NC State Extension

Helianthus ‘Tosca’

Trial: Annual

Years Trialed: 2007

Good Qualities:

Good bright sunflower color (6): Fast crop time (5), about 50 days; Early seedling vigor, early maturity of about 4 to 7 days earlier than Sunrich Orange or Orange Glory; Nice size flower (2); Open face with upward, pointed petals – nice brown center, didn’t droop after being in water for 1 week; Small heads; Nice stem length; Really liked this cultivar, uniform blooming, most all plants produced a flower, seemed to last a long time; Nothing outstanding,my market currently appreciates traditional sunflowers; Early single stem; Very tall- so can cut at the needed length; Standard dark yellow sunflower of average disk diameter and stem length; Good size for bouquet work- stem size was nice and not too big; Pollenless- excellent field and cutting height- nice flower size – nice stout stems- excellent vase life; Good flower quality- big flower size (7.5″ diameter), good plant height – easy for harvesting (slightly taller than “Orange Glory”); Strong stem and neck, good flower posture; The directions from Gloeckner indicated to compare to ‘Sunrich Orange’ – thus, at each planting an equal amount of ‘Sunrich Orange’ ‘Tosca’ and ‘Orange Glory’ were direct seeded – although the seed of ‘Sunrich Orange’ was over a year old it germinated better than either of the two trial cultivars in all four seedings – during the growth phase all three were indistinguishable – however, at flowering ‘Tosca’ flowered approximately 5-7 days earlier and than ‘Sunrich Orange’ and ‘Orange Glory’ flowered at the same time as ‘Sunrich Orange’ at all planting dates – the marketable flowers could not be distinguished by cultivar – in fact ‘Orange Glory’ and ‘Sunrich Orange’ are similar – they could not be identified as separate cultivars; First planting was useless–pollen on these pollenless cultivars, petals in the middle of the cone, misshaped – the 2nd planting yielded beautiful sunflowers; Huge heads.


Some of the flowers were not pollenless (2); Bloomed all at once in the heat of the summer – I didn’t like that each batch couldn’t be more timed, as flowers opened quickly; This did not germinate in three tries – not one flower; None; Short stems; Very daylength sensitive: flowers 17 days later in long days than short day conditions, on a plant that is 44 in. tall, vs. 28 in. for the short day plant; Petals curled back which I don’t care for, makes the flower look “old” and not as fresh; Insects – all came on at once!; Non- uniform flowering window- can’t harvest at the same period – very thick stems- hard to cut/harvest; Erratic germination; Numerous culls due to flowers in the disk, other floral parts in the disk, misshapen heads, double and triple heads, pollen in some heads, very erratic and unpredictable; Misshaped useless flowers; Prone to insect leaf damage.

Similar Cultivars:

Sunrich Orange (2) – the heads were a bit smaller, but had similar color and petal shape; Very similar to Sunrich Gold (2) but about a week earlier; Probably closer to Orange Glory than Sunrich Orange in flower color; ‘Tosca’ is 5-7 days earlier ‘Orange Glory’ and is not different from ‘Sunrich Orange’ in habit and time of flowering.


I would grow this again; I planted 2 varieties for the trials, this variety the seed was treated – this variety was not eaten by birds at planting, the other variety was completely eaten by birds at planting; For our wholesale customers, it is hard to switch them from their reliable standard varieties; For me- it was just another sunflower – trends are changing in this area- large sunflowers as well as small flowered sunflowers are selling well – Procut Sunflowers harvested before this variety; Short day treatment (12 hr daylength for first 3 weeks after emergence) results in plants with short stems and profuse flower bud formation in upper nodes; Harvest a few days ahead of Sunrich Orange; Comparable to “Sunrich Orange” in terms of plant and flowering habit – came into 50% flowering on approximately 5/20/07 (planted 3/9/07, no zone listed), pollenless flowers; Send back to breeder for more work; I liked the similarity of the three cultivars – by having ‘Tosca’ flowering earlier gave me flexibility in harvesting to meet my markets.


Plain water (2) – keep in a cool spot; Cut when petals are ready to open (before the bees get pollinate), we also remove all leaves; Floralife.See separate postharvest report for results from NC State University postharvest evaluations.

Trial Data

Helianthus ‘Tosca’
Plants flowering (%) Plants dead at end of summer (%) Yield (stems/plant) Stem Length (inches) Market Appreciation Rating – Wholesale (1) Market Appreciation Rating – Retail (1) Market Appreciation Rating – Consumer (1) Repeat Again Rating (1) Ease of Cultivation Rating (1)
Average 1.0 40.7 3.4 3.6 3.9 3.4 4.6 88 8.8
Range of Responses 1.0 15.5-72 2-4 3-5 3-5 2-5 4-5 4-216 7-12

(1) 1 to 5 scale, with 5 being the best. Market ratings are based on sales to wholesalers, retailers, or final consumers direct.


Fred C. Gloeckner Company

600 Mamaroneck Ave.

Harrison, NY 10528-1613

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