Pennsylvania School of Horticulture for Women - Wise Acres Yearbook (Ambler, PA)

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School of Horticulture It is quite a good plan to cover the roots in winter to protect them. This may be done either with sand or wood ashes and a little mound of either sand or wood ash may be placed around each crown. This keeps the crown fairly dry during winter and prevents the young shoots from rotting. Until quite recently there has been practically no disease which has attacked Delphiniums and bugs were apt to get rather scared of the healthy, vigorous plants or perhaps they had respect for the handsome foliage and refused to destroy it. Anyhow the Delphinium was left severely alone so far as the insect world was concerned. Only in very neglected ground did one find a few millipedes, wood lice, and wire worms, which did some damage. To prevent these attacks the soil should be cultivated and also fumigated. For fumigation, small holes about three inches deep should be made and a fresh, dry mixture of the soil vaporizer (one spoonful to each hole) should be put in the ground, covered with soil and left undisturbed for ten days before planting. Delphiniums are sometimes attacked by mildew and in such cases precautionary measures should be taken. The preventative which is most commonly used is sulphide of potassium. This is dissolved in hot water and then rain water is added to make a two and a half gallon solution. The plants should have three sprayings, first, when the shoots are about twelve inches high and then later and again when the flower spikes begin to show. On cold soils, Black Rot Fungus sometimes appears at the base of the stems, penetrates to the crown of the plant, and causes decay of the entire root-stock. This disease, however, may be checked by improving the drainage of the soil and also by surrounding the plants with charcoal. Several years ago a peculiar “blight” attacked Chestnut trees all over the country and killed them. Although research work was done to find out the cause of the blight and how to prevent it from spreading, nothing definite was really found and practically all the trees were killed. In our woods there are still some of the diseased trees which show us what handsome trees the Chestnuts were. Now, something of the same nature is trying to kill off many of our fine Delphiniums. Last year the Journal of Agricultural Research published an account of the work done in connection with Delphinium Leaf Spot. In short, it stated that bacterial Leaf Spot on Delphiniums occurs north from Pennsylvania and westward from Maine to Illinois. It is interesting to note, that it occurred in the West in one place only, in Washington State. The spots of the disease are irregular in shape and about one to two centimeters in diameter. On the under side of the leaf the spots are small and brown and later when more developed, the spots are tarry black on the upper surface of the leaf. The old spots, however, do not have water-soaked edges like most bacterial diseases. In its very early stages, it can be readily seen with an ordinary lens. The lower surface appears to be sunken while the upper surface of the spots is slightly raised. Spots occur on the leaf blades as the result of stomatal infection and they are also common on the tips of the leaves where they make their entrance through the water pores. When infection takes place on the young leaves, distortion usually results from the failure of the diseased areas to keep pace with the growing healthy tissue. Flower buds are occasionally attacked and become black and distorted and the petioles and stems are also attacked. In later stages of the disease the spots coalesce and form large areas, sometimes covering the entire leaf. The climatic conditions play quite a large part in the development of the disease. In spring, cold, moist weather is very favorable to its growth, while in winter T wenty-seven

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Wise-oAcres removing the top soil and forking well-decayed manure into the sub-soil and then placing the top soil on its previous place. When the soil is prepared, the Delphiniums, which are usually one-year-old plants, are planted. This is usually done in spring when the plants begin to grow, but if the garden is well sheltered and the soil well drained, they may be planted in the autumn and that gives them enough time to settle before the frost comes. If arranged in beds, they should be planted about three feet apart, as they grow into quite large plants, but if used among other per' ennials they should be planted in groups and at least a space eight feet square allowed for each group. The best position for Delphiniums when planted in a wide herbaceous border is from the middle to the back. The position of the border where the Delphiniums are to be planted should be airy and sunny but not windswept. If the soil is of a light nature a top dressing of organic manure with bone meal, meat meal, or dried blood produces better results than a combination of sulphates, nitrates and so forth which have no organic substances in them. On a heavy soil, chemical manure gives the best results, if some humus forming material has been dug in before planting. The best method of application is to sprinkle the fertilizer in a ring around each plant about twelve inches from the crown of the plant. The fertilizers should be applied in small doses at intervals of ten days or two weeks. They should be applied after rain and worked into the soil the following day. There are three methods of propagating Delphiniums, the most common way being by seed, but division of old plants is often practiced. Cuttings, if taken in spring or after the plant has finished flowering, root readily if inserted in sand and kept well shaded. If propagated in this way, they should not, however, have any bottom heat; they benefit by being frequently syringed with water during the hot summer says. Cuttings should be three to four inches in length and they should be cut immediately below a node. After they are rooted, they should be potted on or planted out into nursery rows. Seed of the perennial Delphinium should be sown in February' or March in the greenhouse or in a hot bed. The seed usually germinates very slowly. When the seedlings have two or three true leaves they should be pricked out into boxes or potted on into small pots so as to give them enough room to grow, and also to prevent damping off. Later on, about May, the plants may be planted out in nursery rows, provided it is done carefully and the plants are looked after for several days until they are properly established. The seedlings should, in late summer, produce one or more spikes of lovely flowers. If seed is sown out-of-doors during spring, the plants should be well looked after during dry weather, and these seedlings should flower in the following season. If Delphinium plants are rather large in a perennial border, they may be taken up and divided and then transplanted. This is usually done in spring when the new shoots appear, or in summer after their first flowering is over. If done in summer, the plants should be cut down and allowed to start fresh growth and after that the plant may be dug up, divided, and transplanted again. Summer division should be done in wet weather, otherwise great care must be taken in watering and shading the plants until they get established. Delphiniums can be kept flowering for several months by continually cutting the spikes after they have flowered and thus preventing them from seeding. If the central spike is removed, the lateral and the new basal shoots begin to flower and so quite a succession of bloom may be obtained. But if this constant blooming goes on, care must be taken to provide the plants with nourishment in the form of a dressing of decayed manure or an application of liquid manure. A top dressing keeps the soil moist and cool and produces healthy growth and vigorous blooms. T wenty'Six

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W ise-oA cres the organisms live in the soil and are able to resist much cold and dryness. It has also been found that the lower leaves are infected first from the soil. On this account all diseased parts should be gathered and burned and the soil around the plants should be soaked with Bordeaux mixture. This should be done in spring before growth begins and later both the soil and the leaves should be sprayed and the growth of the disease checked in the beginning. We have several Delphinium plants which are infected with Leaf Spot and we are trying several preventions. Spraying and dusting with Bordeaux mixture may be a preventative but it is certainly not a cure, for the spots appear again on the leaves after several dustings. Some of the plants and the surrounding soil were treated with a solution of three different strengths of permanganate of potash. The strongest solution was i oz. of potassium permanganate crystals dissolved in 250 cubic centimeters of water. This concentrated solution was mixed with an equal proportion of water and the plants were, and are, being sprayed every ten days with 250 cubic centimeters of solution. The surrounding soil is stirred and also soaked with the solution. Formaline solution is also being tried as a spray and it is surprising to notice that the plants have survived this drastic treatment. Formaldehyde, as you prob' ably already know, is supposed to kill all living protoplasm, both in animal and vegetable cells, so we have hopes that the disease may, at least in some way, be checked. The solution made was one cubic centimeter of 40 per cent, formaline to 288 cubic centimeters of water and the application was the same as the potassium permanganate solution but used once only in four weeks. Lysol spray has also been tried on our plants in the same way as the two pre ventatives already mentioned. We are now making many experiments with various solutions and hope, in time, to not only check but cure the disease. The soil in which both the seed is sown and the plants are grown, is being sterilized. At present we have not found a definite cure but we hope to do so in time and if so, we shall publish it in the next issue of “Wise Acres. To prevent any possibility of getting disease on our young seedlings, we are taking all the necessary precautions. The soil used for seed sowing and pricking out is well sterilized with formaldehyde solution and it is left for a few days to dry before using it. The beds which are being prepared to receive our next crop of Delphiniums are frequently sprayed with formaline solution, using it twice as strong as before mentioned. We can only hope by using all these precautions to grow good, healthy Delphiniums free from the troublesome disease of Leaf Spot. The varieties of Delphiniums are all beautiful, and 1 should, indeed, hesitate, if asked to say which variety I liked best. The mauve ones may not appeal to some of us as much as the clear blues, but when wandering through a perennial garden, gay with many flowers, picking a few flowers here and there, one finds it extremely difficult to resist picking even the mauve ones as they look up with their dark brown, yellow, or white eyes and invite me to add them to my bouquet. Twenty-eight