Pacific Plug & Liner is a great stop along the California Spring Trials tour to find a wide selection of plants from many different vendors, many of which are new introductions. One of the highlights at our stop is the comparison trial we have each year. We like to focus on genera with new breeding developments and an overabundance of choices for the grower. After Spring Trials, Pacific Plug & Liner is already thinking of what the following year’s trial will be, taking input from growers and breeders alike. Ipomoea, lavender, dianthus and lobelia have been trialed in the past and we thought what better genera to compare this year than heuchera. The breeding in heuchera has really taken off recently leaving growers with so many varieties to choose from it makes their heads spin!
The heuchera in this year’s comparison trial come from multiple breeders and were propagated in a variety of ways. Like all past comparison trials, this year’s varieties were grown side by side in exactly the same way. If we needed to move the plants to get more foliage development we moved the whole group; if we sprayed, we sprayed them all. No one plant got special treatment, so what was seen was how each variety grew in comparison to the others in the trial with the conditions we gave them.
With more than 100 varieties in the trial it is impossible to list them all here so I have only listed the series that were shown. For a complete list of the trial go to: http://ppandl.net/files/ppl//Availability/HeucheraComparisonTrialVarieti... 
Ball/Darwin: Big Top Series, Carnival Series
Danziger: Kira Series
Terra Nova Nurseries: City Series, Crisp Series, Little Cutie Series, Marmalade Series, Soda Series
In 2012, the trial was planted week 39 in an outside growing location in Watsonville, Calif. In week 49, the trial was moved to a non-heated covered hoop house to keep the crop out of the rainy days we get in the winter. Six weeks before the event, the trial was moved inside the greenhouse to develop more foliage
Culture. Plants were cold-grown and bulked for 21 weeks. They were later moved and grown warm to force foliage flush for Spring Trials. Higher growing temperatures did cause some stretch and floppiness on some, but not all, varieties. This was especially prominent on more vigorous varieties such as ‘Delta Dawn’ and ‘Southern Comfort’.
Transplant. Liners were propagated from seed, cutting and tissue culture and were transplanted in week 39 of 2012.
Environment. Plants were potted and grown outside in Watsonville, Calif., to allow for bulking. Watsonville temperatures averaged in the low 60s as a high and in the upper 30s to low 40s as a low during the months the trial was outside. In week 49, the trial was moved into a protected unheated structure to protect foliage from the cold morning fog and drizzle common in Watsonville at that time of year. In week 8, the trial was moved again to a warmer location inside the greenhouse to promote further foliage growth.
Pinching. Foliage was not pinched. Only dead foliage was removed; flowers were removed as they developed so foliage growth was not inhibited.
Growth regulators. No chemical growth regulators were applied to plants.
When we start a comparative trial, we hope to see some distinct winners and losers. Our heuchera trial was gigantic and from afar many varieties looked the same, especially the purple foliaged varieties. When viewed more closely, the differences became more apparent, such as plant habits, leaf texture and flower habit. Again, keep in mind, all plants were treated equally in this trial and we did not pinch the foliage or apply any growth regulators.
Of course everyone wants to hear what the favorites were; this is s a hard call to make with so many great cultivars out there.
Series. A series should be a well-matched group of plants in a range of colors, but with similar habits and growth characteristics. One thing I have noticed when working with many plant series is the lack of uniformity, whether it be growth habit, size or bloom time. The heuchera series trialed all showed nice uniformity. While all the series shown were very well-matched, I did have my favorite, which was the Marmalade series, for the wide range of color — from lime green to deep purple — and for their basal branching and overall vigor.
Best of show. In July 2013, I went through the trials again for one last assessment before we ended the trial. In May 2013, all varieties were trimmed back and then moved to a location outside that receives full sun. I decided to separate varieties based on color of foliage and then do an assessment of each of these color groups and came up with a top three for each.
Silver Purple: ‘Silver Scrolls’, ‘Fandango’, ‘Hollywood’
Purple Veil: ‘Shanghai’, ‘Frost’, ‘Plum Royale’
Purple: ‘Berry Marmalade’, ‘Melting Fire’, ‘Midnight Bayou’
Red: ‘Fire Alarm’, ‘Paprika’, ‘Mahogany’
Caramel: ‘Ginger Peach’, ‘Peach Crisp’, ‘Marmalade’
Lime: ‘Miracle’, ‘Lime Marmalade’, ‘Circus’
Green: ‘Hercules’, ‘Apple Crisp’, ‘Paris’
My selections are based on overall appearance and growth habit.
With more than 100 varieties trialed one might think, “How can you pick just one for best of show?” This is not an easy task but there was one variety that wowed me throughout the entire trial process and this was ‘Fire Alarm’. A new variety from TerraNova Nurseries, ‘Fire Alarm’ is one of the few true red foliaged varieties on the market today and it is certainly the brightest. ‘Fire Alarm’ was my top pick from the beginning and proved the test of time. Every time I looked at the trial I would always spot ‘Fire Alarm’ as a favorite, no matter the time of year and no matter if the trial was moved and reshuffled. The picture on page 32 was taken in July of 2013 and is of the same pot of ‘Fire Alarm’ that was displayed in April 2013.
Opportunities Going Forward
While one may think the heuchera world has become saturated, there is still room for improvement. I believe the greatest improvements can be made in the following areas:
• Providing more heuchera as a cutting input vs a tissue culture input so the price for growers becomes more affordable.
• Breeding for bright colors, especially the red color of ‘Fire Alarm’. I was told by heuchera experts at Terra Nova that this is a recessive gene so to express itself there must be a double recessive, which is why there are very few true red heucheras on the market today.
• Improved heat and sun tolerance for the lighter foliaged varieties.
Pacific Plug & Liner is always interested in feedback on its trials, and we are eager to hear what you would like to see in future comparison trials. For the 2014 Comparison Trials we will be featuring gaillardia. If you are interested in having your varieties represented please contact us.
One of the highlights of California Spring Trials each year is pacific plug & liner’s comparison trials. Find out how various heuchera varieties performed this year.