Dahlias
Dahlias are a thermophilic culture, their native land is Mexico. Grown in abundance in the gardens. Appreciate for.brightness of color, abundant flowering, diversity and beauty of the shape of the inflorescence. Love the moisture and light. The above-ground part perishes at the slightest frost.
The drawbacks of dahlias are short-term preservation in cutting, poor colorability, lack of flavor, and the difficulty of winter storage.
Inflorescences of the dahlia are a basket, the sizes of which vary in diameter from 4-5 to 30 centimeters.
In the shape of the inflorescences are distinguished such groups of dahlias:
Decorative - large inflorescences with wide tongues of flowers.
Cactus - petals are folded into a narrow long tube, pointed, and sometimes dissected at the end.
Chrysanthemum - the most elegant group. Inflorescences resemble chrysanthemums. The petals of the inflorescence are twisted into a thin curved tubule. Pretty striking in the cut.
Spherical and pomponnye - petalled flowers collected in the expanding upward
drums. Inflorescences in shape resemble balls. Diameter of globular dahlias up to 20, lomontic - no more than 5 centimeters. Pompomial dahlias are the most resistant in cutting.
Non-masonry - are known in floriculture under the name of annuals, or Mignon. They are short and used in landscaping.
Anemone - with two rows of petal flowers, resemble an anemone in shape. Sometimes used in bouquets.
Bouquets and compositions of dahlias, although short-lived, but elegant and with a skillful selection of varieties are beautiful.
Varied terry dahlias are multiplied by dividing tubers and green cuttings, non-seed - seeds..
The division of tubers is a simple, but unproductive way. It must be combined with propagation by cuttings. The tubers stored in the beginning of April are brought into the premises or a greenhouse for germination, they are looked through, the rotted leaves are disinfected, the solution is disinfected with potassium permanganate solution( 0.5-1%), and placed in shelves, pots or boxes filled with sawdust, at a room temperature of 15-20FROM.In a few days, when the eyes are well-marked and reach a size of 1-2 centimeters, begin dividing the tubers, sprinkling fresh sections of coal powder. The divided parts are again planted, but already in nutritious soil. At the first opportunity they are taken to the greenhouses. The ground is planted after the danger of frost passes - in late May - early June.
You can plant tubers even without sprouting in the first half of May, but with the appearance of sprouts in case of danger of frosts, they will have to be covered.
Reproduction by cuttings is the most effective method of vegetative reproduction of dahlias. It promotes the rejuvenation of plants, while the constant multiplication by fission of tubers can lead to degeneration.
Plants obtained from cuttings in the first year blossom well, not inferior in quality and flowering time to plants grown from tubers.
Tubers, selected for propagation, in the beginning-marta are introduced into the greenhouse. Here they are planted in sawdust, peat, moss, sand so that the root neck is open to cut cuttings. The first time the tubers are kept at a temperature of 20-25 °, after the onset of growth, the temperature is reduced to 14-15 °, the watering is somewhat reduced.
Cut the cuttings when they reach a length of 6-8 centimeters. A sharp razor or knife is made with a cut. . under the bottom node of the leaves or cut the stem "with a lament".
For rooting cuttings are planted in prepared land directly on the rack, in boxes or cups. Usually the sod land, covered with a two-three-centimeter layer of washed sand, reduces the risk of decay. With insufficient humidity of air in the greenhouse cuttings are covered with a film or special frames. For better rootability, treat with heteroaukine, immersing their ends for three to four hours in a 0.01% solution( 100 mg per liter of water) or dipping into a powder mixture of talc( 100 grams) and heteroaucine( 100 mg).Well-rooted cuttings are planted in clay jars with a diameter of 7-9 centimeters and are placed in the penumbra for two or three days. The land in the banks should be nutritious, with humus. At the first opportunity carried out in greenhouses.
In late May - early June, plants are planted in the ground, carefully removing from cans. Blossomed cherry dahlias in July and form small tubers by autumn. The distance at landing should be 50-100 centimeters. The pit for planting is filled with nutrient soil mixed with humus. In the hole next to the tubers or cuttings set pegs up to a meter in height, to which, as the plants are tied up the plants. After planting abundantly watered and mulched.
In the future, watered regularly and abundantly, sometimes combining with irrigation and fertilizing. Feed once every two to three weeks with one of these solutions: 1) bird droppings 0.5 kg per 3 liters of water( well add 2-3 kg of furnace black).Then 2 liters of the infusion is dissolved in 10 liters of water. One bucket for 7--8 plants;2) mineral fertilizers 30-50 grams per bucket of water;3) slurry or mullein, diluted 10-20 times. From the second half of August, top dressing is stopped, watering, if necessary, continues.
As the shoots grow from the bottom of the planted tuber, the weakest of them are removed, leaving one or three shoots, from which the bush is formed. Stephens shoots, developed from the sinuses of leaves, are removed, since they delay the onset of flowering and reduce the size of the inflorescences.
With a large number of buds on the main stem, the extra ones are removed to get full flower buds. In this case, sometimes remove the middle bud, although strong, but having a short flower stem. For better rootability of the root neck, shoots and leaves are removed from the lower part of the shoot.
With approaching danger of frosts, dahlias are plowed with earth by 15-20 centimeters, but do so carefully so as not to damage the tubers.
Dig up the tubers after frosts that killed the leaves, shovel or pitchfork, pre-cut the above-ground part up to 15 centimeters with a sharp pruner and attach varietal labels to them. A blind shake off the ground, put into the room to dry.
Before storing the tubers, disinfect in a solution of potassium permanganate( 1 gram per liter of water) or in a lime solution( 200 grams per liter of water) for 15-20 minutes.
Good results are achieved by the waxing of tubers, which consists in the following: in the liquid paraffin heated up to the liquid state, the disinfected and dried tubers are lowered, they are quickly removed and, after curing in the air, the paraffin film is deposited.
Store tubers in the basement at a temperature of 3-5 ° C and 50-60% relative humidity. You can not store the tubers in a wet cellar-The storage is pre-disinfected with sulfur fumigation( 50 grams of sulfur per 1 sq. Meter), and whitewash with freshly lime.
Put tubers on racks or boxes in sawdust, wood, peat, vermiculite or charcoal. Paraffined tubers do not fall asleep. During storage, the tubers are periodically( at least once a month) browsed, removing the decayed.
Pests and diseases are relatively rare in dahlias. The most common spider mite, causing the appearance on the leaves of the smallest light spots, merging with a strong lesion. On the underside of the leaves a thin cobweb appears. Control measures - dusting with sulfur powder.
Wet summer sometimes causes the appearance of a large number of slugs, for the control of which the soil around the plants is sprinkled with lime or superphosphate, they are collected by hand.
The most dangerous disease is dahlia - a viral mosaic. On leaves there are light green blurry spots of various shapes and sizes. Over time, plants become dwarfish and ugly, blooming badly. Dark cracks appear on the upper part. Control measures - removal of sick plants, heating of tubers in water with a temperature of 50 ° C for 30 minutes or air heating at 35 ° C - five days.
When powdery mildew appears on leaves, sprayed with Bordeaux liquid or pollinated with sulfur.
The assortment of dahlias is extremely large, varied and unstable. Annually a large number of new varieties appear, which replace the old ones. Therefore, it is difficult, almost impossible, to give a stable list of the best recommended varieties. Table 5 gives a brief description of some of the best varieties from the list of foreign and domestic breeding).