“Plant the slip in your window box, burying it in earth above the first node; that is, the node just above the cut.  Thus you have buried in the earth the place where roots will form.

“Crowd the slips in, three or four inches only apart.  They should not be exposed to the full glare of the sun at first.  Some gardeners say to let the slips wilt before watering.  But it is quite safe to water a little from the first.  Do not soak the soil, however, or the young plants will decay.

“Now the slips may be put right into a window box, or into these flats.  I would not place them immediately in a sunny window.  But place them where the sun does not shine directly.  It is excellent to leave window boxes and newly potted plants outdoors for a time, until in the fresh air they get accustomed to their new living conditions.”

“Shall we fix up the school window boxes now?” asked Josephine.

“Yes, we will get right at that.  But first I will give you a window-box talk.

“The most satisfactory way to grow plants in the schoolroom and in many cases, at home, is in the window box.  The window box means the possibility of easily caring for a number of plants in a small space.  Plants in pots take much more space than the same number of plants in a window box.

“It is the cleanest way, too.  You are all familiar with the sight of a pot covered with crepe paper stained and discoloured from water spilt upon it and moisture given off from the porous pot.

“The window box, if properly watered, need never leak.  Its freshly painted sides need never be covered with any material.  It stands for just what it is—­a well-made, well-painted wooden box.

“It is quite impossible to give dimensions for the construction of the window box, since it must fit the space one wishes to use.  It is wise to keep in mind this—­that these boxes when filled with soil are very, very heavy and awkward to handle.  So if your window is large, why not have two small boxes for the space rather than one large one?  When these are placed end to end the effect is of one long box.  The ordinary house window may well have the single box.

“Other things to keep in mind for the constructing of the box are depth, drainage, holes, joints and paint.

“Just as bulb boxes need no great depth, so with window boxes.  If the depth be great the plants spend too much energy in root growth.  A shallow box means, if properly filled, a compact root mass.  So if your box is to be, say three and a half feet long make it not more than ten inches deep.

“As we make drainage holes in the bottom of the bulb box, so we do in the window box.  Many people make window boxes without drainage holes.  It seems rather better to have them since they offer exit for surplus water, and places for the roots to get at the air.  These holes may be bored six inches apart down through the centre of the box; or they may be bored in two lines, thus doubling the number of holes and the amount of air space.  Take this rule, for every square foot of space have four drainage holes.