A hydrangea with blue flowers

You chose it for its beautiful deep blue color, but surprise, once installed in your garden for some time, your blue hydrangea has turned into pink. Did the fairies of 'Sleeping Beauty' come to you? No way! Let's see how to give it back its original colors.

Mysteries of Nature

Hydrangea macrophylla, better known as the florist's hydrangea, is a spectacular flowering plant, as much for the rounded size of its inflorescences as for its colors. Some varieties have a variable flower color passing strangely from blue to pink. There is no mystery behind this, it is simply a physical phenomenon that comes into play in the color of the flowers: the pH and the composition of the soil.

In a soil with an acidic tendency, the flowers remain blue or are purple if the variety chosen was it at the base.

In a calcareous soil with a pH higher than 7, the color turns spontaneously to pink, or even to red if the variety allows it.

Another parameter concerning the soil, the iron and aluminum content in their assimilable forms must be sufficient. Knowing that in calcareous soil, iron is very poorly assimilated by plants, everything is explained...

How to maintain the blue color in hydrangeas?

As we have seen, the color varies according to the pH of the soil. It is therefore obvious that it will be a little complicated to maintain a beautiful blue color in calcareous soil. However, here are a few ways to help:

• Apply a fertilizer rich in potash and alum in August when the future flower buds are forming to prepare for the next year's bloom.
• Apply every spring and during the growing season a bluing product.
• Be careful with tap water, which, if hard (calcareous) will not suit your hydrangea. Always prefer to water it with rainwater in these conditions.
• When planting, if the soil is chalky, dig a pit of 1 meter by 1 meter and fill it with heather soil, compost and a little dried blood before installing your hydrangea. Each fall, scratch some heather soil on the ground.
• If the soil is very calcareous, prefer planting in a large container in a mixture of heather soil.
• Mulch the base of your hydrangea with a thick mulch of pine bark. This mulch tends to slightly acidify the soil. If you are a fan of mineral mulch, don't hesitate to mulch the base with crushed slate, known to give a beautiful blue color to the hydrangea.
• You can find it in DIY stores or garden centers under the name 'Blueing Fertilizer for Hydrangeas' . These products contain iron sulfate and alumina, in addition to NPK formulations adapted to hydrangeas.
• Remember to water your hydrangeas regularly so that they do not suffer from water shock and so that the roots can synthesize the elements provided.

How to choose your bamboo?

To appreciate the quality of a healthy and vigorous bamboo, you should not only look at its aerial parts but also unpack it to discover its rhizomes.

If it is impossible to remove the pot, i.e. if it is swollen by the rhizomes or bursts under their push, this is the plant you need.

Once the pot is removed, we observe:

• Root system condition with the presence of rhizomes. It is the future of your plant which will give the future turions. Check that the roots and rhizomes are dense enough.
• A beautiful hair (assimilating roots) with beautiful root caps mainly in spring when there is a resumption of the vegetation. These rootlets will allow a good absorption of water and mineral salts. They can go down to several meters under ground.
• The bamboo can develop a bun, that is to say to make a spiralization of the roots. What is a handicap for many plants is not for bamboos. Once planted, it will not repeat this way of growing. It has developed a bun by constraint due to the pot. Once released, the rhizomes will resume their horizontal growth.
• Advice: at plantation, separate the rhizomes which spiral by distributing them in the ground.
• In summary, it is better to choose a bamboo with few culms but many rhizomes than the opposite. Vigorous rhizomes are more important than beautiful stems. The future of your bamboo depends on the reserves stored in its rhizomes.

The characteristics of a rhizome

• Horizontal underground stem
• Hollow and partitioned stem (fistulous rhizome)
• The nodes carry eyes that will develop into new culms.
• Roots adapted to the storage of energy reserves (starch) for its future growth. A well-fed and well-maintained bamboo the year before will give beautiful culms the following year.
• It fixes the plant to the ground with its adventitious roots. There are also docking roots that make the culms more resistant to wind.
• The rhizome is a potential propagule. From a section of rhizome one can obtain another plant (cloning)
• Although endowed with a positive geotropism, the tip of the rhizomes sometimes emerges from the ground to give a culm (positive phototropism). It can also be diverted from its trajectory (stone...), go out of the ground and then enter it again under the effect of its positive geotropism.

The questions that we must ask ourselves are the following

Different types of underground devices ?

A cespitose bamboo has pachymorphic rhizomes (from the Greek prefix meaning thick) .

The apical bud of the rhizome evolves in thatch. It doesn't go very far in the ground. In this case, the internodes are short and more or less swollen. Horizontal growth is done only on a few centimeters. Bamboos with these pachymorphic rhizomes form tight clumps. They do not spread on the surface.

A tracing bamboo has leptomorphic rhizomes (from the Greek, leptos=thin and morphos=shape), often with unlimited growth (monopodial). In this case, the internodes are long and thin. Their growth is horizontal.

Does the plant have a good root system?

The most important is in the substrate which is not in sight. It is the rhizomes that will ensure the future of your bamboo plant and not its culms.

Was the bamboo well fed last year?

Its rhizomes, which store reserves thanks to the photosynthesis of its foliage, not only allow the plant to be fixed to the ground but are also the carriers of future culms. The good work of the nurseryman is mainly found in the quality and the richness of the rhizomes. The good conditions of culture (heat in spring for a good exit of the shoots and in summer to facilitate the accumulation of the reserves in the rhizomes) make it possible to obtain a subject with well augusted shoots, resistant to the cold and rich rhizomes for the future of the plant.

Bamboos for all tastes

Bamboo has become an essential plant in our gardens. Fast growing, sometimes even invasive, this carefree plant comes in countless varieties, each with its own place in the garden. Giant, slender or bushy, dwarf or variegated, you will find the bamboo that suits you!

Ground Cover

Take advantage of the power of expansion of this plant to cover spaces where you want to eradicate weeds or create green areas without worrying about requiring only low maintenance. Indeed, the tracing roots and the density of the foliage will prevent the regrowth of weeds and will avoid you the always painful chore of weeding.

Choose the Sasa genus with its shiny and wide foliage which will do wonders in shady and humid areas. In dry and sunny soils, Pleioblastus is preferable as it can be pruned at will and will cover large areas very quickly.

Isolated subject

Always very elegant installed in a large pot, it will enhance a wooden terrace. Cultivated in a pot, the water and fertilizer must be constant to keep the brightness and beauty of the foliage and avoid its wilting. For this use Semiarundinaria fastuosa will give good results because it is not very tracing. Its culms rise very straight like candles erected towards the sky. In the sun it takes a beautiful amber color very characteristic. Very graceful, Phyllostachys decora resists well to dryness and will find its place on Mediterranean terraces.

Boundaries and borders

Bamboo, if well contained, can also be used to create borders, as well as to stabilize sloping ground. The genera Sasa, Shibataea or Pleioblastus lend themselves well to the creation of borders and the delimitation of paths as long as they are well contained with the help of anti-rhizome barriers. In early spring, prune them very short to induce the formation of new foliage and keep a compact habit.

Bamboo hedges

This is the most common use of bamboo. These hedges offer excellent visual, acoustic and wind protection, creating favorable microclimates for fragile plants.

Fargesias and Phyllostachys are most often used to create hedges. Beware, because if the conditions are right for them, their growth can be very fast, and they will easily reach 15 meters high. But don't panic, they can be pruned in height as well as in width!

Fargesia robusta 'Campbell', a non-tracking bamboo

What is a non-tracking bamboo ?

A non-tracking bamboo is a bamboo whose clump will thicken little by little, about 5 cm on each side, every year.

Most of them belong to the Fargesia family. Among them, Fargesia robusta 'Campbell', particularly requested by individuals and professionals.

The advantages of Fargesia robusta 'Campbell' bamboo

1. Its growth is relatively fast.
2. It can reach 3 to 5 meters high, depending on the growing conditions (soil quality, irrigation...), and its growth habit is erect, which allows it to be used to form a hedge, whereas other Fargesias, such as Fargesia rufa, have a much more open habit.
3. It tolerates full sun exposure, whereas many Fargesias will require a semi-shaded exposure or a cool soil with relatively mild temperatures, as in Normandy or Brittany.

How to grow Fargesia?

Fargesia will produce canes twice a year: a first important time, in the second part of spring, then a second time, more modestly, in the beginning of autumn.

Be careful: if the canes are very strong when they are out of the ground, they are very fragile when they emerge.

Fargesia accept most soils, not too sandy (too filtering), nor waterlogged in winter. They are greedy grasses that appreciate generous contributions of compost at planting. Then, we install an organic mulch (straw, RCW, small thickness of lawn clippings) in order to keep the soil fresh while letting the young canes grow. Woven fabric should be avoided because the canes have difficulty to pass through.

Once planted, bamboos require no maintenance and are pest free.

How far apart should bamboo be planted to make a hedge?

Knowing that the bamboos will eventually join together will depend on your patience. If you are in a hurry to get a compact hedge, plant every 20 to 30 cm. But if you have time, or if your budget is limited, you can space them one meter apart (then count on ten years for them to join).

The multiplication of bamboo

Bamboo multiplies by division, which explains its price, sometimes a bit high: the division takes time. Some bamboos are also multiplied 'in vitro'. But this can lead to a more compact habit and a smaller size in the first years.

Can Fargesia be grown in pots?

Be careful, Fargesia is not a very drought resistant bamboo. It is therefore necessary to be vigilant, especially since it does not show any particular signs when it is thirsty. In winter, if the water in the pot freezes, it can die of thirst.

Bamboo, a plant easy to live with

The bamboo plantation is a very old park built in 1956 by Eugène Mazel, known essentially for its bamboo, although it contains other types of vegetation. Native plants are found alongside exotic plants.

Bamboo, not so exotic as that!

Bamboos are often considered as exotic plants, although they grow very easily in different climates; and ours is no exception!

Bamboo, a perennial and evergreen plant

The great advantage of bamboo, and what makes it appreciated by gardeners, is that it stays green all year long (the foliage is evergreen). It is therefore a great pleasure to be able to enjoy this light and graceful foliage, this very lively and natural plant, every year in winter.

Bamboo, a plant for fresh ground, but not only...

Bamboo is best planted in fresh, deep and very draining soil. However, it can adapt quite well to more difficult soils. Of course, its growth will be slowed down compared to a culture in good conditions, but you can still enjoy its presence.

Bamboo, an invasive plant? Yes, but...

Bamboo is a plant that lives in colonies. As everyone knows, it sometimes tends to spread and become invasive. But don't panic: if you don't want it to spread, simply cut the young shoots in the spring. Another solution is to install an anti-rhizome barrier at the time of planting; this will limit the spread of the plant.

Trailing varieties and seedling varieties

The last possible option, to prevent bamboo from invading the entire garden, is to opt for non-tracking varieties of bamboo (yes, they do exist!): cepitant bamboos. Contrary to the tracing varieties that run, the cespitose varieties are varieties that grow in groups. You will thus obtain a beautiful clump of bamboo with stable dimensions.

In summary

Bamboo is a plant not to be afraid of, easy to live with, and always a pleasure to grow because of the production of new shoots every year.

The bamboos

The difference between tracing and non tracing bamboos, mainly fargesias, comes from the way they develop their rhizomes.

The tracing bamboos have their rhizomes growing horizontally in any direction while those of the fargesias grow in V, tightened at the base but splayed in height (like a bulb would).

The size of bamboos can vary from 2 to 5 m depending on the species.

Cultivation needs of bamboos

Bamboos appreciate an ordinary and not too heavy soil: the lighter the soil, the more the bamboos grow.

Contrary to what we think, they are not water plants. Watering is useful only when it is hot.

There are two types of fargesias: those that prefer shade and those that prefer sun. If you place sun bamboos in the shade, they will still grow. But if you place shade bamboos in full sun, they will not resist.

Multiplying bamboo

The division of bamboo is never done in spring; only in winter, from December to March.

Maintenance of bamboo

No need to add fertilizer. The grass brings nitrogen naturally, a mulching of lawn mowing (the first mowing of spring and the last one of summer) of 8 cm thickness is enough to feed them, while preventing the development of weeds.

Bamboo is a grass; if you feed it too much, it will grow but become fragile at the thatch level. It can break or even rot.

The life span of bamboo

It is programmed in their genes: for a given species, whether they are one year old or 100 years old, whatever the continent where they are, all die at the same time, having previously flowered and gone to seed to reproduce.