In the gardener's world there are two mortal enemies – deer and disease. Or at least they are mine – if I ignore my parsnip-munching voles, Amazon-sized mosquitoes and steroidal slugs.
When my show stopping Heuchera (coral bells) were cut down in their prime by rust, a fungal infection, it was almost enough to make me hang up my trowel. Rust causes nasty raised, purple bumps on the undersides of the leaves which spreads rapidly and can quickly destroy the plant. Although not seen in drier parts of the country it is a major problem here in the Pacific Northwest.
Having tossed far too many of these pricey treasures into the yard waste (NEVER compost diseased plants) I asked Dan Heims, president of Terra Nova Nurseries, Inc. for some ideas on what I could do to save those that I have and ask about the new disease resistant hybrids his nursery is breeding.
As a breeding company, Terra Nova Nurseries, Inc. is the leading innovator for new Heuchera and Heucherella introductions. It can take seven years of breeding and another three of testing to have a breakthrough but that dedication is what ensures that their plants are strong and healthy.
So what exactly is rust and what can we do to prevent it?
It is a fungal disease that usually travels on the plant itself or is airborne. In our soggy Seattle climate we provide the perfect conditions for it to thrive so the key to control is managing the environment.
Dan's tips for healthy Heuchera
- Water in the early morning so foliage can dry
- Use drip irrigation rather than overhead sprinklers
- Space plants so as to allow for good air circulation
- Do not plant new Heuchera where diseased ones have been grown
- Remove diseased Heuchera immediately and dispose of in the yard waste (do not compost)
- The organic fungicide 'Serenade' may help prevent rust. (My personal experience has been that if you cut a mildly infected plant down hard and spray every two weeks (or as allowed on the label) until it is fully re-grown you have a reasonable chance of success; I may have been too hasty in disposing of a few).
Why are some Heuchera more susceptible than others?
The key word here is genetics or "it's all the parents fault". Now I did ask Dan to elaborate and share which species he was focusing on as showing the most promising disease resistant traits. His answer?
"I could tell you, but I'd have to kill you…Nothing personal… "
What he was able to tell me was that the breeders noticed that the lighter colored Heuchera were particularly susceptible, so they were selecting for thicker leaves. They were also committed to evaluating potential introductions under multiple conditions over many years and anything that showed signs of rust was eliminated. In other words he wasn't giving much away but that's OK, especially when you read about some of these success stories.
Breeder's top 5 (or 6, or 10)
Spellbound – you've heard me salivate over this beauty before. Shimmery shades of purple and silver on impossibly oversized leaves. Mine looks as magical now as it did in fall and has made a loose mound approx. 18" across. Fabulous in my orange container!
Blondie – this one is on my wish list for sure. Part of the 'Little Cutie' series, Blondie is just 8" wide but is a flowering powerhouse pushing out oodles of creamy-yellow spikes. Foliage color is in the caramel family. A good choice for containers
Sugar Berry – from hot raspberry to deepest blackberry, this one is positively delicious. Also part of the Little Cutie series this tops out at 6" tall and 10" wide with short, fat spikes of white flowers
Fireworks – ruffled bronze foliage on a mid-sized plant with plenty of soft colored flowers
Mahogany – this promises to be a good alternative to my beloved 'Peach Flambé' which succumbed to both deer AND disease last year! The foliage looks like burnished copper-colored leather and transitions through shades of red and orange as the season progresses. I'd love to see this with some bright lime green
Paris – another one that is high on my wish list, I love the silver veining on this green foliage and those hot pink flowers are just plain FUN. A mid-sized, compact plant at 14" wide.
All are hardy in zones 4-9, evergreen and do best if allowed to dry slightly between watering. Hummingbirds love them!
Where can we buy them?
What can we look forward to in the future?
Terra Nova Nurseries, Inc. is breeding some fabulous new Heucherella (foamy bells) which are rust resistant (yes you did read that correctly; all Heucherella are rust resistant for reasons which they undoubtedly know but will once again put my life in jeopardy if I ask) as well as continuing their Heuchera breeding program selecting plants which are healthy, have great foliage color and are vigorous.
They also have an exciting collection of heat-tolerant Heuchera , seeking out those with H. villosa in their parentage (apparently I was allowed to know that tidbit without death threats). Look for those with Southern sounding names as a clue e.g. Midnight Bayou, Southern Comfort and Georgia Peach.
Be sure to check out their website at www.terranovanurseries.com to get more tips and ideas as well as to drool over their luscious photographs.
And of course you are invited to 'like' their Facebook page
In the absence of a LOVE button, like will have to do.
My sincere thanks to Dan Heims (aka Mr. Heuchera) and the Terra Nova Breeding Team for finding time to answer my barrage of questions. Dan refers to himself as the 'man on the road' – I mainly see him at airports.
All photos courtesy of Terra Nova Nurseries, Inc. except where noted
UPDATE: there are some fabulous combination ideas using various Heuchera in book my books Fine Foliage (St. Lynn's Press, 2013) and Gardening with Foliage First (Timber Press, 2017). In addition Dan Heims wrote a helpful table called Heuchera Hot List in Gardening with Foliage First, giving recommendations to help readers substitute varieties as needed to suit their climate. (These affiliate links will save YOU money and earn me a few pennies towards my next Heuchera!)