Extension News

Ask the ISU Extension Garden Experts: Siberian Squill, Peas and Creeping Phlox

Note to media editors: Got gardening questions? Call the Hortline at (515) 294-3108, Monday-Friday from 10 a.m. to noon and 1 to 4:30 p.m., or e-mail us at hortline@iastate.edu. For more gardening information, visit us at Yard and Garden Online, http://www.yardandgarden.extension.iastate.edu.


What is the identity of the small, blue-flowering plant that blooms in April?

The small, blue-flowering plant is probably Siberian squill (Scilla sibirica). Siberian squill is an early spring flowering bulb. Plants typically bloom in early to mid-April in Iowa. Bright blue flowers are produced on four- to six-inch-tall plants. Siberian squill is easy to grow and prefers partial shade. It’s most effective when planted in masses under trees and shrubs and along woodland edges. The flower spikes on ‘Spring Beauty’ (the most widely planted cultivar) are slightly larger than the species. Siberian squill multiplies rapidly. The foliage of Scilla sibirica dies back to the ground by early summer.

When should I plant peas?

Peas are a cool season crop. They should be planted as soon as the ground can be worked in spring. Suggested planting dates are late March/early April in southern Iowa, early to mid-April in central Iowa, and mid to late April in northern portions of the state. Sow seeds 1 to 1.5 inches deep and 2 inches apart.

What are suitable planting sites for creeping phlox?

The brightly colored flowers of moss phlox (Phlox subulata), oftentimes referred to as “creeping phlox,” are a common sight in many home landscapes in spring. Moss phlox forms dense, carpet-like mats. Plants are 4 to 6 inches tall. Its foliage is narrow, stiff, and needle-like in appearance. Flower colors include white, pink, red, blue and purple.

Excellent varieties include ‘Emerald Blue,’ ‘Emerald Pink,’ ‘Scarlet Flame’ (rose-pink) and ‘White Delight.’ Moss phlox is easy to grow. It performs best in sunny areas and well-drained soils. Shearing plants back after flowering promotes dense growth. Moss phlox is useful for edging beds and as a groundcover for sunny slopes. It also looks nice planted atop a wall or in rock gardens.


Contacts :

Richard Jauron, Horticulture, (515) 294-1871, rjauron@iastate.edu

Del Marks, Extension Communications and External Relations, (515) 294-9807, delmarks@iastate.edu