Crinum Planting Guide

Crinums are low maintenance, long lived and delightfully fragrant. Where happy, they’ll spread gently over time to form large colonies. (Don’t worry, they aren’t aggressive garden thugs.) While crinums typically take two to three years to develop into mature plants, they’ll reward your patience by performing their magic pretty much for the rest of your life. Not a bad deal for a price that's about that of a large pizza.

Choosing a Site

Crinums love the sun and bloom best when provided with lots of light. In the hottest parts of the country a bit of midday or late day shade helps avoid leaf edge burn. While one of the common names for these plants is “swamp lilies”, and some varieties will actually grow on a pond edge. However, the cultivars offered here are not ideally suited to sites with consistently wet soils.

Soil Prep

These crinums prefer average to moist, but not soggy, soil. A planting site with average garden soil or containers with commercial potting mix work well. Adding a slow release fertilizer when you plant or a dilute fertilizer monthly during active growth provides nutrients for potted crinums. When planted in the garden additional fertilizer not required.

When to Plant Crinums

Plant outdoors when frost danger has past. Once established, crinums can manage cold to about 10 degrees Fahrenheit. For extra protection against winter conditions, mulch plants in the fall with 3-4” of pine needles or bark mulch. Pull back the mulch in spring when you see the first new sprouts.

How to Plant Crinum Bulbs

When planting crinum bulbs, dig holes 6 inches deeper than your bulbs are tall. Refill the holes with enough loosened soil to raise the bulbs so that about half their necks remain uncovered. Tamp down soil and water well. The bulbs will begin to develop roots and sprouts within a few weeks.

During the Season

Crinums require little care during the growing season. Feel free to trim or snap off spent flowers to keep the plants looking their best. Water if there’s a period of 10+ days when rains don’t provide moisture. This is only necessary the first year.

After your crinums are established they’ll manage without supplemental watering. When your crinums have established into a nice clump, adding a balanced slow release fertilizer in mid spring and late summer is helpful, but not necessary. Do not feed in fall as the plants are moving into a low growth or dormancy period then.

At the Season’s End

For gardeners in zones 8-10 crinums are perennials, successfully overwintering outdoors. In zone 7, protected sites such as along a stone wall or brick house foundation with a southern exposure, offer an extra measure of safety. Where winter hardiness is questionable, mulch crinums with 3-4” of bark chips or pine needles to provide extra protection.

In colder climates, move your containers to a cool, but not freezing, location for overwintering. An unheated garage often works well. Allow the soil to dry for a week and then tip the pot on its side. This ensures that water won’t pool around the base of the bulb, causing rot. Allow the bulbs to rest until spring weather, including night temperatures, is warm enough to move the pots back outdoors. At that point, relocate and water well. Look for crinums sprout to appear shortly.

Insider Tips

  1. Size counts with crinums. Tiny bulbs may grow fine but will take many years to reach flowering size. See photo on this page for the size bulbs we ship. Our bulbs are 20-26+cm in circumference which translates to 9-10” around. This is the size of a medium to large pear. These bulbs typically begin flowering in year two or three and continue for generations.
  2. Good light is rewarded with more flowers. While plants may survive in shady sites, bloom quantity will be reduced.
  3. Crinum plants flower well when rootbound. Use this to your advantage when planting in containers by choosing a pot that’s 4-5” wider than your bulbs, rather than a huge container.
  4. Individual flowers are short lived. When one fades, snap it off. New buds will open up.
  5. Over time, crinums plants tend to multiply and become crowded. While they will survive without dividing, flowering is improved when plants have more space. Dig, separate and replant at the same soil level every 4-6 years or as needed. Enrich soil with compost to add nutrients.
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Success Snapshot

Light: Full sun to partial sun

Soil: Average

Depth: Plant leaving bulb neck exposed

Water: Average moisture

Uses: Containers, borders, foundations and walkways

Tip: Site to enjoy fragrance

GUIDE: Crinum Planting Guide

They Start Out Looking Like This: