Fancy-leaved caladiums do well in shade, but adapt to sun if they are started directly in the sun from bulbs. In cold regions, start tubers indoors in a mixture of sand and peatmoss in flats or pots and transfer to window boxes when the weather is warm. Tubers need a temperature of
75 to 80 degrees F. to sprout, and will remain inactive for weeks if kept too cool. Tubers may also be planted directly in boxes when the weather warms up, but will take several weeks to make a display.
Patience plant or patient Lucy-in shades of soft rose, pink, peach, scarlet, red, and white-thrives at northern exposures. For trailers you can consider vinca or wandering Jew, either green or variegated, also the silver and purple-leaved zebrina. Tuberous begonias are outstanding performers in window boxes, the large-flowering kinds, with dwarf multifloras along the front. Hanging tuberous begonias create lovely cascade effects in part or filtered shade.
Other plants for shady or partially shady boxes include browallia, with purple cup-shaped flowers, torenia, thun-bergia or black-eyed-Susan vine, pansy, and nemesia. The red, pink, and white wax or semperflorens begonias combine well with grape or kangaroo ivies. A pleasing pair consists of wax begonias and wandering Jew, and these can be rooted from cuttings of indoor plants.
All these plants resent reflected sun from stone or brick facades, but remain crisp and healthy in shade or part shade.
Summer Home for House Plants
Window boxes offer a summering-out place for house plants, provided they are kept out of the scorching sun. Pots can be rested directly in boxes and packed with peatmoss to anchor them and prevent excessive drying. Or cuttings can be taken early in spring to insure a head start. Good trailers among house plants are heart-leaved philodendron, scindapsus, chlorophytum or spider plant, star of Bethlehem, variegated English ivies, strawberry begonia, zebrina, achimenes, German ivy, and lantana, which, though sun-loving, also thrives in partial shade.
Other house plants suitable for outdoor boxes include nephthytis, ferns (with these alone you can do a great deal), alternantheras, foliage begonias, fuchsias, small dracenas, dumb canes, alocasias, maricas, prayer plant, peperomias, asparagus fern, shrimp plant, crown-of-thorns, and bromeliads. If packed in boxes but left in their pots, they can be brought indoors for winter, or cuttings from them can be rooted for the indoor garden.
If you wish, you can combine hardy foliage plants, like pachysandra with trailing myrtle. You might try hostas, though these are really better in larger boxes or tubs. Ferns, both tender and hardy, green and variegated gout-weed, ajuga, artemisia Silver Mound, and variegated gill-
over-the-ground await the imagination of the enthusiastic window-box gardener.