroponic Pickerelweed: Pontederia in Container Water Gardens
Hydroponic pickerelweed (Pontederia cordata) grows in a pot set under shallow water. It is a native marginal plant with heart shaped leaves and lavender blue flower spikes. A wide tub on a patio suits it well.
The short answer
Pot pickerelweed in heavy clay loam and set it in a tub under up to 12 inches of water. NC State lists full sun and notes it handles flooding up to 20 inches. Blue flower spikes open from summer through fall. It grows up to 4 feet.
What is pickerelweed?
NC State describes pickerelweed as a native perennial that grows up to 4 feet tall. Its rhizomes form colonies, and lavender blue flower spikes appear from summer through fall. It is hardy in USDA Zones 3 to 10.
It is a native marginal plant that grows in shallow fresh water.
How do you plant pickerelweed in a tub?
Illinois Extension covers container water gardens. Colorado State suggests heavy clay loam topped with gravel. NC State says pickerelweed does well in large containers or water gardens.
A wide tub holds the water and a pea gravel cap holds the soil in place, as Kansas State suggests.
How deep should the water be?
NC State says pickerelweed prefers fresh water up to 12 inches deep and tolerates flooding up to 20 inches. Water should sit above saturation but below the leaves. For winter, Kansas State suggests sinking it 12 inches below the waterline.
| Option | What it does | Source |
|---|---|---|
| Up to 12 inches | Preferred growing depth | Pontederia cordata (pickerelweed), NC State Extension Gardener Plant Toolbox |
| Up to 20 inches | Flooding it tolerates | Pontederia cordata (pickerelweed), NC State Extension Gardener Plant Toolbox |
| 12 inches in winter | Winter depth in a pond | Water Gardening: Plants for the Water Garden (MF2912), K-State Research and Extension |
How to: step by step
- Choose a wide tub that holds water.
- Pot the plant in heavy clay loam.
- Top the pot with a layer of pea gravel.
- Set the pot so water covers the crown but not the leaves.
- Place the tub in full sun.
- Divide the clump when it crowds the pot.
Troubleshooting
Few flowers: shade, so move to full sun.
Floating soil: light potting mix, so use heavy media.
Crowded pot: spreading rhizomes, so divide and repot.
Kind Seed Co shares these plant notes for growers of all kinds. For more on root media see hydroponic in different mediums. See pond water for cannabis and aquarium water for cannabis for related water notes. Read caring for your hydroponic system for system care.
Sources
- Pontederia cordata (pickerelweed), NC State Extension Gardener Plant Toolbox
- Planting the water garden container, University of Illinois Extension
- Water gardens: planting aquatic plants (PlantTalk 1026), Colorado State University Extension
- Water Gardening: Plants for the Water Garden (MF2912), K-State Research and Extension
FAQ
Is pickerelweed native?
Yes. NC State lists pickerelweed as native to North America.
Can pickerelweed stay outside in winter?
NC State lists it as hardy in USDA Zones 3 to 10. Kansas State suggests sinking it to 12 inches below the waterline in winter.
Do pollinators visit pickerelweed?
NC State notes that its flowers attract pollinators and that it is deer resistant.
How big does pickerelweed get?
NC State lists pickerelweed at up to 4 feet tall. Its rhizomes form colonies.
How deep should pickerelweed sit?
NC State says it prefers fresh water up to 12 inches deep and tolerates flooding up to 20 inches.
