Profusion zinnias are summer garden favorites due to their durability in the landscape and continuous color. They have strong, durable foliage that resists insects and repels browsing deer and rabbits. Plus, Profusion zinnias have the added benefit of strong disease tolerance to alternaria and powdery mildew. Available in both single and double flower forms, Profusion combines nicely with other annuals or alone in a feature bed.
The Profusion series is an interspecific cross between two species Zinnia elegans and Zinnia angustifolia, inheriting the large flowers from the elegans parent and the disease tolerance from the angustifolia parent. In the landscape Zinnia Profusion grows well in both cool and warm climates. New canopies of flowers continuously cover the old blooms for a clean and natural look.
Zinnias require a well-drained soil where water does not pool after heavy rains. Zinnia roots do not tolerate heavy, compacted soils or standing water which invites disease, like sclerotinia. In the garden Profusion will eventually grow 16-18 inches tall and 20-24 inches wide, depending on the length of the growing season and soil type.
For greenhouse growers, Profusion zinnias offer great germination percentages at 90%+. Profusion’s high seed quality yields more useable and transplantable seedlings. Plus, their strong and early vigor will allow Profusion to be transplanted easily with automatic transplanters with minimal mechanical damage. Generally a fast-turn crop, Profusion will finish in as little as 9-10 weeks in large packs, 11-12 weeks in larger-sized containers and hanging baskets. Normally, zinnias are seen at retail once warm weather has arrived for the season; but don’t underestimate Profusion’s durability in the retail market. Profusions can be shipped with begonias, salvias, and impatiens, and with the great new colors of the Double Profusions, extra sales can be achieved, with follow-up orders all but assured.
- Select a well-drained, porous media with a pH of 5.8 – 6.2 and EC <0.6 mmhos.
- A 288 plug tray works well and is ready for transplanting in 4 weeks.
- Water in the plug tray to the point of drip prior to sowing. Then, sow the seed and cover with coarse vermiculite. Do not water after sowing or the day following sowing. Then, apply moisture as needed for germination (Level 4, wet but not saturated).
- Optimum germination temperature is 76ºF/25ºC.
- After cotyledon expansion, apply 50-75 ppm N from a Cal/Mag formulation (13-2-13-6 Ca-3Mg). Then, fertilize at 100-150 ppm N to maintain the EC at 1.0 – 1.2 mmhos (2:1 dilution). Boron should be applied at 0.25 ppm to ensure healthy growth.
- After emergence reduce humidity and target a temperature of 68-70ºF/20-21ºC.
- Zinnia Profusion forms flower buds quicker when the days are short (<12 hours). To ensure sufficient plant size, provide long days (night interruption for 4 hours or day length extension to 14+ hours) with a minimum of 10 foot candles/110 lux in the plug stage. For larger containers select a lower density plug tray (72 cell) and light for 6 weeks or else continue lighting the plants after transplanting a few additional weeks.
- Higher light levels (8-10 moles) promote faster bulking and basal branching.
- For finishing, target the EC between 1.2 – 1.5 mmhos and fertilize with calcium nitrate-based fertilizer. To ensure adequate boron levels, target 0.25 ppm B at each irrigation and maintain optimum pH (5.8-6.2). Periodic applications of magnesium sulfate (MgSO4) at 30* ppm Mg ensures a deep green healthy leaf color (*4 ounces/100 gallons).
- Optimum finishing temperature is 65-70ºF/18-21ºC.
- For height control use negative DIF, pinching or B-Nine at 2,500 – 5,000 ppm. Avoid over regulating the plants to ensure customer satisfaction.