🌳 Willow
Salix spp.
Grows a foot a year, drinks like a fish, and will absolutely find your septic tank.
Sun
Full sun, 6+ hrs
Days to harvest
N/A — ornamental/shade; fast grower
Spacing
30+ feet from buildings, pipes, and septic — seriously
Soil pH
6.0–7.5, adaptable
How to grow
Plant in spring in the wettest spot you've got — pond edges, low swales, drainage areas. Willow roots aggressively seek water, so keep it far from plumbing, foundations, and septic systems (this is the voice of experience talking). True willows want consistent moisture, not drought.
Water & feeding
The thirstiest tree on this list — it will happily stand in seasonal flooding and sulks in dry soil.
Common problems
- Canker diseases on stressed trees
- Aphids and willow leaf beetles
- Root invasion of pipes and septic — plant far, far away
Harvest
Coppice or pollard in late winter for a flush of whippy new growth (great for basket weaving). Prune out crossing branches to keep the canopy airy.
Nerdy fact: Willow bark is nature's aspirin cabinet — salicin from willow bark led directly to the synthesis of aspirin, and it's also a rooting-hormone source gardeners use to strike cuttings.