The epidermis of petals also form a variation of trichomes called conical cells. These cells all develop from the pavement cells, which make up the majority of the plants surface cells. In short, cellular differentiation of the epidermal cells is controlled by two major factors: genetics and environmental conditions.
Azaleas and rhododendrons thrive in acidic soil. Azaleas and rhododendrons thrive in the acidic soil that is common under pine trees. Both plants are classified under the genus Rhododendron; the main difference is the smaller, funnel-shaped flowers on the azalea.ake soil samples from the area under the trees where you want to plant the azaleas or rhododendrons. Mix the samples in a bucket and test with a soil pH test kit.
It can take 2-3 years after. It can take 2-3 years after planting for rhododendrons to bloom. There are also many other reasons for a lack of flowers and some varieties bloom less than others. Cold temps. in the spring can kill new buds. Most large-leaved varieties require dappled shade; avoid deep shade or full sun. 2  A sunny spot that receives a few hours of shade is perfect. 3  Soil should be well-drained, humus-rich, moist, and acidic (pH 4.5â6). 4  Amend planting areas with compost, peat moss, or a substitute, and oak leaves to achieve ideal conditions.