Water-lilies are naturalized on a great scale at Gravetye, and the picture on plate 20 shows a corner of one of the lakes where the water-lilies are just coming into bloom. This is a department of gardening in which we have a chance to excel England, because our hot summer sunshine brings out richer colours in these gorgeous flowers.
It will be many years, however, before we shall plant the margins of water with such consummate taste as Mr. Robinson. He gave a pretty full list of the plants he uses in that superb English periodical, Country Life Illustrated, on March 6, 1909. About the only important plant in the list we cannot grow is pampas grass. He uses many kinds of willows to obscure the line between land and water; Siebold's knotwort (Polygonum cuspidatum) for great billowy masses of foliage; the moon daisy (Pyrethrum uliginosum) for lush, herbaceous growth and clouds of white, daisylike flowers; and the royal fern for delicate greenery.
But these are only samples. His grand effects come from purity of design, i. e, using water-loving plants only. "One essential thing," he says, "is the avoidance of variegated rubbish. Some of the finest lakes I know are spoilt by being freely planted with variegated conifers, which always, and usually very soon, take a diseased and ugly colour. The variegated elder is planted in the Serpentine, a plant that should never be seen near water." I fear we are too often guilty of leaving a bare margin, setting out beds of cannas or other tender plants by the waterside, and planting Colorado spruce, Waterer's spirea, or anything that seems to us beautiful in itself. Such plants are beautiful in their place, but painfully inappropriate by the water side. And it seems like criminal stupidity to do this sort of thing when the moist soil is yearning for the swamp rose mallow, the cardinal flower, Lilium superbum, rhododendrons, mountain laurel, purple loosestrife, red-twigged dogwood, and wild rice. All of these are native, and therefore we ought to grow the finest masses of them in the world.
Of foreign species we should use only those that demand an extra good water supply, look wild, cost little, and require no care after planting. We can no longer plead ignorance, for there are many catalogues now which give separate lists of plants for the waterside. Some of the most splendid examples are the tall yellow iris of Europe, the Japanese irises, the Siberian iris, the hardy evergreen bamboo, the giant reed, the white and yellow loosestrife, and the globe flower.
One of the most charming water side effects at Gravetye is that of the lemon lily (Hemerocallis flava), a bit of which is shown on plate 25. Please do not confuse this with the coarse orange day-lily (H.fulva). This lemon lily is a common garden plant, but it looks its best at the water side, because its narrow leaves blend with those of the tall grass and both can be cut in July, if necessary, without harming next year's bloom.