Grow and Care for Cardiocrinum

Grow Cardiocrinum in part shade and soil that stays moist but drains. Giant Himalayan lily is the shop name. It is not a true lily, and it is not a crinum or a daylily.

Give it part shade, moist woodland soil, and shelter from wind

Cardiocrinum is a woodland bulb with huge heart-shaped leaves and a tall raceme of fragrant white trumpets. Give it part shade and soil that stays moist but drains, because hot sun burns the leaves and standing water rots the bulb. [1] It wants a sheltered spot, the way it grows in mountain woods, with a spring mulch of leaf mould or compost so the soil stays cool and damp. [2] Giant Himalayan lily is Cardiocrinum giganteum.

Plant the bulb with the nose just showing

Buy a dormant nursery bulb and plant it as soon as you have it. Set the nose — the pointed tip — just at the soil surface, not deep the way you plant a true lily. Fall is a good window; spring works if the ground is workable and not frozen. [3]

1. Choose part shade and deep soil you have enriched with leaf mould or compost.
2. Plant in fall if you can, or in spring as soon as the ground is workable.
3. Set the bulb so the nose sits just at the soil surface, and give it about 2 feet of room so offsets can form.
4. Water in once, then keep the soil damp while it settles. Do not park the bulb in a holding pot if you can plant it in the ground that day.
5. Label the spot. The leaves vanish after the stem dies, and a later dig can spear the offsets.

After it flowers, the old bulb dies — keep the offsets

The flowering bulb dies after the trumpets fade. That is normal. Small offset bulbs form around the old one, and those keep the clump going. They usually take four or five years to bloom. Leave the leaves until they yellow so the offsets can store food. [4]

1. Let the stem and leaves die back after bloom. Cut the seed pods off if you want the plant to put more energy into offsets.
2. If the clump is crowded, lift it after the top growth has died, and separate the offsets by hand.
3. Discard the spent flowering bulb. Replant the offsets at once, with each nose just at the soil surface, and water them in.
4. Keep the soil moist the next growing season. Do not store the offsets dry.

Seed takes years — offsets flower sooner

Seed is the slow path. Fresh seed often needs a warm spell and then cold before it sprouts, and a plant from seed can take about seven years to bloom. Offsets from a flowered bulb reach size sooner.

1. Sow ripe seed in late fall, or in spring, in a deep pot of seed mix.
2. Cover the seed lightly. Keep the pot cool, shaded, and just damp. Germination may take a year or two.
3. Grow the seedlings on without letting the mix dry. Plant a strong young bulb into the woodland bed while it is dormant.

Not a true lily — and not crinum or daylily

Shop tags still say giant lily, and older lists still say Lilium giganteum. True lilies have narrower leaves that clasp the stem, and you plant those bulbs deep. Cardiocrinum has heart-shaped leaves on leaf stalks, and the bulb sits at the surface. See How to Grow Lilies. Crinum is a different bulb with strap leaves and a wetter, often warmer bed — see How to Grow Crinum. Daylilies are Hemerocallis, with grassy fans that bloom a day at a time — see How to Grow Daylilies. Confirm Cardiocrinum on the Latin. The leaves can look like a hosta in spring, but this is a lily-family bulb, not a hosta clump.

Set the bulb in part shade with the nose at the soil surface, keep the soil moist, and leave the offsets in place after the flowering stem dies.