Both work well, so the arum lily pots or ground question really comes down to your climate and how wet your soil stays. The choice is about control. A pot lets you move and protect the plant, while open ground lets it settle into one spot and form a big permanent clump over the years.
Think about it as a trade between freedom and roots. Arum lily container growing keeps the plant portable. You can chase the sun, drag the pot under cover in a frost, or carry it indoors for winter. Plant it in the ground and you give up that mobility. But the roots get all the room they want to spread, and a settled clump tends to bloom harder each year.
The plant loves constantly moist, rich soil and even tolerates standing water at the edge of a pond. That single fact drives the whole decision. Ground that stays damp on its own rarely lets the roots dry out, so a wet spot in your garden does the watering for you. A pot dries out far faster. That means more work in summer, but tighter control the rest of the year.
This is where most growers trip up. They treat an arum lily like a normal pot plant and water it once a week. In hot weather a container can need a soak every single day. The compost should feel damp to the touch at all times, not just moist on the surface. Stand the pot in a shallow tray of water during a heatwave and the plant will shrug off the heat with no trouble at all.
Size matters too. An arum lily reaches 2 to 3 ft (0.6 to 1 m) tall, so it needs a fair amount of space either way. In the ground it can keep widening into a thick stand of leaves and white blooms. In a pot it stays neater, and you can split it when the container fills up. A roomy pot of at least 12 inches (30 cm) across gives the roots a couple of good years before they need dividing.
- Move the plant to chase sun or dodge frost.
- Lift and store the whole pot over a cold winter.
- Control moisture in the compost day to day.
- Needs watering far more often in hot, dry weather.
- Roots get plenty of room to spread.
- Damp soil rarely lets the plant dry out.
- Forms a large, permanent clump over the years.
- Stays tied to one spot you cannot change.
Climate is the deciding factor for most gardeners. The plant is happy outdoors year-round in USDA zones 8 to 10. Drop below that range and frost can kill the roots, so pots win. When the plant lives in a container, you lift it and store it somewhere sheltered with almost no effort. Growing arum lily in pots is the simple way to overwinter it where the ground freezes hard. Try to dig a frozen clump out of cold open ground and you risk snapping the roots, which sets the plant back a full season.
In a cold zone, move the whole pot into a frost-free shed or garage before the first hard frost. Cut watering right back while the plant rests, then bring it back into the light in spring as new growth starts.
So here is the call. Pick pots if you live somewhere cold or dry, because you get easy overwintering and full control of moisture. Pick moist ground if your climate is mild and wet, since the plant will reward you with a fat, lasting clump that mostly looks after itself. Whatever you choose, never let container compost dry out in summer. A thirsty arum lily droops fast, and bone-dry roots are the quickest way to lose one.
Read the full article: Arum Lily: Complete Care and Safety Guide
