December 2012 Culture, Production

SoCal Tub Trials By Nicole Jackson

Over the past few years Plug Connection has become more focused on vegetative varieties. Our Spring Trials display is known for being the only large-scale objective, side-by-side comparison trial in the industry. I hear from sales reps and growers how valuable our comparison trials are for helping them to learn the finer distinctions between series and varieties on the most popular and newest seed crops. Space and time constraints don’t allow us to showcase all that we’d like at Spring Trials, so our summer tub trial was born to give us more insight into our vegetative varieties and their garden performance.

Using part of our outdoor Spring Trials space with good air circulation and both sun and part sun conditions, we set up the trial just after Spring Trials concluded. The 200 plants were staged over 1,600 square feet in 15 gallon tubs donated by the McConkey Co. and planted in peat-lite soil courtesy of SunGro Horticulture.

Each tub was planted with a 12-inch hanging basket containing five plants per pot. Fertilization with liquid feed (15-5-15) at a rate of 200-ppm nitrogen on a rotation of two days of fertigation followed by a day of clear water kept them green and looking good. The weather in north San Diego County is typically very mild from May to September. Temperatures are very consistent and daytime highs range from 71 to 82° F and lows between 51 to 63° F, peaking in August. It’s southern California, so the weather is rarely extreme and usually fairly awesome! This summer, we had nearly a week of very hot weather with temperatures in the high 90s and low 100s, topping out at 102 to 104° F. This provided a lot of stress-pressure on plants accustomed to the cool and consistent temperatures, and allowed us to see some stand-outs.

I walked the trial regularly with Juan St. Amant, who manages new product development at Plug Connection and Gregg Opgenorth, our vegetative production manager. We took lots of notes and discussed the plants’ progress frequently to judge what we think were the standouts of the season.

Top New Variety Selections

Two geranium series that impressed us and our visitors were both from Elsner-PAC in Germany. Aristo is a substantial improvement on traditional “Martha Washington” Regals and selected for better heat tolerance and less dependent on a long chill. Favorite selections included the large-flowered ‘Aristo Clarina’ and ‘Aristo Petticoat’. The Candy Flowers series, a smaller and more heat-tolerant “multi-flora” Regal, was just a spectacular show all summer long with smaller flowers than Aristo but so many of them, you could hardly see the leaves. Even in the heat wave we experienced, the plants in both series managed to continue looking good. ‘Candy Flowers Bicolor’ was our hands-down favorite and just kept going! Growers with outdoor or cool production capacity for this crop should bring in rooted cuttings in the late fall to bulk plants over the winter and vernalize with average night temperatures between 40 and 50° F (always above freezing). Plants will flower in early spring as temperatures increase. “If I were still in the finished plants business, these would definitely be on my bench in a big way,” says Gregg Opgenorth.

Salvia ‘Saucy Red’ from Cultivaris North America was a real show-off and looked great all summer. It’s a sterile hybrid, so it never sets seed and continues throwing new blooms constantly. In California under our high light levels, Salvia spendens varieties do best in partial shade. Large 6- to 10-inch spikes cover the plant, which matures at around 36 inches. Growers should note this will be a fast crop and it flowers very early. Crops in 6-inch or gallon pots are ideal for quick turns, four to six weeks with one plant per pot. High-end growers will see value as a larger pot (8 inches or specimen) with large mixed containers.

Verbena ‘Lanai Candy Cane’ from Syngenta was a favorite novelty in the trials. The habit was controlled and the flowers never petered out in the center or during hot weather. Even when other verbena had fallen from Botrytis and extremely hot weather, ‘Lanai Candy Cane’ just kept showing off. I’d pair it with supersaturated purples, true blues and deep yellows.

Tecoma ‘Bells of Fire’ and tecoma ‘Lydia’ were excellent performers in our hot summer. These two varieties had flowers all summer long in profusion and with a much more compact, branched habit, they lend themselves to a range of sizes and uses. ‘Bells of Fire’, with it’s gorgeous orange-red flowers and ‘Lydia’, with large, bright clear-yellow flowers absolutely love the heat! The compact habit makes them an easy choice for quick summer color in colder climates. Colorado State University named ‘Bells of Fire’ the Best New Novelty in their well-respected annual field trial. I believe these have great promise as a summer color item in Northern states, and in the South they are drought tolerant and hardy to Zone 9. They will take more abuse and less water than a lot of other plants and offer high impact color that will fit well in any sunny space.

SuperCals from Sakata were almost exactly what their marketing materials claim. A unique cross between petunia and calibrachoa, you see distinct characteristics of both genera. The calibrachoa-type flowers are 2 inches wide and the foliage is not sticky. Habit is vigorous like a petunia and mounding, cascading. Even when stressed, their heat tolerance is exceptional. At my house on the coast (cool, foggy early summer weather), they continued flowering in a small container with infrequent waterings and very little food. They thrived, despite the inconsistency of my horticultural love. I think these are destined to take more of the basket and container market because they’re a lot friendlier to the abuse of the home garden.

Acalypha Tiki series from Cultivaris, was selected for unusual foliage forms, better branching and fewer flowers. It’s great in small and large pots once the night temperatures begin climbing. With strong growth all summer long, our favorites were Lava Flow, Tropical Tempest and Jungle Cloak (new for 2012). Lava Flow has coffee-black foliage with hints of orange tones. Tropical Tempest sports trendy patterns and gradients of chartreuse green. Jungle Cloak has unusual almost camouflage-like leaf patterns with dark and light green splashes, and irregular patterns. In warm climates the Tiki series is a great replacement for coleus because they’re a lot more forgiving for the average gardener and tolerant of a greater range of temperatures and extremes in care.

Lobularia ‘Silver Stream’ from Danziger showed well in our trials. It’s a more refined plant than the established variety on the market and thus works better in combos because it won’t overwhelm or be overwhelmed by calibrachoa and nemesia. ‘Silver Stream’ has not stopped flowering since it was planted before Spring Trials. The clear white flowers and a nice tight habit mean that this variety is likely to be standard for years to come.

Abutilon Lucky series from Plant Haven improves on older varieties — with smaller leaves and larger, more outward-facing flowers. This series shows off at retail nicely. With a good habit in a 41/2-inch to 1-gallon pots, this series is great for part shade or full sun or in combos. It showed strong performance all summer, even through our hot spell.