P&PDL Picture of the Week for
February 21, 2011

Scheduling Bedding Plants

Roberto G. Lopez, Ph.D., Assistant Professor & Floriculture Extension Specialist, Purdue University and Christopher J. Currey, PhD student, Purdue University

Properly scheduling your bedding plant crops can reduce crop losses (shrink), fuel consumption, and labor while increasing plant quality.  Shrink, the plants that do not sell for one reason or another, can be reduced by ensuring that plants are in flower and at their peak quality at the times when customers demand them. 

If you want to sell your plants with color on them, knowing how to induce flowering will help you get the crop flowering by your target sales date.  If you are growing plants under a non-inductive photoperiod, you will increase production time just waiting for them to flower!  Let’s say you want your lobelia crop in flower for Easter weekend sales, Week 16 (Figure 1).  It is a long-day plant that flowers about four to five weeks after the start of long days.  To get plants flowering by the target sales date, you’d want to start long days during Week 11. 

Alternatively, if you are trying to bulk plant up to fill in a container you don’t want to grow them under photoperiods that result in flowering immediately after planting.  Take a seed-propagated petunia crop in 1-gallon pots (Figure 2, plant on the left).  Since they flower in response to long days, you’ll want to keep plants under short days for a few weeks after transplanting to promote vegetative growth and not flowering.  After plants have reached a certain size, they can be placed under long day conditions to promote flowering for sales.

Click image to enlarge

Figure 1

Figure 1. A lobelia crop that was not placed under an inductive long day photoperiod and as a result is vegetative near the market date of Easter weekend.

Figure 2

Figure 2. A petunia crop that was exposed to inductive long days during propagation (left) and a petunia that was propagated under a non-inductive photoperiod.

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service