Sometimes China asters have rusty or yellow spots on the undersides of their leaves. This is a fungous disease. If it appears, have your father make some ammoniacal carbonate of copper solution and then spray them with it; or Bordeaux mixture will do just as well or better, only that it discolors the leaves and flowers. _5. What varieties to choose._--In the first place, do not plant too much. A garden which looks very small when the pussy willows come out and the frogs begin to peep, is pretty big in the hot days of July. A garden four feet wide and twenty feet long, half sweet peas and half asters, is about as big as most boys and girls will take care of. [Illustration: _Fig. 271. A clump of weeds in the corner by the house,--motherwort and Virginia creeper. How pretty they are!_] In the next place, do not get too many varieties. Four or five kinds each of peas and asters will be enough. Buy the named varieties,--that is, those of known colors,--not the mixed packets. If you are very fond of reds, then choose the reddest kinds; but it is well to put in at least three colors. The varieties which please you may not please me or your neighbor, so that I cannot advise you what to get. Of China asters, the Comet type--in various colors--will probably give the most satisfaction. They are mostly large-growing kinds. Other excellent kinds are the Perfection and Peony-flowered, Semple or Branching, Chrysanthemum-flowered, Washington, Victoria, and, for early, Queen of the Market. Odd varieties are Crown, German Quilled, Victoria Needle, and Lilliput. Very dwarf kinds are Dwarf Bouquet or Dwarf German, and Shakespeare. One of the chief merits of the China aster is the lateness of bloom, allowing the flowers to be used in the schools after they open in the fall. An excellent flower for sowing during May is the common annual Phlox (_Phlox Drummondii_ of the catalogues). Poppies are also satisfactory, but the flowers do not last long. Petunias are excellent and Balsams, Clarkias, Coreopsis (or Calliopsis), and Zinnias may be sown. Now, let us see how many boys and girls in New York State will raise sweet peas and China asters this year! And we should like them to write us all about it. LEAFLET XXXIX. A HILL OF POTATOES.[53] BY I. P. ROBERTS. [53] Nature-Study Quarterly, No. 7: Leaflet 20, January, 1901. [Illustration] Plant a hill of potatoes. You can do it in the school-room. Plant in a box or a flower-pot. Keep the box warm, and do not let the soil dry out. Plant whole tubers and pieces of tubers. Plant pieces of various sizes. Plant some that have no "eyes." Plant shallow--so that the tuber is just covered with soil--and deep. Watch the results.