Thursday, August 27, 2009
Cutleaf Coneflower - Rudbeckia laciniata
Cutleaf coneflower (Rudbeckia laciniata) is one of the most unique of Florida's black-eyed susans. While it is found naturally in only 6 Florida counties (all in north Florida), it is found in nearly every state in the lower 48 and in nearly every province of Canada, except the extreme north. Despite its greatly restricted range in Florida, we have had good success growing it in our Pinellas County landscape here at Hawthorn Hill and it seems to be much more adaptable than might be otherwise indicated.
Cutleaf coneflower is native to moist sites and is not especially adaptable to drier conditions in Florida. If given sufficient soil moisture, it can be grown in full sun to partly sunny areas with good results. This species is rather robust. Individual plants may grow as much as 4 feet wide and their flower stalks may reach 4-5 feet in height.
Flowering occurs in summer to very early fall; generally from mid-August to September. The flowers are unique among Florida black-eyed susans as the centers are green instead of dark brown. The large blooms with their long, bright-yellow ray petals and the green disc flowers put on a spectacular show that lends real interest to any wildflower planting.
Cutleaf coneflower is a perennial. It spends its winter as a basal rosette of large rich-green leaves (in areas where severe freezes are uncommon) that look something like an extremely large version of Italian parsley. As new growth is added in the spring, these basal leaves are extremely attractive. We grow this species almost as much for its foliage and the interest this adds to our plantings as we do for the wonderful summer flowers.
Use this plant in mass for full effect. Because it is large, plant individuals at least 3 feet apart and somewhere in the center of your overall planting area. Let it go to seed and then prune the old flower heads so that the basal leaves once again become a focal point.
Well-established specimens in moist soil are reputed to sucker in other parts of its range. We have not seen that yet in our plantings and it may be that our conditions, outside of its natural range, limit this trait. We have grown cutleaf coneflower at Hawthorn Hill for several years and find it extremely easy to propagate from untreated seed. this is one species we nearly always have available and we encourage you to give it a try - if you have a site with ample moisture.