Coreopsis verticillata ‘Zagreb’
Description & Overview
Zagreb Coreopsis is a compact, clump forming plant with airy, thread-like bright green foliage. Daisy-like golden-yellow flowers are borne above the foliage throughout the summer. This selection is longer-lived than ‘Moonbeam’, making it a fine replacement that has a place in any garden. An excellent starter plant for those wanting easy to grow perennials.
Zagreb Coreopsis is great as a soft border or mass in the garden. Planted at 18” spacing on-center, the plants will fill together within a year. At wider spacing, the plants form individual mounds that remain distinct for several years. At a height of only 18”, Zagreb Coreopsis won’t compete with taller, coarser perennials like Hummelo Lambs Ear or Magnus Purple Coneflower for your attention. It tolerates heat, humidity, drought, rocky and dry soils, and is easily grown in full-sun beds. Zagreb Coreopsis is great in tough urban sites as long as the soil has decent drainage.
The flowers of Zagreb Coreopsis are great in pollinator gardens for butterflies and bees. In fall, the dried seed heads are a food source for birds (if left on the plant). Deer and rabbits seem to ignore it as a food source.
Zagreb Coreopsis is a great, low-maintenance plant for those getting started in gardening. To encourage additional blooms, you can deadhead the plants with a hedge trimmer after the blooms are finished. This can also prevent reseeding if you want the plant to stay contained. It will eventually spread via rhizomes and can be divided every 3-5 years if you want to contain its growth.
Although a tough plant, Zagreb Coreopsis can become sprawling and unkempt if grown in fertile soils with consistent moisture. In sites with poor drainage, crown rot can become a problem. Occasional slug and snail damage may be observed, but we don’t believe it’s worth controlling unless you have other susceptible plants being damaged (like Hostas).
Powdery mildew, botrytis blight, fungal spots, and aster yellows have been observed on Zagreb Coreopsis in rare occasions, but these diseases happen so infrequently it’s hardly worth mentioning.
Zagreb Coreopsis is a compact selection of Threadleaf Coreopsis (Coreopsis verticillata) that is found in open woodlands, forest edges, and savannahs of the east coast. The species has been a popular garden plant for over 100 years, and for good reason. It’s easy to grow, divide, and naturalize, and it’s both long-blooming and long-lived. While the occasional plant may die, rarely will you lose an entire mass-unless you’ve had a particularly wet winter in the planting location.
Although Threadleaf Coreopsis is a American native, ‘Zagreb’ was developed by the Department of Ornamental Plants and Landscape Architecture at the University of – drumroll please – Zagreb! In Zagreb, Croatia, of course. It was selected in 1997 for its long bloom period and more compact habit, maturing to less than half the height of the species. It is an improvement over ‘Moonbeam’ for its better bloom color, general toughness, and that it breaks dormancy earlier and enters dormancy later than ‘Moonbeam’.
Coreopsis is also known as Tickseed because its small seeds are said to resemble the size and shape of ticks. In fact, the genus name Coreopsis derives from the Greek words ‘koris’ (bug) and ‘opsis’ (appearance, optics). Don’t worry, though, the plant won’t give you Lyme Disease.
As Zagreb Coreopsis doesn’t play nice in moist, fertile soils, it’s best to pair it with other plants of similar site requirements. Montrose White Calamint, Butterflyweed, Hairy Wild Petunia, Pale Purple Coneflower, and Russian Sage are all great perennial combinations. St. John’s Wort, Ninebarks, and Smoketree would all be excellent contrasts to the lacey and airy texture of Zagreb Coreopsis.