Generative reproduction
Species are multiplied by sowing seeds. The seeds collected in autumn are kept dry in a cool place until spring, and sown from March to May. The seeds of ginkgo, juniper, yew and huchen are covered with a fleshy parchment, which is removed immediately after harvesting so that the seeds do not lose their germination.
In some species, seeds require stratification before sowing. It is a process of storing seeds at low temperature (-4 ° C) in a moist substrate, e.g. sand, and at home, e.g. on the lowest shelf in a refrigerator, where we control the substrate so that it does not dry out. It is about creating similar conditions to the soil in winter. For example, ginkgo seeds require stratification for 15-18 months, Chinese juniper juniperus chinensis, common juniper J. Communis, virginian J. Wirginiana for 6-18 months, and in larch Lariz sp., White pine pinus strobus, small flowered pine P. Parviflora and most of the spruce picea sp. stratification takes about a month. We sow the prepared seeds when the first small sprouts appear. Therefore, stratification must be started early enough so that sowing occurs in the spring period.
Seeds can be sown directly into the ground, in boxes, small plastic pots or pressed peat discs, which swell when watered.Sowing into containers reduces the shock of transplanting and contributes to a much faster growth of the root system. Especially large seeds - limbs, ginkgo - should be sown in flower pots. Small seeds, e.g. of cypress and thuja, are sown in a broadcast. Regardless of the type of container, they are placed at a depth twice the thickness of the seeds. The sowing substrate should be humus, airy, e.g. peat and sand 1: 1 or 2: 1, with a pH of 5.0-5.5. Cover the sown seeds with a thin layer of coarse sand and cover with foil or glass.
The seedlings of coniferous plants are susceptible to fungal diseases, therefore it is impossible to allow excess moisture, which promotes the growth of fungi. Sowing must be aired frequently. In the first year, the seedlings should be protected for the winter by placing the containers, eg under the inspection. In the second year, in spring or autumn, after the end of plant growth, we dive, and in the next year we plant out a permanent place.
Vegetative reproduction
Plants propagated from seeds generally do not pass their traits to their offspring. From cuttings easily and fairly quickly (about 3 months) root: common juniper, pea cypress and lawsona, thuja. Rooting of virginia juniper, Nutcaya cypress, blue spruce and fir trees is difficult and long-lasting. The best time for planting is from mid-August to the end of September, when sufficient woody seedlings can be obtained. For cuttings, we choose side shoots (in columnar yew varieties, top shoots), which grew in good sunlight. By tearing this year's growth away from the older shoot, we leave some wood at the end of the twig, this is the so-called heel and a thin fragment of the cortex - the tab, which we shorten. The heel must not be damaged, because this part is the first to grow roots.
Common juniper seedlings do not need to have a heel, they are cut anywhere in this year's growth. The length of the seedlings is approx.10 cm, and in dwarf varieties about 3-5 cm. The same substrate is used for rooting as for sowing, i.e. sand with sifted peat 1: 2 or 1: 3. The rooting process accelerates the application of rooting agents that contain plant hormones. Dip the seedling in loose rooting plant to a depth of 0.5-1 cm and place it strictly in the substrate to a depth of about 2-3 cm so that it does not touch each other. You can plant in pots, boxes or small glazed multipliers with a heated bottom.
The temperature of the substrate should be 16 ° C, and the air temperature - 12-15 ° C. In January, the temperature is lowered: the substrate to 8-10 ° C, and the air temperature to 5-6 ° C. Beginning in mid-March, cuttings begin to take root. We cover the containers with the seedlings with foil or glass, but do not allow excessive humidity or drying. From mid-May, rooted cuttings can be pierced into larger pots, and after 1-2 years they can be planted permanently.
