Growing Bounce in Smaller Pots

Gary Vollmer

Bounce Interspecific Impatiens are a wonderful product that provides unsurpassed performance for consumers and professional landscapers—especially in the shade. However, some of the characteristics that help it perform so well in the garden can add some challenges to growing it.

Two of these characteristics are tied to its very efficient root system: Bounce Impatiens absorb and utilize nutrients faster and more efficiently than any commercial plant that I’ve worked with. This can lead to overfeeding and the responses of the plant associated with that. Second, overwatering Bounce can lead to stretch. In this article, I’ll dive into these challenges and more as we target growing in smaller pots.

Bounce can be grown in liners, as well as direct sticking. In a liner, the preferred size is around a 100 count. Bounce roots quickly and will begin to grow rapidly as soon as roots are present. Liner crop time should be no more than three weeks. Trying to make this a 4- to 5-week liner like most vegetative annuals will be very problematic. Bounce will try to stretch, especially when feeding commences.

As many other species are being leached and are just forming roots, early feeding in prop is a critical step. For Bounce, the roots are formed very quickly and are so efficient, that as other species still need some misting, Bounce is ready to roll and in the liner stage beginning to stretch. The key point here is to get the Bounce liners out of the prop and transplant quickly, three weeks or less. In a direct-stick scenario, the biggest challenge is beginning to feed too much, too early, and the excessive water in the pot from misting.

Pictured: Bounce Impatiens overwatered and too long in propagation.

In addition, Bounce is very sensitive to PGRs. This is common with all impatiens, but particularly on Bounce. We recommend no PGRs. For Big Bounce that will be sold in color in smaller pots, very low PGRs are okay only if needed.

Growing Big Bounce for the landscape can be done in small pots, and even packs, but should be delivered very young and green or budded. For landscape applications, you want the plant herbaceous, ready to take off, so no PGRs are recommended. For retail applications of Big Bounce, a 1-gal. pot is the smallest recommended container size. For smaller retail-ready pot sizes, we recommend growing Bounce. (General guidelines will follow.)

Temperature
Nights: 60 to 65F (16 to 18C)
Days: 68 to 80F (20 to 27C)
Night temperatures above 70F (21C) will delay flowering dramatically and reduce plant quality.

Light
Bounce Impatiens are daylength neutral and will flower year-round. Plants grow best under moderate light intensity. The ideal range would be 4,000 to 6,000 f.c. (40,000 to 60,000 Lux). HID lighting can be used to reduce crop time in areas with naturally low light levels.

Watering
Allow plants to dry slightly between irrigations in the first half of the crop cycle. Do not allow the plants to wilt during this period, as finished quality will be reduced. As the crop matures and begins to bud up and flower, avoid water stress entirely and remember that the crop will need more frequent irrigation. Excessive water stress will cause leaf edge damage, as well as bud and flower drop. “Dry growing” strategies are consistent with other impatiens species.

Fertilizer
Maintain constant fertilization at 75 to 100 ppm N. Excessive phosphorous and ammoniacal nitrogen will promote unwanted vegetative growth and delay flowering. Both should be provided in very limited quantities. Leach pots periodically with clear water to avoid build-up of salts. Avoid low pH and high feed levels as iron manganese toxicity may occur. Keep pH above 6.0.

Bounce Impatiens are naturally self-branching and do not require pinching.

Controlling growth for Bounce
Grow plants with adequate light and space. Avoid high ammonium and phosphorus fertilizers, and do not overwater. Bounce Impatiens will generally flower and be saleable well before any plant growth regulators are needed.

Controlling growth for Big Bounce
B-Nine 1,000 ppm /Cycocel 500 ppm can be used if needed. These impatiens are very sensitive to PGRs, especially Bonzi. Always begin with lower rates. Mature plants that are approaching shipping can be drenched with Bonzi (0.25 to 0.50 ppm) to significantly slow vegetative growth while allowing flowering to continue. These recommendations for plant growth regulators should be used only as general guidelines. Growers must trial all chemicals under their particular conditions.

Crop Schedule & Use
Unrooted cuttings 4-in. to 1-qt. pots (1 ppp): 8 to 10 weeks 6-in. to 1-gal. pots (1 ppp) : 10 to 12 weeks
Rooted cuttings 4-in. to 1-qt. pots (1 ppp): 5 to 8 weeks 6-in. to 1-gal. pots (1 ppp): 7 to 10 weeks GT

Gary Vollmer is Product Manager for Selecta, stationed in the Pacific Northwest. For more culture recommendations, visit www.selectanorthamerica.com.