This week the subject is Kerria, a later spring bloomer that sports yellow single or double blooms and thrives in shadier locations. Kerria is a much under-used one in the landscape. My grandmother had one and I have never used one in the landscape although with my aging and spreading oaks, it would be a good plant to consider.
Kerria is a decidous shrub with green stems that hold their color all year long. Like Forsythia, it can sprawl to heights of eight feet and 12 feet in width. Plant like moist, well-drained soil, but once established, can survive in the dry shade under the canopy of large trees. Kerria has relatively no pest problems. This plant does not require fertilizer to stimulate bloom - you will succeed in getting more green growth only. As with Forsythia, Kerria will "sucker" easily. These freebies can be dug up and replanted in other locations in the fall or winter.
Kerria looks good sprawled on vertical structures like wooden fences. It dresses up shrub borders and cottage gardens. It makes an excellent backdrop for azaleas, rhododendrons, smaller woodland flowers and understory trees.
As mentioned, Kerria comes in single-or double-bloom selections. Pleniflora has double flowers that are almost spherical. It is showier and taller than its parent species, but not as dense. Picta has leaves that are edged in white and brightens shady areas even when plant is not in bloom. Its flowers are single in bloom.