Top picks of industry personnel during the mid to late August 2008 growing season
1) Rudbeckia ‘TigerEye Gold’
2) Zinnia ‘Zahara Scarlet’
3) Lantana ‘Landmark Sunrise Rose’
4) Sedum ‘Angelina’
5) Zinnia ‘Magellan’ series
1)Rudbeckia ‘TigerEye Gold’ generated a lot of interest in every trial I attended in 2008. This F1 hybrid is propagated by seed and has a very consistent growth habit, giving an even and predictable look to a mass landscape planting. In the combined LO/Guelph Trials we planted out relatively small plants (i.e. the equivalent of an 806 garden pack) in mid-June and had a full bloom presentation by mid-July. The plants bloomed non-stop and abundantly until frost damaged the flowerbuds in early October. Our observations this year suggest that this rudbeckia is resistant to powdery mildew. The literature suggests that ‘TigerEye Gold’ should be treated as an annual; we left the plants in the trial beds for the 2008/2009 winter to observe this for ourselves but until you hear differently, it can’t be assumed to be winter hardy. When using small plants, as we were, in the landscape try planting at spacings of 8 inches for fast fill-in. With larger plants (i.e. 4") you can space at 12 inches. This plant will spread to at least 16 inches during the growing season and reach heights (in full sun) of approximately 18 inches. Consider planting in combination with a purple spike-like plant such as Salvia ‘Mystic Spires Blue’; the gold and purple compliment each other very well.
2)The two zinnia series that were the most popular in 2008 were ‘Magellan’ and ‘Zahara’. The petals stood up well to the exceptional rainfall we experienced last summer and both of these series tolerated disease pressure well into September. The ‘Zahara’ zinnias are selections of the Zinnia marylandica and closely resemble ‘Profusion’ zinnias in terms of flower form (daisy- like), size and disease resistance. The garden height and spread of the ‘Zahara’ series is 12-18 inches; plant spacing of 10-12 inches is adequate for a fast fill-in. The scarlet colour seemed to be the most popular colour amongst visitors to the garden but ‘Zahara’ cultivars of white, coral rose and yellow are also available.
The ‘Magellan’ zinnias are selections of Zinnia elegans and display the large and showy flowers of the “traditional” zinnia. ‘Magellan’ is available in 8 colours ranging from ivory to yellow to orange to cherry; all plants within the series had a similar growth habit and bloom performance and the favourites chosen by visitors depended upon individual colour preferences. The garden height of this cultivar is 12-14 inches; a spacing of 8-10 inches for 806 sized plants is adequate to achieve a quick canopy fill-in.
3)In the 2008 Guelph trial we had 10 lantana entries. This tropical shrub is used as an annual in landscape beds and containers; some cultivars are trained to form standards to add some height to a container or bed. Lantana is very tolerant of heat and has colours ranging from white to yellow to orange to purple. Many lantana cultivars have flower clusters that change colour as the individual flowers age; in the case of this year’s favourite, ‘Landmark Sunrise Rose’ the florets open yellow and then turn orange and pink as they age. The lantana bloomed constantly throughout the summer up until frost. The lantana in the 2008 trials varied in vigour and grew to heights of anywhere from 15 to 20 inches. Although the flowers of ‘Sunrise Rose’ were extremely showy, it was the least vigorous of the ‘Landmark’ series. The plants for the 2008 trial were grown in 4 inch pots and planted out at 12 inch spacings; ‘Sunrise Rose’ should have been spaced at 10 inches to fill-in faster than it did.
4)New for the 2008 trials this year was a selection of sedums that were planted out in the non-irrigated trial bed. 2008 turned out to be a poor year to test drought tolerance of landscape plants and as consequence we ended up testing the rain tolerance of some species of succulents. One that stood out as exceptional to the visitors to the trial garden was ‘Angelina’, a selection of the species Sedum rupestre. During the warm part of the summer, this plant with it small needle-like foliage was a yellow-green in colour; as fall temperatures arrived, the foliage turned a brilliant yellow-orange. According to the literature ‘Angelina’ should be hardy to USDA Zone 3. The plants for this trial were propagated in the greenhouse and finished in 4 inch pots. They were planted in the garden at 12 inch spacing. This spacing was a little too generous to allow for a quick, first season canopy fill-in; 6-8 inches would have been better. Overall height of the plant in the trials was 3-6 inches.
