86 Commercial Gardening 



crimson and red and allied shades has been gradually evolved from the 

 above-named hybrid, itself the result of crossing Primula acaulis and 

 P. officinalis. It is one of the most popular of spring-flowering plants, an 

 old-time favourite, whose popularity is not a little due to perfect hardiness, 

 great freedom of flowering, and simplicity of culture. The plants delight 

 in rich soils and cool and shady spots; hence it is a success in orchard and 

 woodland, or in soils where much moisture is found. 



Though by nature, in common with its original parents, of perennial 

 duration, it is for effective garden decoration far better if regarded as 

 a biennial only, to be raised periodically from seeds. Seedlings, indeed, 

 possess the greater vigour and provide that freedom of flowering every- 

 where admired. 



The seeds should be sown in March or April in shady spots in the open, 

 or in boxes or pans in frames, and be transplanted when three or four 

 leaves have been formed. Not a few amateur and private gardeners post- 

 pone the sowing of the seeds to August, or even later, evidently working 

 on the new seed-crop theory. Seeds sown at this latter date, while vegetat- 

 ing early and well, cannot overtake those sown a few months' earlier, and 

 since size of plant in this instance means also a great flowering, the period 

 named should be followed. Seeds of Polyanthus are most impatient of a 

 deep soil covering. Far better that the seeds be thinly broadcasted on 

 a well-prepared bed of soil, well watered in, and left alone to nature. In 

 this way they are washed into the interstices of the soil and require nothing 

 more. Rich food or abundant moisture, or their partial equivalent, shade, 

 are essential to success, their opposites but court failure by starvation. 



Seeds of many high-class strains are available at the present time, and 

 among these the "Munstead" strain calls for special mention because of 

 great size of blossom and a wide range of colours. A point of importance 

 to the grower of this crop is the ever-present need for further improvement, 

 best accomplished by cross-breeding, selection, and re-selection, which 

 naturally includes the elimination of the degenerates. A profitable crop, 

 of which the seeds and the plants are alike saleable. The Polyanthus is 

 a great favourite with some market growers, who plant it between the 

 rows of standard Apples, Pears, or Plums, about 1 ft. apart, or less, and sell 

 the "roots" in boxes in the spring. Forty thousand plants to the acre may 

 be taken as a fair crop. [E. H. J.] 



PolygfOnatum. Besides the Solomon's Seal (see p. 100) there are a 

 few other kinds, such as biflorum, 1-3 ft.; japonicum, 1-2 ft.; latifolium, 

 24 ft.; officinale, 1 ft.; oppositifolium, 2-4 ft.; punctatum, 12 ft.; and 

 verticillatum, 2-3 ft. all with greenish-white flowers. P. roseum has 

 pinkish blooms. 



Polygonum (KNOTWEED). A large genus of vigorous-growing plants 

 chiefly dealt in by hardy-plant growers. The best-known member of the 

 genus is the beautiful Japanese knotweed (P. cuspidatum or Sieboldi) 

 which grows 6-10 ft. high, has large heart-shaped leaves and trusses of 

 white flowers in summer. This plant flourishes in any spot and in any 



