Intergeneric crosses, oddities some botanists say are an impossibility, have made serious inroads in the perennial world.
New heucherella and digiplexis introductions are becoming more common. Walters Gardens introduced heucherella ‘Pink Fizz’ and digiplexis ‘Berry Canary’ in 2014, while digiplexis ‘Illumination Apricot’ will join the Sunset Western Garden Collection in 2015.
Terra Nova Nurseries offers the heucherella Falls series, which president Dan Heims says opens a whole new marketplace of flowering groundcovers in many foliage colors, as well as new container and hanging basket options never before enjoyed by the public.
Tony Avent, owner of Plant Delights Nursery says to watch for more fern hybrids coming out with good heat tolerance, as well as crosses of agaves with tuberosas and agaves with hostas.
Echibeckia is another highly promoted, purported cross, but it appears to be nothing more than a normal Rudbeckia hirta, Avent says.
“We have to be careful with intergeneric crosses and make sure they are truly what they say they are,” he says. “If we don’t, we will lose credibility with consumers, something our industry can’t afford.”
Digiplexis is a case in point. Karl Batschke, global perennial product manager at Darwin Perennials, says digiplexis was first thought to be a cross between Digitalis purpurea and Isoplexis canariensis.
“After the cross was made, taxonomists came out and said I. canariensis was actually a digitalis. What we thought was an intergeneric hybrid was really an interspecific hybrid, so now we have moved to using the taxonomically correct genus of digitalis for our Foxlight series,” Batschke says.
All that being said, intergeneric crosses have the potential to make big contributions to plant breeding. As Melanie Neff, new products manager at Aris Green Leaf Plants says, it’s exciting to combine features of multiple genera to get truly unique varieties that help solve problems like adding cold hardiness and disease resistance.