Detailed Explanation of Key Techniques for Summer Care of Flowers and Potted Landscapes

Summer is hot and rainy, a peak growing season for some flowers and a dormant period for others. To help flowers make it through this stage smoothly, management should be strengthened in areas such as watering, shading, and pest and disease control.

First, summer temperatures are high and water evaporates quickly, so watering should be done more often each day, such as once in the morning and once in the evening. At the same time, during hot seasons, aside from vigorously growing flowers such as jasmine and Chinese rose, fertilization is generally not advisable, especially for rhododendrons entering semi-dormancy and dormant bulbous flowers such as cyclamen and freesia.

Second, for some semi-shade and shade-loving flowers, high temperatures and direct sunlight must be strictly avoided in summer. Shading measures should be taken, and water should be sprayed to lower the temperature. Even for extremely drought-tolerant plants such as cacti, when the temperature exceeds 38°C, there is still a risk of scorching. For rhododendrons, in addition to daily watering, water should also be sprayed on the leaves and the ground to maintain moisture and lower the temperature. However, summer often brings heavy rainstorms. After water accumulates in the potting soil, nutrients are easily lost, so after rain the pot should be tilted to let the rainwater drain out.

Finally, the muggy summer is also a season with a high incidence of pests and diseases. Diseased branches and leaves should be removed promptly, supplemented by chemical control. For example, Chinese rose is prone to black spot and powdery mildew in summer; the former is treated with Bordeaux mixture and the latter with carbendazim, sprayed once every half month. Orchids are prone to anthracnose during the plum rain and high-temperature seasons; besides improving ventilation and light conditions, when disease occurs, thiophanate can be sprayed once every 10 days.

In summer, potted flowers have vigorous respiration and require good air permeability in the potting soil. Therefore, when the potting soil is not dry, generally do not water, so as to avoid excessive water affecting air permeability, but once it is dry, water immediately and water thoroughly. In summer, potting soil often cracks due to excessive drying, so watering cannot be done all at once; otherwise the water will leak straight down through the cracks to the bottom of the pot while most of the potting soil remains very dry. After the first watering, wait a moment, and water again once the soil cracks have closed.

If you forget to water for several days, causing the plant to become drought-stressed and wilted, do not rush to pour a large amount of water. First move the potted flower to a cool, ventilated place, use a spray bottle to spray the leaves 2 to 3 times, and after the leaves recover, water a small amount, and once the root system regains its water-absorbing function, water thoroughly. Water cautiously in midsummer and deep winter.

Water temperature has a direct effect on the physiological activity of flower roots. If the water temperature and soil temperature differ greatly (more than 5°C), watering will cause a sudden change in soil temperature that harms the roots, instead affecting the roots' absorption of water and causing physiological drought. Therefore, it is better to water when the water temperature is close to the soil temperature, and this deserves even more attention in winter and summer. In winter, it is best to first store the water indoors for a period, or add a little warm water, to raise the water temperature to 15 to 20°C before watering. In summer, watering should be avoided under blazing sun and during the high temperatures at noon.