genus that includes 100-150 species of shrubs or small deciduous trees, native to Europe, northern Africa, Asia and North America; C. monogyna and C. oxiacantha are generally grown as bonsai, as well as cultivars with flowers with decorative shades. It has vigorous but rather slow growth; the stem is erect, very branched and the crown tends to be rounded or pyramidal; the bark is brown-orange, cracked and flaky in some years old specimens. The leaves are bright green, paler on the underside, have a lobed margin, with 3-5 slightly pronounced lobes. Plants of at least 10-15 years old in spring produce very numerous small flowers with five round petals, white or pink in color, gathered in terminal inflorescences; in autumn the flowers give way to small, round, red drupes, which remain on the plant until the end of winter, containing a single seed. This plant is very suitable for growing as a bonsai, as it is quite easy to grow, is resistant to adversity, has decorative flowers and leaves that naturally tend to be small in pot grown specimens. Hawthorn is not very suitable for beginners, as the branches and the foliage must be very disciplined to have a harmonious bonsai.

Pruning: the most vigorous pruning is done after flowering or at the beginning of winter. Throughout the growing season, from March to October, it is possible to pinch the young branches, leaving 2-3 leaves; if desired, it is also possible to let the new branches grow and vigorously trim them in June. The metal wire is applied from March to September; the new branches tend to grow upwards, it is therefore good to intervene early with the metal wire to conform the foliage well.

Exposure: place the hawthorn in a sunny or partial shade. In the months of July and August it is good to shade the foliage, to avoid excessive heat; it does not fear the cold, therefore it does not need protection in winter. Watering: from March to September water regularly and abundantly, every 2-3 days; in the summer months, intensify watering, avoiding leaving the soil dry for long periods of time. In winter, water about once a week. In the vegetative period, fertilize the plant every 10-15 days, providing a fertilizer rich in nitrogen in spring, phosphorus in autumn.

Soil: the crataegus prefers loose, rich and well-drained soils, use a mixture consisting of one part of peat, one part of sand and two parts of clay; this plant also develops without problems in garden soil mixed with a small part of sand or incoherent material, to improve drainage. Repot the young plants every year, at the end of winter; the adult specimens are repotted every 2-3 years.

Pests and diseases: the crataegus particularly suffers from the attack of rust and powdery mildew; sometimes the aphids ruin the inflorescences.