Conseils Jardin

On constate que certaines plantes ont souffert du froid ou n’ont pas résisté à des températures qui caractérisent notre région. Le bilan doit être fait et les bonnes résolutions prises pour choisir les plantes adaptées à notre sol et aux températures hivernales qui ne sont pas « méditerranéennes » !

Toutes les plantes rentrées cet hiver retrouvent leur place en extérieur, il est bon de faire un bon « surfaçage » avec du compost.

Pour les Agrumes, un apport d’azote sous forme organique comme le « guano » est très bénéfique à cette époque de l’année et je vous conseille de pulvériser un engrais foliaire riche en oligo-éléments pour compenser la difficulté de ces plantes à capter les éléments nutritifs souvent bloqués par l’eau calcaire.

Les Oliviers fleuriront bientôt, pour prévenir les attaques de mouches il faut poser des pièges à phéromones qui éviteront la reproduction, donc les pontes dans les fruits en formation. Suspendre ces pièges à mi-hauteur des arbres et côté est.

Au Potager, vous trouverez une offre très variée de plants de tomates avec des variétés anciennes et c’est une bonne chose. Je vous conseille de planter dans un trou profond (30 cm) au fond duquel vous déposerez une poignée d’orties fraîches et de compost. Enterrez la tige du plant de tomate sur 15 cm ce qui renforcera l’enracinement. Paillez le pied et n’arrosez pas en excès pour garder une bonne qualité gustative.

Les gazons demandent beaucoup de tontes mais ne coupez pas trop court ce qui limitera les besoins en eau. Pensez à laisser certaines zones « libres » dans lesquelles vous ne couperez jamais l’herbe, où se nichent de nombreux insectes, afin de laisser des espaces de nourriture aux oiseaux.

La taille est réservée aux arbustes à floraison de printemps, qui est maintenant terminée, comme les Forsythia ou les Lilas. Je vous conseille une taille qui consiste à supprimer certaines branches anciennes pour permettre la naissance de nouvelles pousses depuis la base des plantes.

Les Chrysopes sont des insectes qui se nourrissent de pucerons, araignées rouges, psylles et cochenilles floconneuses, donc des amies du jardinier. En cette période vous pouvez acheter des œufs à déposer sur les plantes qui ont la présence d’insectes indésirables.

Une adresse : www.lamaisondesinsectes.fr

Bon jardinage à tous …

Jean-Yves MEIGNEN
Jardinier de l'Abbaye de Valsaintes.
Consultant à domicile et concepteur de jardins.
www.valsaintes.org
www.roseraie-abbaye.com

Welcome back Ladybirds

As soon as the first rays of sunlight appear in Spring, the ladybird leaves its nest where it been hibernating during the winter. There is just one thought on its mind, to reproduce. The male flies around to find a female, when found, grips her tight and settles himself firmly on her back, and starts fertilising her eggs. This operation can take several hours.

If he leaves too soon, another will arrive to finish the job. As soon as the fertilisation of the eggs is completed, the female ladybird searches for the nearest colony of aphids and deposits 50 yellow eggs very near to them. This whole operation takes place several times during her productive period.

To realise the size of the eggs, the red point is the head of a matchstick.

After 5 days, the eggs become grey, a transformation, which announces the arrival of the larvae.

The larvae is blue-grey in colour, eats its way out of the egg, devours what is left over of the egg, and as it makes its way towards the aphids, it gulps down a few of its sisters. But its main interest lies in eating as many aphids and other sucking insects as it can, which it manages to do in record time. The larvae eats 100 aphids per day.

A ladybird larvae

As a comparison an adult ladybird only eats 5000 aphids during its lifetime (about 2 years). The larvae sheds its skin 4 times in 1 month. After the shedding is finished, it glues itself onto a twig (glue is produced by its abdomen), the pupal stage has arrived.

Pupal stage

After 8 days, the ladybird brakes out of the shell. Little by little the black spots appear on the new born ladybird, it takes several hours before the shell has turned red. The red is to frighten off its preditors especially birds. When disturbed or attacked the ladybird ejects a yellow liquid that has a disagreable smell and tastes bitter. This defense does not work with ants, spiders, bugs and other insects. Flies and certain type of wasps even lay their eggs directly into the ladybird's body, parasiting it.

The ladybird with 7 spots is the most common ladybird, but there are about 80 different type of ladybirds in France alone (3000 known species in the world). Ladybirds come in all sorts of colours, red, yellow, orange, pink or black with 2 to 22 spots.

Be aware of the Asiatic ladybird. It was imported in the beginning of the 20th century , then used on a massive scale in the 1980s as a biological control against aphids, it has become invasive and is eliminating certain native species.

An Asiatic ladybird comes in different shades and number of spots

In biological control against aphids, it is enough to use two to three European ladybird larvae to control an aphid invasion as they eat 100 aphids each per day. Before you deploy them you need to make sure there are aphids around (normally in April), if not, there is nothing for the larvae to eat. A smal paintbrush can be used to deposit the larvae on to the plants and fruit trees. Make sure that there are no ants about as they seem to protect the aphids from the larvae. The larvae can be obtained from specialised shops or from OPIE (Office Pour les Insectes et leur Environnement) tel : 01 30 44 13 43 www.insectes.org

Bibliograhy : Rustica, Bienvenue aux coccinelles by Colibri et Alain Raveneau

wild irises

Each year during April the plateau at the top of les Adrets (hills surrounding Correns in the Var), is covered with wild irises, Iris lutescens, Valeriana tuberosa en wild tulips, Tulipa sylvestris subsp. australis. It's a sight for sore eyes.

Photos made by Elisabeth Boutevin

Tulipa sylvestris subsp. australia

Valeriana tuberosa

Iris lutescens (much rarer than the yellow or purple)

Bonsai and Acers

Last Tuesday (20 April) we had our first garden visit of the year to Marina & Phil Hacker, who live 7 km outside Vidauban on the way to La Garde Freinet. Phil's special interests are Acer palmatum (Japanese maples), Bonsai and Koi fish.

In their Japanese garden local red/brown boulders have been used, interspersed with Japanese maples.

The following are some of the plants used in the Japanese garden:

Acer palmatum Katsura, green leaves, tipped with red

Acer palmatum Nomura, larger growing maple with deep purple leaves that turned fiery red in autumn,

Acer palmatum Osakazuki, has larger leaves, with 7 lobes, that turn brilliant scarlet in autumn;

Acer palmatum var. dissectum, has 7- to 11-lobed leaves, each deeply and finely cut, turning gold in autumn,

Acer palmatum var. dissectum atropurpureum, red variety, with deeply and finely cut leaves;

Cotoneaster "Coral Beauty"

Chaenomeles speciosa (Japanese Quince) in several colours (white pink and red).

If you are thinking of growing Japanese maples you need to make sure your soil is acidic. The only maple that tolerates alkaline soil is Acer griseum (Paper Bark Maple), which is not a Japanese maple.

The garden has 3 ponds, the larger one with enormous Koi's, a smaller one for the new born Koi and one for the "Oranda"goldfish.

Phil's special interest are Bonsai's. A special built greenhouse, houses Phil's collection.

The word Bonsai comes from the Chinese word 'Penjing". It literally means "Tray Cultivation" Bonsai history goes back to the 6th century when imperial personnel and buddhist students from Japan returned from China bringing with them plants in containers. The following is an extract from the first Japanese fiction work "Utsubo monogatari" (The Tale of the Hollow Tree): Quote "A tree that is left growing in its natural state is a crude thing. It is only when it is kept close to human beings who fashion it with loving care that its shape and style acquire the ability to move one" Unquote. This illustrates very clearly the thoughts behind Bonsai.

Normal grown trees are used to produce Bonsai trees. By pruning, root reduction, potting, defoliation and grafting a small tree is created that mimics the shape and style of mature, full-sized trees.

Phil explained the first step in creating a bonsai. He starts off with selecting a nice growing branch from one of his mother plants growing outside his greenhouse. Japanese maples are fairly easy to propagate. He removes a small circular strip of bark, rubs rooting powder on the cut, wraps it with sphagnum moss, and packs it in a small plastic flower pot that has been cut in half to fit snugly around the branch and fills the flower pot with special Japanese clay soil called "Akadama". After two months, roots will be growing from the cut and the branch can be severed from the mother plant. The best time to propagate is from mid to late May.

His greenhouse is filled with Bonsai trees, one in particular, is an olive tree that was killed by a severe frost in 1857, it regrew, was then killed again in 1956 by frost, the regrowth since 1956 and the way the bark was formed made it an ideal speciman for Bonsai.

Some of the techniques used:

Leaf trimming; selective removal of leaves or needles.

Pruning; the small size of the tree and the dwarfing of the foliage is created by pruning the trunk, branches and roots.

Wiring; wrapping copper or aluminium wire around branches and trunks is done to create the desired shape.

Clamping; is used for larger specimens or stiffer wood to shape trunks and branches.

Grafting; some species do not thrive on their natural root stock, their trunks are often grafted onto harder root stock or the method is used to add branches and sometimes roots.

Defoliation; dwarfing of foliage can be accomplished in certain decidious Bonsai by partial or total defoliation of the plant partway through the growing season.

Deadwood; bark from an entire branch is removed to create an impression of deadwood or strips of bark can be removed from areas of the trunk to simulate natural scarring.

Needless to say a great number of specialised tools are used to create the above effects.

To pot up the Bonsai, Akadama (clay), Kirui (sort of sand), both from Japan and Pumace from Italy are used.

Bibliography: Wikipedia the free encyclopedia "Bonsai", RHS A-Z Encyclopedia of Garden Plants, Explanations; Phil Hacker, Photographes; Elisabeth Boutevin

The Naming of Garden Plants

Common Names

Many gardeners ask "Why can't we just use common names?". The main hurdle is that plants are introduced from all over the world and therefore do not have common names in the language of the recipient country. It is of course possible to invent common names in the language of the country. In fact, this is already done extensively in the United States, but with no system to regulate or standardise names, confusion can easily arise.

A classic example in the English speaking world is Bluebell, referring to Hyacinthoides non-scripta in England, Campanula rotundifolia in Scotland, Sollya heterophylla in Australia and species of Mertensia in North America. The scope for confusion is enormous.

Botanical Names

Most people do not think twice about using Rhododendron, Chrysanthemum or Fuchsia, common names for three large groups of plants. The fact that they have passed into common usage demonstrates the great strength of botanical names - they are intended to be universal. The aim of the botanical naming system is to provide each different plant with a single name which can be recognised by anyone, whatever their own language.

What do the parts of a scientific name mean

Take as an example Digitalis purpurea. The first word is that of the 'genus', which includes all foxgloves. (Plants which share a number of significant features are grouped together to form a 'genus', in plural 'genera') The second word is the 'species' (species can be defined as a group of interbreeding individuals producing more-or-less similar offspring and differing from other similar groups by a number of key characters). These two words together (Digitalis (1) and purpurea (2) refer uniquely to the purple-flowering foxglove in W. Europe.

Digitalis grandiflora is a yellow-flowering species from C. and S. Europe. Sometimes a species is subdivided into subspecies (subsp.), varieties (var.) or formas (f); for example the white flowering variants of the purple foxglove is called; D. purpurea f. albiflora.

What is a cultivar?

In cultivation, variation within species and that generated by hybridisation is particularly valued. Plants exhibiting desirable characteristics of flower colour, habit, size, variegation, fruit colour, flavour etc. are often given names. These are termed cultivars (from cultivated variety). For example, a foxglove with variegated leaves has been given the name Digitalis purpurea 'Chedglow'. If there can be no confusion, the genus and the cultivar names may be used without the species name. Solanum tuberosum 'King Edward', Solanum 'King Edward' and even potato 'King Edward' are equally correct. However, 'King Edward' alone could be confused with the unrelated Achillea x lewisii 'King Edward.

What is a hybrid?

A cross made between plants of two different species results in a plant called a hybrid. This hybrid may be given its own scientific name. Thus Digitalis x mertonensis is the hybrid name for all plants derived from the cross between D. purpurea and D. grandiflora. The 'x' indicates the hybrid status. Many different cultivars may result from the same cross.

Bibliography: The Royal Horticultural Society Botany Advisory Services, January 2006