120 



H E T 1 C U L T U ]{ !• 



August 10. 1918 



ting with a | inch mesh. The top soil ot the seed bed 

 must be sifted through this or a finer sieve. Make it 

 six by three feet, of two inch plank. Mount on two 

 wooden horses above the trench and work soil and 

 muck through with a hoe. We know that stones disin- 

 tegrate into the soil and some furnish potash, but 

 there will be enough pass through the sieve. The rate 

 of disintegration is interesting and will form the sub- 

 ject of a future letter. 



Fertilizer 



IMuck needs potash and phosphoric acid. To every 

 thirty feet in length of the bed add twelve pounds of 

 the following mixture, as soon as the bed is made, 

 working fertilizer, dirt and muck together with a spad- 

 ing fork: Slag phosphate, 750 pounds; sulphate of 

 potash (the best you can get), 225 pounds; perman- 

 ganate of potash, 25 pounds. If you believe in radio- 

 active soil add four ounces of oxide of thorium. 



Time for Planting Iris Seed 



In this climate planting conies the first week in Sep- 

 tember. Plant the seed (which should be the color of 

 coffee and milk) one inch deep, one inch apart, in rows 

 with only room enough to place a foot in weeding, not 

 over six inches. As all the work in the seed bed must 

 be done by hand, the plants should be near together, 

 to make the space for weeds small, for labor is very 

 costly. Weeds grow faster than the plants. Clover is 

 particularly troublesome, for its • roots go deep before 

 the leaves are large enough to grasp. 



What Proportion of Seed Will Produce Strong 

 Plants 



This varies greatly with the cro.ss. From one of the 

 pods shown in Figure 9 I selected 133 of the 150 seed~ 

 and planted them. They produced 77 strong-growing 

 plants. For this climate that is a good result. Two 

 thousand seeds of another .mowing the same year gave l)ut 

 107 plants. I have repeatedly crossed Macrantha on sev- 

 eral of the best tall growing kinds. The seed pods were 

 exceptionally large, as were the seeds, but the germina- 

 tion was very poor, averaging five per cent. Another 

 person might get quite a different result. I abandoned 

 the use of Macrantha, as the erect segments of the 

 perianth were too floppy, and considering tlie poor 

 germination the chance of breeding this out and yet 

 retaining the large size of the flower seemed remote. 



Growth of the Seedlings 



The following May after jilanting, the plants should 

 be above ground. By the last of June they should be 

 from three to six inches tall, according to the cross. By 

 the first of August they should lie from eight to twelve 

 inches. The first time you dig seedling iris you will 

 be surprised to find the |iarts under gi'ound do not look 

 like rhizomes. They are somewhat globular with the 

 rootlets arising from their bases. The rootlets are 

 about two-thirds as long as the leaves. 



Transplant Garden 



Make it the same width as the seed bed but longer. 

 Prepare in the same w;iy. 



Transplanting the Seedlings 



Do this the first week in August. Plunge a large 

 mason's trowel into the ground eight inches. Draw the 

 blade back, leaving a cavity into which drop the seed- 

 ling, with the rootlrts hanging; withdraw the trowel 



allowing the earth to fall bai-k on the roots. Firtu it 

 with the feet, leaving the bulbous part of the root two 

 inches lielow the surface. Set the seedlings six inches 

 apart, in rows with six inches between them. 



Watering 



\\l\en the lied is ]danted, run the sprinkler, if tlio 

 seastm is dry, until the ground i; inoist. and will hold its 

 form when squeezed in the hand. 



Growth and Mortality in the Transplant Bed 



<Jniy one per cent may die the first winter. At the 

 end of the second 95 per cent should be alive. One 

 [ler cent should flower the first year where many kinds 

 of crosses are made. Xinety-five per cent should blos- 

 som tiie following season. 



Ta„nc.rth, N. H. ^'^ lllUv^v ]\ol[[X^^ 



( Tn 'u' i iiiirJinJfd) 





