The oaks with small development

There are 600 varieties of oaks in the world (130 are cultivated in the nursery).

The originality of this genus is its diversity: there are oaks with willow leaves, oaks with chestnut leaves, ... Some of them have a large development; they will live 500 years, 1000 years and can reach 40 meters high. Others are of small development. With a long life expectancy of 300 to 400 years, the smallest of these oaks will reach 2.50 m and the largest 5-6 m; they are ideal for small gardens.

The Quercus bivoniana, the olive leaf oak. It can reach 8 to 12 meters depending on the soil and climate. It is a very useful oak to make a visual screen (hedge) in case of opposite because, on the one hand, it has an evergreen foliage (its thinness gives it an air of olive leaf) and, on the other hand, it can be led in vines (not only in high-stem), by keeping the branches at the base of the trunk. In this configuration, the plantation is made every 2,50 m between feet, and a pruning is made every year so that the trees are very well furnished.

It is possible to choose its rootstock according to the soil that will receive it: calcareous, wet or dry.

Its acorn is very decorative: larger than that of the common oak, its cup looks like a flower with many petals.

Quercus alba 'Longigemma', an American white oak. It is an oak that can reach a height of 15 to 20 m. In spring its young shoots are reddish pink, and turn green during the summer. In the fall, the foliage takes on beautiful autumn colors, wine lees. The leaves dry but remain in the tree (marcescent tree). It is also a grafted tree that can adapt to many types of land.

Note: not all oaks produce acorns, so grafting is used as a method of reproduction.

Ornamental bark dogwoods

They brighten up the winter with their bright or flamboyant stems. The dogwoods with remarkable bark are very graphic subjects, especially on a white snowy coat.

Very easy to grow and hardy, they will be your charming asset in the garden during the bad season.

Decorative bark dogwoods

Decorative bark dogwoods are very valuable in the garden in winter because they unfurl their red or orange stems throughout the bad season, brightening up the decor and contrasting with the surrounding greyness. They can be used as decorative hedges, borders, beds, or even as an isolated subject.

The white dogwood (Cornus alba) is a shrub native to Siberia, China and Korea that can reach up to 3 m in height and spread. Its upright habit is very graphic especially when the young shoots without leaves turn red/orange in winter. The variety 'Sibirica' is particularly interesting for its foliage that turns purple in autumn and for its bright red stems.

Kesselringii' has almost black, slightly purple shoots.

Those who like variegated foliage will be interested in the varieties 'Elegantissima' with grey/green leaves edged with white or 'Gouchaultii' with leaves edged with yellow and shaded with pink. On these cultivars, the bark remains very ornamental with a beautiful red color.

The female dogwood (Cornus sanguinea) is a shrub native to Europe with an upright and bushy habit.  It does not exceed 3m in height for 2,5m of spread. The typical species has green stems turning red in autumn if the plant is exposed to the sun, otherwise the stems remain green. The variety 'Winter Flame' is very ornamental with its orange-yellow stems, very bright in the garden in winter. This deciduous shrub is particularly beautiful in autumn when its leaves turn a blazing red.

The dogwood (Cornus stolonifera) is a shrub with a wide spread (4m) thanks to its suckering runners. Its dark red shoots are sumptuous in winter. The variety 'Flaviramea' offers the spectacle of its bright green to yellowish stems for a very bright effect in the garden.

Maintenance of decorative bark dogwoods

Decorative bark dogwoods become much brighter in full sun. Always plant them with good exposure. Not very difficult, these dogwoods accept most soils.

The young shoots being much more colorful than the old ones, the species cultivated for the color of their bark should be pruned each year in spring just before bud break. With sharp pruning shears, cut each stem flush with the ground above the second bud from the base. This will ensure that the young shoots are brightly colored in winter.

Japanese maples

The diversity of Japanese maples

The diversity of Japanese maples is reflected in the variety of leaf shapes, more or less cut (such as the Dissectum variety whose finely serrated leaves are very light) and changing colors (green, yellow, orange, red), different forms, upright, globe-shaped, or even drooping, and the variability of sizes: there are varieties of Japanese maple dwarfing that do not exceed 1 to 1.20 meters while others climb to 4, 5 or 6 meters high. But in any case, the Japanese maple remains a small tree.

Some remarkable varieties of Japanese maple

The maple Acer palmatum 'Aureum' is one of the most beautiful Japanese maples. Its foliage can have 4 different colors at the same time (normally pale lemon yellow in early spring, light green in summer and reddish orange in autumn).

Acer palmatum 'Asahi zuru' has a very original variegation pattern: it appears irregularly on the leaves, sometimes white, sometimes green.

Use of the Japanese maple in the garden

Japanese maples are perfect as isolated specimens but can be planted in groups to form a shrubbery, playing on different sizes and shapes: Acer palmatum Dissectum in the shape of a globe, Acer palmatum 'Orange Dream' with a bushy habit, Acer palmatum 'Senkaki' with bright red bark in autumn and winter...

We can also vary the colors by integrating varieties with red, yellow or variegated leaves.

Growing conditions of the Japanese maple

Japanese maples are always outdoor plants. Most of them appreciate a half-shaded or even shaded exposure - a maple planted in full sun will not look good - and sheltered from the wind.

They prefer acidic and fresh soils: in calcareous soils, bring them heather soil, then mulch them with, for example, bark which, in addition to preserving the freshness of the soil, contributes to its acidity.

Once planted in good conditions, Japanese maples develop without any worries.

Deciduous magnolias

Precious ornamental shrubs, magnolias are covered with splendid flowers from spring. Deciduous species are often much hardier than evergreens. Install them in your garden, you won't regret it!

Growing deciduous magnolias

Originally from Asia or North America, magnolias grow spontaneously in thickets or forests, not far from waterways. They therefore appreciate half-shade and a soil with an acidic tendency that remains cool in summer, although some species tolerate neutral soil. Very hardy, the majority of the varieties can be planted in all gardens without fear of frost.

Planting

The best time to plant your magnolia is in early fall, when the soil is still warm and the rains are abundant. This will give the root system time to form before the summer heat.

• Choose a location in partial shade and away from prevailing winds.
• Dig a hole that is wider than it is deep because roots tend to spread out on the surface, so the soil should be well loosened at this level.
• Add a good amount of decomposed compost to the soil removed from the hole and sand if it is compact and retains moisture. Magnolias like well-drained soil.
• Pour a bed of compost into the bottom of the hole and add a handful of ground horn powder.
• Remove your magnolia tree, taking care not to injure the roots. If necessary, cut out the container.
• Place the roots flat in the hole.
• Fill in the hole with the prepared mixture, packing the soil well around the trunk. The trunk should remain vertical.
• Make a basin to retain water at the foot of the shrub.
• Water very abundantly.

Maintenance

Remember to water recently planted trees often, even during the bad season if it does not rain. In summer, be careful! The soil should never dry out completely between waterings.

In autumn, spread a good layer of straw at the foot of young plants to protect them.

Remarkable species and varieties

The species with 'goblet' flowers (resembling tulips) are very popular in gardens. The many cultivars of Magnolia x soulangeana range from pure white with 'Alba superba' to very dark purple pink with 'Burgundy'.

Magnolia x liliflora 'Nigra' is a stunning cultivar with dark purple blooms.

Magnolia kobus, tolerates neutral to slightly alkaline soils, the white/cream flowers are sometimes tinged with pink at the base.

On the side of the magnolias with star flowers, we count the numerous varieties of Magnolia stellata of which 'Centennial' pure white, or 'Gold Star' with the amazing yellow. Magnolia x loebneri 'Leonard Messel' blooms in pale lilac starry clouds of the most beautiful effect.

Magnolias, growing tips

Early and late magnolias

The earliest magnolia varieties bloom during March and April, depending on the weather and spring temperatures, and their leaves develop after the flowers have bloomed. In contrast, the later varieties (which are still in bud in the spring) have their flowers blooming at the same time as the leaves. The later magnolias bloom in summer, during July and August.

Large and small magnolias

The smallest varieties of magnolias are between 2m and 2.5m tall, while the largest varieties can reach between 10 and 15m tall.

Unlike small-flowered magnolias, large-flowered magnolias are generally vigorous magnolias.

Growing conditions for magnolias

Magnolias are not difficult. There is no particular condition to respect when it comes to the nature of the soil, except that it is necessary to avoid too humid situations, with stagnant water. The species Magnolia kobus tolerates even limestone soils.

Pruning magnolias

Pruning magnolias is not mandatory, but it is possible to do one to clear and aerate the interior of the crown.

The origins of magnolias

Most magnolias come from China but some come from elsewhere, such as North America. The majority come from cold regions, although there are a few exceptions from warmer climates.

Diseases and pests of magnolias

Magnolias are not susceptible to diseases, nor to pests such as aphids or caterpillars. On the other hand, slugs can be very fond of flowers and leaves.

Propagation and varieties of spring magnolias

New varieties of magnolias are obtained from a selection of seeds. All magnolias have the possibility to hybridize with each other.

The different varieties can be distinguished by the color of their flowers which can go from pure white to very dark red.

• Black Tulip' : one of the darkest magnolias;
• Apollo' : pinkish purple flowers;
• Butterfly' : yellow flowers in April/May;
• Magnolia stellata chrysanthemiflora: small magnolia with light pink flowers with more than 40 petals, looking like chrysanthemums.

The mimosas

The arrival of mimosas in Europe

Mimosas were introduced in Europe, at the end of the 18th century, by the Anglo-Saxon explorer James COOK, who brought them back from Australia.

Mimosas were then naturalized in the south east of France, then in Brittany and in the south of England.

The cultivation area of the mimosa

The mimosa can be grown in the open ground, provided that the temperature does not fall below -10°C. Everywhere else, it can be grown in pots, as long as you have an unheated veranda, a cold greenhouse or a winter garden.

In the Paris region, in the gardens within the city walls, in the center of Paris, it is possible to consider growing a mimosa in the ground, if the exposure is full south and full sun, against a wall, in an urban area sheltered from the north wind. It should be noted that the hardiness of the mimosa is the same as that of the oleander.

Choosing a pot

The repotting of the mimosa is done in stages, from the small pot to the medium one, then to the large one. Under no circumstances should you repot your shrub directly into a large pot. This process is spread over 3 to 5 years.

Water requirements of the mimosa

The mimosa in a pot is very easy to grow, but it does not tolerate a lack of water. The same cannot be said for the mimosa in the ground. The mimosa behaves, then, like all plants that grow in dry soil. They can be found along roadsides, where they grow spontaneously, without watering or pruning.

How to prune the mimosa?

Grown in the ground, the mimosa is pruned only once a year, after flowering. There is no need to hoe, fertilize or treat it.

Grown in a pot, a soft pruning is enough. It consists in removing the faded flowers and keeping a harmonious ball shape.

The diversity of mimosas

The diversity of the mimosa's leaves is worth taking an interest in, on the one hand because it offers different shades of gray, silver, purple or green, and on the other hand, because 10 months out of 12, we only enjoy the foliage.

The flowerings, all spectacular, have multiple tones of yellow, white or orange, and very nuanced perfumes. Depending on the variety, we can have mimosas in bloom almost all year long (in summer, in autumn or in winter).

The forms are also diverse and varied: ground cover, small shrubs or large trees (30 meters high in Australia; 15 meters in Europe). Mimosas can therefore be used as an isolated subject, integrated into a bed or within a hedge, especially since they grow very quickly (they can triple in size every year).

Why graft mimosas ?

• To support all types of soil (clay, limestone...);
• To have a flowering from the first year;
• to avoid having invasive shoots.

They are grafted on mimosas of the four seasons because the latter support limestone, do not suckers, and have a root system not very extensive, which allows their installation against a wall.