Scilla peruviana, also known as Portuguese squill, is a spring-blooming bulb with striking, lavender-blue flowers. The flowerheads can be the size of a softball, with star-like florets that open gradually over a period of 3 weeks or more. The plants have long, strappy leaves similar to a hyacinth, and grow 12-20” tall, with flowers on 6-12” stems.
This bulb grows best in warm, arid climates that are similar to the Western Mediterranean region where the plants grow wild. When the bulbs get enough moisture, they retain their foliage almost year-round. In areas with dry summers, the bulbs go dormant shortly after they bloom and sprout new leaves in the fall. Scilla peruviana’s foliage tolerates temperatures as low as 28°F. The bulbs are considered winter hardy in zones 7-10 (zone 7 with winter protection).
Scilla peruviana should be grown in well-drained soil that has a sandy or gritty texture. The bulbs will not tolerate soil that is dense and heavy, overly moist or too rich. Full sun is best for flowering, but the plants will also grow in partial shade.
Bloom time is late spring to early summer. The plants need moisture before, during and right after flowering. During the summer months, the soil should stay as dry as possible. The bulbs usually lose their foliage for a few months during the summer and then sprout new foliage in the fall. These leaves will persist through winter and spring as long as air temperatures don’t drop much below freezing.
In the wild, scilla peruviana bulbs grow at or just above the soil surface. To mimic these conditions, plant the bulbs shallowly so the very tip of the bulb is right at the soil surface. The bulbs should be spaced about 8 to 10” apart.
In colder areas, Scilla peruviana grows best in containers. Plant the bulbs shallowly and fertilize before and immediately after flowering. Once the foliage fades, stop watering and put the pot in a protected area where the soil will stay relatively dry. Bring the container indoors in the fall to protect the bulbs from cold.
As with other bulbs, it’s best to remove the spent flowers after they fade. Cut the stems close to the base of the plant. Let the foliage continue growing. It will usually yellow and fade away by midsummer.
Over time, Scilla peruviana bulbs can multiply and form large clumps. If flowering gradually decreases, dig and divide the bulbs in early summer to give them more room.