Relationships Between Flowering Phenology & Plant Size

Flowering Phenology

• Flowering times for important crops have been recorded for thousands of years. Farmers look to annual signs as guides for when to plant, treat and harvest. Just as bird phenologists record migration times, gardeners record flowering times each year. While this information might seem incidental, simple garden records have provided important information for scientists studying biologic and climatic change. This study of flowering phenology examines seasonal changes and other factors that affect yearly blooming times.

Plant Size and Bloom Time

• The relationship between plant size and flowering phenology varies. As the Annals of Botany reports, plant size affects other characteristics that also impact phenology. Scientific studies on diverse plant species confirm links and additional correlations between size and flowering phenology. For example, scholars who studied bird's-foot trefoil (Lotus corniculatus), found from U.S. Department of Agriculture plant hardiness zones 1 though 11, observed that larger plants flowered earliest and longest. A study reported in the Journal of Ecology found that maximum plant height and growth rate also affected flowering time. In that study, grassland species that reached their maximum height earliest or fastest flowered first. However, they did not always wait to reach that maximum height before they flowered.

Other Phenology Factors

• Climate provides living things with clues on when to undertake important life cycle events. For flowers, this includes when to germinate, flower, set seed and even disperse that seed. The three main influences are temperature, precipitation and available light. While some animals rely on one or two of factors in their phenology, plants use all three. Other factors that affect flowering phenology include the availability of nutrients and water, soil temperatures, pollinators, seed dispersers and non-beneficial insects and disease.

Why Phenology Matters

• The importance of flowering phenology extends beyond plants. It reveals climatic shifts that disrupt the timing of natural events. Timing can be critical to plant survival and the things that depend on them. Flowers coaxed from the ground too early succumb to late-spring frosts. Ephemeral spring wildflowers hurry to complete their life cycle before foliage blocks the sun. Flowers that rely on pollinating insects become out of sync and bloom before their pollinators mature. Plants remain unpollinated, and pollinators lose their nectar source. In turn, those plants are left without seeds or fruits.