P&PDL Picture of the Week for
June 22, 2009

Premature Budding and Flowering of Garden Mum

Roberto G. Lopez, Ph.D., Assistant Professor & Floriculture Extension Specialist, Purdue University

Garden mums that finish short or too early are usually the result of premature budding that occurs when plants are stressed.  More specifically, crop exposure to low night temperatures, short days, drought or nutrient stress can lead to premature budding (Figure 1 and 2). 

Garden mums are short-day plants. When grown outdoors, growers rely on natural photoperiod (daylength) and temperature to control the timing of the crop. Temperature can have a greater influence than photoperiod on floral initiation and early development of garden mums.  It is not uncommon for garden mums in northern latitudes to be exposed to cool nights in June. With several consecutive cool nights (<50 ºF), garden mums can initiate buds prematurely which results in early flowering and short plants.  Premature budding can also be a result of stress from exposure to very high temperatures in combination with low humidity or excessive rainfall.  If premature budding occurs, buds should be pinched off immediately, and adequate moisture and fertilizer supplied. 

It is also import to note that heat delay or the delay of floral initiation and development can occur if plants are exposed to excessively high temperatures (>85 ºF) during the early portion of short days.

Click image to enlarge

Figure 1

Figure 2

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service