The Practice and Science of Gardening-4
' What goes on inside the Root'
B. A. KEEN , D.Sc., F.R.S.
Today Dr. B. A. Keen is to tell you how a plant grows by the slow division of its cells, and by the movement of moisture and nutriment through it by conducting-vessels. He will illustrate how one and the same plant may be a comparative pygmy in unsuitable soil, and a comparative giant in soil it likes.
He will talk about plants that bloom for a year and die, and are called annuals -such as godetias, nasturtiums and mignonette. Of those that are sown one year and bloom the next, and are called biennials-such as wallflowers, sweet williams, evening primroses. And of those plants that throw out fresh roots and growth year after year, and are called perennials-such as golden rod, phlox, Jerusalem Cross.
But Schools should remember there may be both annual and perennial kinds of the same variety. For example, candytuft. Again, many of the biennials, if sown early enough, will bloom the same season.