September 2015 Big Grower, Culture, Grower News, Plant Health, Production, Variety Info

Comparing Coreopsis By April Herring-Murray

At Pacific Plug & Liner we continually strive to be one of the must-see stops along the Spring Trials circuit. Our goal is to display a wide selection of new introductions, not only our own but many from different vendors, including Cohen, Cultivaris, Hishtil, Jaldety, and the Southern Living and Sunset Western Garden Collections, perennials being a major portion of genetics shown.

In keeping with tradition, and the reason Spring Trials, or what used to be called Pack Trials, was started, Pacific Plug & Liner will grow and display a true comparison trial each year. The trial focuses on a genera or a group of plants with new breeding developments and an overabundance of choices for the grower. Dianthus, heuchera and gaillardia have been trialed in the past. We chose coreopsis this year because we are seeing more and more varieties hit the market and we wanted to see for ourselves what the real differences were. With all the new breeding being done, it was interesting to see the direction this group of plants is moving toward.

The coreopsis in this year's comparison trial come from multiple breeders and were propagated from both seed and cuttings. All plants in this year's comparison trial like all other comparison trials in the past were grown side by side in exactly the same way. If we needed to move the plants for any reason we moved the whole group; if we sprayed, we sprayed them all. No one plant got special treatment, so what was seen is how each variety grew in comparison to the others in the trial with the conditions we gave them.

With around 70 varieties in the trial it is impossible to list them all here so I have only listed the highlights of what was shown. For a complete listing of the trial including blood line, patent and royalty information go to: www.ppandl.net/files/ ppl//Availability/CorepsisComparisonTrial.pdf

Trialed Varieties

Varieties from Seed
Kieft Seed: 'Early Sunrise', 'Rising Sun', 'Sun U'p, 'Sunfire'

Varieties from Cutting
Darwin: 'Sunny Day'
Blooms of Bressingham: Limerock series Conard-Pyle: Ka-Pow series
Danziger: Highland, Prairie and Solanna series Dümmen Orange: Leading Lady series
Itsaul Plants: Cruizin series
Sunny Border: Coloropsis, Big Bang, and Permathread series
Terra Nova Nurseries: Hardy, Hardy Jewel and Verticillata collections, and Lemonade and Pie series

The Setup

In 2014, we sourced all of the varieties we could find for this genus, and depending on input availability, the rooted liners were planted in weeks 45-50, one liner per 2.5 quart. All plants that were reviewed for this article were field grown in Watsonville, California. To have blooming plants for Spring Trials, part of the trial was grown under long days using incandescent lights and slightly warmer temperatures under a covered hoop house, the other half of the trial was left growing under natural field conditions. While the artificial lighting helped more varieties bloom for the show, it also caused stretching for many of the perennial varieties.

Environment. Plants were potted and grown outside in Watsonville to allow for bulking during the winter months. Watsonville averaged in the low 60s as a high and in the upper 30s to low 40s as a low during the winter months. During the spring, we moved into mid-60s as a high and mid-40s as a low. For summer observations, we bumped the 2.5-quart crops to a 7-gallon tub in week 26. We averaged low 70s as a high and low 50s as a low. I know, not fair!

Pinching. We did not pinch at any time.

Growth Regulators. Growth regulators were not used throughout the trial.

Results

When we start a comparative trial, we hope to see some distinctive winners and losers. Our coreopsis trial was tough because there were so many different types being trialed. We had pure annual types, and on the perennial side of things we had long-blooming grandiflora types, pure verticillata types and hybrids that could have up to eight species bred into them! When viewed over the course of time, differences became apparent, mostly in plant habits, flower colors, foliage type and bloom times. Because many of the perennial varieties did not even attempt to bloom by week 15, we continued the trial into late July. Since we do not have a trial garden on site we potted everything into 7-gallon tub containers so that we could get more of a garden performance trial. A mirror of this trial was also planted at Smith Gardens in Marysville, Washington, in their trial garden. Similar observations were made there as at our Watsonville site.

Annual Types.These types may not be hardy, but they are great for early season color. We had no issues getting Coloropsis, Highland and Prairie into bloom for the week 15 spring trials event. Not only are they nice standalones but would make great mixed container components.

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 coreopsis series trialed were not the exception but I have to say they were the most well-matched group of plants I have trialed to date. There were just a few series that were not consistent in height. Another observation I made was some breeders do denote if the plants are in a collection or a series so one should be sure and note this when deciding what plants to grow. An example is the Hardy Jewel Collection from Terra Nova; these are similar in that they are hardy with thread-like foliage and come in jewel tones but they are not matched perfectly, Citrine being much shorter than the others. When booking plants, read all the information supplied by the breeder so you are not surprised.

A Different Presentation. Along the way I saw some very well-matched series or well-matched plants that are not in a series, and it got me to thinking we should trial some of these for trio possibilities, planting three colors into the same pot. My suggestions for trial are the Limerock and Lemonade series. For larger containers with big impact, try the Big Bang series picking from Full Moon, Mercury Rising, Polaris and Redshift as they are the most closely matched in the series. From Terra Nova, how about a trio of 'Autumn Blush', 'Cran- berry Ice' and 'Desert Coral' for a medium-sized thread leaf combo. Or for a larger mix try 'MC Flower of Hope' mixed with 'Cruizin' Broad Street' and 'Cruizin' Route 66' from Itsaul Plants. I am sure there are many other possibilities, but these are the ones that stood out to me as really good matches in a wide range of flower colors.

Best of Show

In July of 2015, I went through the trials again for one last assessment before we ended the trial.

Best foliage. Yes, a strange category for coreopsis but I had to include this just for the Lemonade series! The foliage is threadleaf and bright yellow and a super upright habit. Even after being in a pot for nearly 40 weeks, and moved all around the facility, 'Impe- rial Sun' still did not break or crack open!

Best up and comer. Ka-Pow Series from Star Roses. This new series was bred by Darrell Probst so it is similar in appearance to the Big Bang series, only way more compact. I noticed the foliage was very stiff and the plants did not get overly tall when we tried to force them into bloom for the Spring Trials event. We were successful in forcing this series into bloom, so this series could be brought to market a little sooner in the spring season with a little help from lights. Flowers are huge and in your face, perfect name for the series, Ka-Pow!

With nearly 70 varieties trialed one might think, "How so even when these beauties are not blooming they are still showy. In fact we used them in a number of places during our spring trials event for a foliage accent in mixed containers.

Best early bloomer. 'Solanna Golden Sphere' from Danziger Flower Farm. The grandiflora blood is the reason this perennial selection starts to bloom so early, we had no issues getting it into full bloom for our week 15 show. The pom pom double flowers really screamed for attention and the compact habit made this one a real winner. It was another selection that worked great in mixed containers.

Best late bloomer. 'Firefly' from Terra Nova. This verticillata selection might be late to the party but really makes a grand entrance come end of June to early July. The flowers are large yellow and red bicolor, but the plant habit is the true winner here, perfect little mounds that do not droop, flop or split. Ok, so I had to add a runner up, also from Terra Nova, 'Imperial Sun'. This variety is a taller verticil- lata type with bright yellow flowers can you pick just one for best of show?" This is not an easy task because having a trial for so long you start to love them all for different reasons. There was one series (ok, so I did not just pick one) that kept catching my eye as well as the eyes of many others throughout the entire trial process — the Leading Lady series from Dümmen Orange. Not only did this series easily bloom for the week 15 Spring Trials event but it has stayed in bloom ever since, 20 weeks and counting! This one is another Darrell Probst hybrid, so like the Big Bang series there are several blood lines (up to eight) that give this series all of its unique characteristics.

Opportunities Going Forward

While there are many coreopsis already on the market, there is still room for improvement. I believe the greatest improvements can be made in the following areas:

• Keep working toward larger flowers that are held above the foliage. This is especially true of the straight verticillata types where small flowers can tend to look a bit wimpy when they are not fully in bloom.
• Continue to work on breeding for uniformity within a series. While some are close, there was no series that was perfect.
• Earlier bloom times for perennial types. While the grandiflora types were having fun blooming for Spring Trials, the other perennial types had little to no bloom. If flower timing was earlier for the perennial types they could get into stores in the spring rather than early summer.
• Stronger, stiffer foliage so that plants do not split in the garden. We noticed once the taller perennial types started blooming they started to drape over the pots. We still need taller plants in the garden to provide height, so it would be great if the taller types could hold up to the weight of their flowers rather than trying to shrink down the plant.
Pacific Plug & Liner is always interested in feed- back on its trials, and we are eager to hear what you would like to see in future comparison trials. For the 2016 Comparison Trials we will be featuring lavender. If you are interested in having your varieties represented please contact us.