Springtime brings numerous pests and diseases to flowers, with the most severe damage occurring in April and May. Common spring pests and diseases include powdery mildew, rust, black spot, leaf curl, and chlorosis, as well as pests such as longhorn beetles, aphids, scale insects, and scarab beetles. 



General methods for controlling flower pests and diseases include :
1. Maintaining a clean and hygienic environment in the planting area can reduce damage.
2. Protecting plants from damage and bark breakage to prevent pathogen invasion.
3. Pre-sterilizing the growing environment to kill pathogens and pests.
4. Strengthening daily management, maintaining proper water and fertilizer, good air circulation, suitable temperature, and adequate light to promote robust plant growth and control the breeding and spread of pests and diseases.



Specific control measures for related pests are as follows:
I. Aphids
Aphids (plant lice) are common in plants such as hibiscus, peach blossoms, roses, and honeysuckle. As temperatures rise, aphid populations increase, necessitating control measures. Control methods: 1. Spray with a 1200-1500 times dilution of 40% dimethoate or 50% phosmet in water. 2. For a small number of potted plants, spray with a 70-100 times dilution of neutral laundry detergent. 

II. Spider
Mites Spider mites begin to appear and damage jasmine, hibiscus, asparagus fern, rose, dahlia, etc., from early April. Control methods: For a small number of potted plants, frequently rinse the front and back of the leaves with tap water, or spray or dip them in a 100-150 times dilution of boiled and cooled flour paste. Rinse again with clean water after one or two days for noticeable results. 



III. Scale
Insects Scale insects (flower lice) on magnolia, rose, boxwood, and pittosporum begin to hatch from mid-April to mid-to-late May. Control methods: 1. Gently brush off the insects manually before hatching. 2. Check frequently, and spray with a 1000-1500 times dilution of 40% dimethoate during the larval hatching period. 

IV. Damping-off
Disease Damping-off disease is highly susceptible to occur in newly sown flowers, seedlings, and some plants prone to root rot when the temperature reaches 20℃ and the soil moisture is high. Control methods: 1. Before sowing, mix 1.5-4 kg of 70% pentachloronitrobenzene evenly into the soil per acre. 2. Control watering during the seedling stage to avoid overwatering. 3. When diseased seedlings are first discovered, irrigate with 1% ferrous sulfate or 200-400 times diluted 50% mancozeb solution, applying 2-4 kg of solution per square meter. 



V. Rust
Disease Rust disease in begonias easily infects flowering plants after rain in April and May, while rose rust infects when rose buds are about to open. Control methods: 1. When roses sprout, promptly remove and burn the first yellow diseased buds to eliminate the source of infection. 2. Spray with 15% triadimefon at a dilution of 700-1000 times during the initial infection stage. 

VI. Powdery
Mildew Powdery mildew in roses, impatiens, and smoke trees mostly occurs in May and June, easily causing symptoms such as yellowing leaves, withered leaves, and bent young shoots in summer. Control methods: 1. Ensure good ventilation and light penetration for the plants. 2. Apply less nitrogen fertilizer and more phosphorus and potassium fertilizer. 3. Spray once with a 15% solution of carbendazim at a dilution of 700-1000 times during the initial infection stage.