The复兴of Bulbous Flowers in Autumn Planting
If you want to understand the experience of bulbous flowers, this article on the rejuvenation of autumn planting bulbous flowers will be introduced by the editor.
Generally, in horticulture, bulbous flowers are divided into spring planting and autumn planting according to the planting time. Before planting bulbous flowers, it is necessary to first distinguish their temperature requirements, that is, to know whether they are spring or autumn planting bulbs.
Spring bulbs such as Hippeastrum and Hemerocallis require higher temperatures during the growing period, so they are planted in spring, bloom in spring and summer, and enter dormancy as the temperature drops in winter. In the northern part of China, where the winter is cold and the temperature is often below minus 5 degrees or even lower, the bulbs in the ground cannot resist such low temperatures and need to be dug out and stored properly to overwinter. Autumn planting bulbous flowers such as tulips and hyacinths are cold-resistant and afraid of heat. They are planted in autumn, grow rapidly when the temperature rises in early spring of the following year, bloom in spring, and the aboveground parts wither when the temperature is high in summer, and the bulbs enter dormancy in the ground. If the planting time of these two types is mixed up, it will inevitably lead to cultivation failure.
Commonly cultivated autumn bulbs include tulips, hyacinths, narcissus, snowdrops, iris, freesias, tiger eye lilies, saffron, and grape hyacinths. Lilies are special, although they also belong to autumn planting bulbs, but the source is too complex, mainly including Asian lilies, oriental lilies, and various hybrid lilies. These different lilies have great differences in habits, and many lily varieties only bloom in summer under natural conditions, which is very different from other autumn planting bulbs, so they are not discussed together.
In home planting, various reasons often lead to the degeneration of bulbs, causing the bulbs to fail to bloom the following year or to shrink year by year, losing their planting value. To rejuvenate the bulbs, it is first necessary to understand the various causes of bulb degeneration and start from this to find ways and means to solve the problem. Next, let’s analyze these common problems and causes one by one and look for corresponding countermeasures.
1. Close planting
In potted plants, in order to pursue beauty, bulbs are often planted in very small containers or closely planted. We know that commercial bulbs are originally grown in fields, with deep and long roots, especially the narcissus and snowdrops of the Amaryllidaceae family and the hyacinths of the Liliaceae family, all of which have long and developed root systems. If they are forced to plant them in small containers, as long as the bulb is large enough, the bulb can consume its own nutrients to produce good flowers. In such cases, if it is intended to be a one-time cultivation from the beginning, the bulbs can be discarded after flowering. But many flower lovers hope to have them bloom year after year. If this is the plan, it is necessary to choose a spacious and comfortable container for the bulbs so that their roots can stretch out. It is proportional to plant a single bulb in a large and deep pot, so it is better to choose a large pot for group planting. For example, narcissus with a bulb circumference of about 14 cm can be planted with 4-5 bulbs in a pot with a diameter of 25 cm and a depth of not less than 20 cm. Larger containers have smaller temperature changes in the soil, which is beneficial for bulbs that are particularly sensitive to temperature, such as tulips and saffron, to extend the growing period of the bulbs and provide necessary time for accumulating more nutrients. When the volume of the container is large enough, it can approach the effect of ground planting. Generally speaking, planting in large containers is more beneficial for rejuvenation than in small containers, and planting in large containers with one size larger than in small containers with one size smaller is more beneficial for rejuvenation, and ground planting is more beneficial for rejuvenation than potted planting.
2. Hydroponics
This is a pure one-time cultivation method from the beginning, so don’t have the idea of rejuvenation. If you really can’t bear to discard them after flowering, just find a piece of land to plant them!
3. Time and temperature
We know that autumn planting bulbs generally have a vernalization process, that is, rooting at low temperature (2-10 degrees) to break dormancy. This process usually lasts for 2-4 months. But the habits of various autumn planting bulbs are not the same, so the planting time should be determined by choosing the corresponding weather temperature. In the middle and lower reaches of the Yangtze River, the temperature drops to about 20-24 degrees Celsius around the Mid-Autumn Festival in September, and the roots of Fritillaria, grape hyacinths, and freesias become active first. These three can be planted from the end of September to the end of September in the middle and lower reaches of the Yangtze River. At the time of the autumnal equinox in the last ten days of September, when the temperature drops to 18-20 degrees Celsius, the roots of narcissus, snowdrops, and iris also revive, so they must be planted from the beginning of October to mid-October. In the second ten days of October, when the temperature is below 18 degrees, plant hyacinths, tiger eye lilies, and saffron. At the beginning of November, when the temperature is below 15 degrees, plant tulips. Here, we need to pay special attention to the fact that due to the large climatic differences between the north and south of China, the planting time should follow the local weather forecast and determine the corresponding time instead of following the bookish statements.
4. Root system and planting depth
For autumn planting bulbs, the formation of the root system is one-time, and once damaged, it cannot be repaired. Therefore, when planting, it is necessary to plant it once and avoid transplanting. In terms of planting depth, due to the limitations of potted conditions, it is impossible to plant too deep. Generally, according to the size of the bulb, hyacinths, narcissus, and snowdrops can cover the soil to the bud at the top of the bulb, with the top bud slightly exposed above the soil; tiger eye lilies, saffron, and grape hyacinths are small in size, and the soil should be covered with 2-3 cm; iris, tulips, and freesias are tall and thin, and it is better to cover the soil with 5 cm. If planted in the ground, hyacinths, narcissus, and snowdrops should be covered with 5 cm of soil, and iris, tulips, and freesias should be covered with 10 cm of soil.
5. Natural bulbs and forced cultivation
Because autumn planting bulbs have the characteristic of breaking dormancy at low temperature, they can quickly germinate and bloom by artificial cold storage for a period of time without the need for natural low-temperature accumulation. This method is forced cultivation. Conversely, bulbs that break dormancy through natural seasonal low-temperature accumulation are called natural bulbs. Forced cultivation mimics natural low temperature. For professional cultivation, bulbs are planted immediately after cold storage and provided with suitable temperatures on a large scale. This is impossible for ordinary horticulture enthusiasts, and moreover, from the cold storage to the retail and then to the consumer's hands, the bulbs will experience another temperature change and may encounter high temperatures. At this time, some bulbs have already begun to root and may be injured. Therefore, we should try to buy natural bulbs, which is more secure. In addition, low temperature has some other effects on bulbs: narcissus, snowdrops, grape hyacinths, and saffron, low-temperature treatment will make their plant shape compact and dwarf.
6. Water and soil texture
Autumn planting bulbs prefer loose and breathable, well-drained, low-salt, and neutral soils. It is recommended to use decomposed leaf soil for planting. When planting bulbs, be sure to prevent waterlogging, especially for friends who like to use trays for potted plants. Keep the trays dry and do not let water accumulate in them, as this will not only make the pot too wet and unbreathable but also cause diseases. The choice of pots should also focus on breathable purple sand and ceramic pots, and the bottom of plastic pots should have enough and large holes. Porcelain pots should generally not be used.
7. Light and humidity
The original ecological state of autumn planting bulbs is often growing under the sparse shade of tall deciduous trees. Imitating this state of light change and humidity is our direction. When autumn and winter come, the leaves of trees fall, and the sunny spots in the forest become bright, so abundant sunlight should be given to autumn planting bulbs during this period. At this time, the fallen leaves will play the role of keeping warm and moisturizing. When spring comes, the bulbs growing underground will germinate and bloom before the leaves of the trees sprout. In April, when the forest shade of the trees is gradually visible, the flowers of the bulbs have already begun to wither. The forest shade of the trees provides a cool small environment for the bulbs. Therefore, in the artificial cultivation of this stage, we should also provide a cool small environment for the bulbs, with bright light but not direct sunlight.
8. Fertilizer and nutrients
Bulbs generally prefer potassium fertilizer, but during the rooting period, a certain amount of nitrogen fertilizer is needed, and the decomposed leaf soil itself contains less nitrogen fertilizer. Therefore, it is more appropriate to choose sulfate potassium compound granular fertilizer as the base fertilizer. Two points need attention: the amount should not be too much, especially in potted plants, less is better than more, generally within 10 grams in a 25 cm pot, and avoid direct contact with the bulb when applying, and bury it in the pot. Another point is that when buying fertilizer, do not be greedy for cheap, buy from regular merchants, and be sure to make sure it does not contain chlorine-containing fertilizers such as potassium chloride. Bulb plants, especially Liliaceae plants, are allergic to chlorine and easily poisoned. Once poisoning is discovered, it is generally too late and will die. This point must be taken seriously. After germination, apply 0.1% urea + 0.1% potassium dihydrogen phosphate solution every 2 weeks, stop urea during flowering, and apply potassium dihydrogen phosphate and boron-zinc complex fertilizer after flowering, which is beneficial for the accumulation of sugar in bulbs. Similarly, when applying fertilizer, apply thin and sparse fertilizer every 2 weeks.
9. Diseases and pests
Common diseases such as gray mold, root rot, soft rot, and flower spot have different causes, mainly from fungi, bacteria, and viruses. Generally, bacterial soft rot is highly contagious and is a major disease of hyacinths and iris. Flower spot is a viral disease and basically incurable. Therefore, the disease is mainly prevented, and once it occurs, there is basically no way to deal with it. Disease prevention and control must do the following: (1) The soil should not be too wet, as running water and rain can be carriers of the pathogen; (2) strict soil and bulb disinfection; (3) avoid consecutive cropping, and the potting soil should not be reused; (4) avoid damage during digging and planting; (5) spray fungicides regularly, commonly used 50% carbendazim (prevent fungi) wettable powder 600 times or 75% chlorothalonil wettable powder 800 times spray; 75% agricultural streptomycin (prevent bacteria) 1000 times spray, generally every 2-3 weeks; (6) severely diseased plants should be promptly removed and incinerated, especially viral flower spot, immediately remove the diseased plants, and never tolerate, otherwise the virus will spread rapidly through pest insects.
Pest control: The presence of pests not only directly harms the plants but also transmits the disease. Common pests in autumn planting bulbs include aphids, snails, moths, and grubs. Control usually chooses 75% phoxim 1000 times liquid root irrigation or 40% omethoate 1000-1500 times spray.
10. Harvesting and storage
In early summer, when the aboveground part of the autumn planting bulb gradually dies, dig out the underground part carefully, wash it clean with running water, fully dry it in the shade, and then put it in a net bag and hang it in a ventilated and cool place for storage.
Generally, in home planting, the conditions for rejuvenation are insufficient, so if you want to rejuvenate, you should also try to choose stronger autumn planting bulb varieties and take good care of them. For example, narcissus, snowdrops, iris, and freesias. It is particularly worth noting that iris can overwinter outdoors in the south of the Yangtze River, and it germinates early, from the end of October to the end of May of the following year. It enters dormancy when it is especially cold in winter and has a long growing period, so it is relatively easy to rejuvenate at home. Tulips and saffron are too sensitive to temperature, and in years when summer comes early, they will produce many useless small bulbs, making rejuvenation very difficult.
Of course, if you have the conditions for ground planting, it is the best for rejuvenation, because the ground temperature changes little, warm in winter and cool in summer, and the bulb roots can stretch out, which are two conditions that potted plants cannot compare. If you further strengthen drainage, fertilization, disease control, and shading management in early summer, the rejuvenation of autumn planting bulbs will not be a big problem.
The above is a detailed introduction to the rejuvenation of autumn planting bulbous flowers. I hope it can help you. Don’t forget to check out more flowering experience and common sense!