Planting Ismene bulbs

Ismene or Hymenocallis?

Hymenocallis is the botanical genus name that encompasses several species of bulbous plants primarily native to South America, Central America, and the Caribbean. These plants are often called “spider lilies” due to the shape of their flowers, which feature long, thread-like petals resembling spider legs.

The name Ismene refers to a specific hybrid resulting from the crossbreeding of different Hymenocallis species, namely Ismene x festalis. In other words, an Ismene is a Hymenocallis, but not all Hymenocallis are Ismenes.

The flowering of Ismene x festalis

When to plant Hymenocallis or spider lilies?

Ismene, or spider lilies, are typically planted in spring when all risk of frost has passed. The ideal period is between April and May, once the soil has warmed sufficiently. This allows them to establish properly before their summer flowering, which usually occurs in June or July.

Where to plant the spider lily?

Ismene, or spider lilies, should be planted in a location with sun to partial shade, so they can enjoy the light while being protected from the hottest hours of the day.

They prefer well-drained, light soil rich in organic matter, as excessive moisture could cause the bulbs to rot. If the soil is too heavy, it is advisable to lighten it with compost.

These plants thrive in warmth and should be placed in a sheltered spot away from wind. In pots, they also grow well, with the option to bring them indoors during winter in colder regions.

Ismene bulbs

How to plant the spider lily?

In the ground (especially for areas south of the Loire and the Atlantic coast)

• Loosen the soil and add compost to enrich it. Ensure good drainage, as bulbs dislike waterlogged conditions.
• Plant the bulbs at a depth of around 10 to 12 cm, with the pointed end facing upwards. Space them 20 to 25 cm apart to allow for proper growth.
• After planting, water moderately to help the bulbs establish. Maintain consistent moisture while avoiding overwatering.
• In regions with harsh winters, it may be necessary to dig up the bulbs in autumn and store them frost-free for replanting the following spring.

Pascal’s top tip: in the ground, a mulch can help protect bulbs from cold if you don’t wish to dig them up before winter. Mulching also helps retain moisture during warmer months.

In pots

• Choosing the pot: use a container at least 30 cm in diameter with drainage holes to prevent waterlogging.
• Preparing the substrate: fill the pot with a light potting mix enriched with compost.
• Planting the bulbs: place bulbs at 10 to 12 cm deep, pointed end up, spacing them 15 to 20 cm apart if planting multiple in the same pot.
• Positioning: place the pot in a sunny to partially shaded spot.
• Watering: water moderately after planting, then regularly during the growing season, allowing the surface to dry slightly between waterings. Avoid waterlogging.
• Overwintering: in cold regions, move pots indoors (to a cool, dry place) before the first frosts to protect the bulbs.

Note: in containers, the substrate depletes quickly. During active growth (spring and summer), a potassium-rich fertiliser (such as a flowering plant fertiliser) can promote better blooms. Apply fertiliser every two weeks or so.

Spider Lily Care

After flowering, the leaves of spider lilies turn yellow and wither. This is normal, as the plant then enters a dormant period. It’s important to reduce watering at this stage and not to cut the leaves until they are completely dry, as they still nourish the bulb.

If you wish to propagate spider lilies, remember to divide the bulbs every 3 to 4 years. This helps maintain vigorous plants and produce new specimens.