Pharmaceutical daffodil alkaloid extracts are currently being developed to control Alzheimer's disease. In general, practical factors controlling plant growth-rate are of interest, both in terms of cellular and commercial aspects. In terms of methods, leaf and flower stem longitudinal growth rates are measured for daffodil plants protected by an overhead canopy and compared with those for normal unprotected control plants. Stem lengths and variable geometry diameters are also reported. Results include measurements of leaves and flower stems of normal daffodil plants (N. pseudo-narcissus) growing 0.3 to 0.4 meters in length over a 6 week interval during the Spring. In response to reduced snow, wind and rain forces, and less ambient light, daffodil plants protected by an overhead canopy demonstrate enhanced growth rates, doubling in length to 0.6 to 0.8 meters, over the same time interval, p < 0.0001. The conclusion is that mechanisms for this unusual rate-doubling phenomenon include mechanosensing and/or phototropism, both of which can be controlled with a protective canopy. Practical applications include the development of Alzheimer's control drugs from chemical extracts derived from the narcissus plant.