Spiraea grefsheim is a shrub that is native to Asia. It is a popular plant in many gardens because of its showy flowers. The flowers are white with a pink center and they bloom in the summer.
Related plant:
Spiraea Bumalda Anthony Waterer
About soil condition, the Spiraea grefsheim prefers well-drained soils rich in organic matter. It is not particular about pH and tolerates both acidic and alkaline soils. It is quite tolerant of urban pollution and will even thrive in inner city environments. This plant does best in full sun to partial shade.
Just like other shrubs in the Spiraea genus, the Grefsheim requires full sun to partial sun in order to thrive. It's an adaptable plant, however, so it can also tolerate some shade. The shrub should be planted in an area that gets at least six hours of sun per day.
The temperature condition that is best for Spiraea grefsheim is a cool climate. They do not tolerate heat well and need a period of dormancy in order to flower properly. The ideal temperature range for them is between 45-55 degrees Fahrenheit.
Ideal humidity condition for this plant is 50% and above. However, it can tolerate lower humidity levels but may experience some leaf drop. The best way to increase the humidity for your plant is by setting it on a pebble tray or grouping it with other plants.
The fertilizer, usually the plant food, is essential to the growth of the plant. The roots are the part of the plant that anchors it to the ground and takes up water and nutrients from the soil. The root system also stores energy in the form of carbohydrates.
Pruning is an important part of caring for your spiraea grefsheim. Pruning not only keeps your plant looking its best, but also helps to encourage new growth. When pruning, be sure to remove any dead or diseased leaves and stems. You can prune spiraea grefsheim any time of year, but late winter or early spring is best.
Propagation of Spiraea grefsheim is best done by softwood cuttings. Cuttings should be taken from new growth in late spring or early summer. The cuttings should be 6-8 inches long and have at least 2-3 sets of leaves. Cuttings should be placed in a well-drained potting mix and kept moist until roots have formed.
Usually, the plant growth rate well in full sun, and they are very tolerant of poor soils. They will grow in partial shade, but their growth may be slower. They do best in moist, well-drained soils, but are quite tolerant of dry soils. Once established, they are quite drought tolerant.
Common problems for this kind of plant are powdery mildew, rust, and several types of leaf spot. These problems are typically caused by fungi and can be difficult to control. Prevention is the best method of control for these diseases. Make sure to plant spiraea grefsheim in an area with good air circulation and plenty of sunlight. Avoid overhead watering, which can promote fungal growth. If you do notice any of these problems on your plant, remove affected leaves and dispose of them. You can also try using a fungicide to control the problem.
Source:
Spirea, Mellow Yellow
Simply Spirea | Arnold Arboretum
FPS-558/FP558: Spiraea contoniensis Reeve's Spiraea, Bridal
