The products made from bones - bone meal and bone flour, according to how fine the particles are ground - and intended for horticultural use, have to be quite clear of a dreadful disease called anthrax.

The first point to realize is that, in dry conditions, both peat tailings - usually taken to mean the more- coarse pieces that do not pass through a sieve when granulated peat is being prepared from the raw `as dug’ - and bark have a quite prodigious ability to absorb moisture. Even more than they soak it up from whatever surrounds them, they will attract and draw it up and sideways through the soil from some distance away.

You can imagine, therefore, that if this material is dry when put into the soil, it will very quickly soak up all the available moisture, and your plants will go short.

Secondly, both tailings and bark are in the early stages of decomposition (`short’), when the bacteria involved require plenty of oxygen and nitrogen for their own body processes. Dug into the soil, the bacteria quickly exhaust the soil atmosphere, and then turn their attention to the nitrogen in the plant nutrients in the soil solution.

The English walnut, one of the best known of nut trees, grows in Zones 5-9, but varieties differ in their adaptability to climates. Good choices east of the Rocky Mountains are Broadview, Colby, Hansen, Lake and Metcalfe, and the Carpathian variety from the mountains of Poland. For the northern part of the West Coast good varieties are Concord, Eureka, Franquette and Mayette; for southern parts of the West Coast recommended varieties are Carmelo, Drummond, Payne and Placentia. The trees become 40 to 60 feet tall with an equal spread and usually begin to bear 1 1/2- to 2-inch easy-to-shell nuts four to seven years after planting. Trees live 60 or more years; a mature tree bears 6 bushels of nuts annually.

Cut the top of walnut trees back about halfway at the time of planting. As the tree grows, prune off branches to leave a single trunk and gradually remove the lower limbs so that there is room to walk beneath the branches. Train the tree to have three to five main branches, well spaced, 8 to 12 inches apart, and forming angles greater than 45 degrees with the trunk. Little pruning is necessary thereafter except to remove deadwood and crowded or crossing branches. Pruning should be done in the summer or fall because trees bleed heavily if they are cut in the spring.

The tub size would suffice for a miniature bush type, but is a little small for a weeper. However, it is worth trying if you hear in mind that the small tub size emphasizes the risks of drying out and rapid exhaustion of nutrients due to the frequent watering required, inherent with all plant containers like tubs, troughs and window boxes.

Therefore, you will need to provide a growing medium with better ability to absorb and retain moisture than can be derived from ordinary garden soil. Crock the bottom with a little plaster rubble if you can get it, crushed brick or broken pot, and plant into a compost made up of three parts John Innes No. 2 potting compost, and one part moss peat which has been well moistened.

The peat has to absorb and give moisture, and you don’t want to start with dry peat absorbing moisture from the soil. Frequent watering can cause settling and packing, so you will have to guard against that. Mix in a third to one half part crushed plaster rubble - this is to be preferred for the gypsum content, but failing that, settle for coarse sand.

At the Parks Dept. nursery where I worked for some time, we produced a vast number of roses every year for the London parks, and it was one of the reasons for some disparaging regard among the gardeners there of the standard of gardening ‘outside in the parks’ compared with the standards set in the nursery that there was always complaint about mildew, whereas it was seldom if ever seen on the roses before they left the nursery.

It was simply put down to ‘rotten looking after as soon as they leave here’. Years after, when I had learned a great deal more than I knew then, I realized that there was most likely another explanation.

The manure is concentrated and, as with any other, it is quite capable of causing scorch. The best policy, therefore, is ‘little and often’. During the second half of March, sprinkle the dry powdery material either generally at about 1 ounce (28g) per square yard (square metre), or a level dessertspoonful - no more - around each rose at 8-12 inches (20- 30cm) distance from the stem, and scratch-hoc into the soil or mulch surface.

It is necessary to describe the aphid reproductive process so that you can ‘know thine enemy’, and understanding how the population explosion occurs explains why control measures have to be very thorough.

A 95 per cent kill achieves little because the remaining 5 per cent quickly replace their lost sisters - with interest. It requires little imagination to appreciate the cumulative effect of so many creatures each sucking the life out of a plant, stunting and weakening it, making the plant suffer, struggle and become less able to resist fungal attack. You may have regarded the little greenfly as not particularly serious, but I hope that this changes your mind, it is an insidious dangerous beast.

Furthermore, as strange as we may find the reproductive process, the feeding procedure is also rather unusual. It consists of inserting a very slender tube into the plant cells, sucking out the liquid sap, absorbing the nutrients it needs, and ’spewing’ or ’spitting’ what is left back down the tube into the plant again.

About 30 species make up this natural genus of mainly epiphytic plants, which originate from Brazil, Peru and as far north as Panama. Several species are in cultivation, the most popular being Bifrenaria harrisoniae, with its strikingly beautiful colouring.

The monopodial plants vary in size, and, of the 200 or so species, many can be found in cultivation. Among the smallest is Angraecum distichum, a dwarf plant with plaited (braided), herringbonelike foliage, whose oval leaves overlap along a curving rhizome, which rarely exceeds 15cm (Gin) in length. The minute flowers (5mm/Yin wide) are produced singly all over the plant, to resemble stars in a night sky. The giants of the genus include the magnificent A. sesquipedale.

All the plants are evergreen and epiphytic, some of the barbigerum smaller species being known as “twig epiphytes” because they cling to the very extremities of the smallest branches. Bulbophyllums are widely distributed throughout South-east Asia as well as Africa, Australia and tropical America. They must be regarded as one of the most successful genera among the orchids.

Before we come to the best time to use horse manure, two important points need to be made. First, the manure should be ‘well rotted’, and that means that it should have been composted, turned and aerated sufficiently to enable the decomposition processes to have progressed to a point where it is no longer possible to identify what it was to start with. By this time, it will have the consistency and colour of peat.

A clean cut makes healing tissue and repairs quickly, whereas a jagged wound doesn’t make healing tissue so readily, and the adventitious growth won’t form. The tall stems of standard roses and fruit trees will often throw off sucker shoots.

These should be removed while they are still infantile and brittle enough to be rubbed away by thumb or fingers. If you neglect them and thus allow stem shoots to become established, there is the risk that pulling away can break or seriously harm the stem.

Almost all bush roses are propagated by budding just above soil level, and standards by implanting the bud high up on a briar stem. As soon as the nurseryman can see that the bud has ‘taken’ he removes the original ‘wild’ stock foliage and growth above the bud so that sap and energy is diverted and concentrated into the choice bud.

Cattleyas were the earliest of the showy, tropical epiphytic orchids to be grown and flowered in cultivation. The first was Cattleya labiata, introduced from the mountainous forests of Brazil in 1818.

All the species are lovely and extremely showy, but many had been difficult to find in cultivation until recent breeding programs increased the availability of some of the finest types, such as the fabulous varieties of L. purpurata from Brazil.

These names can easily be unravelled to identify the specific genera as Sophronitis, Brassavola, Laelia and Cattleya, but when more than three genera are involved, the name given to the resulting cross is personalized to one individual, making the name less clear on the label. Potinara, for example, is the result of crossing Brassavola, Cattleya, Laelia and Sophronitis. With such a complex alliance, it becomes impossible to describe the typical “cattleya”, although all related hybrids are loosely referred to collectively as cattleyas, whatever their make-up.

While some authorities consider all cirrhopetalums as part of the huge, closely related genus Bulbophyllum, others keep them distinct. There are obvious similarities between the plants, which often cannot be distinguished out of bloom, but the flowers can be horticulturally recognized by the extremely long and tapering sepals produced by the majority of the species.

The plants were at one time included in the genus Oncidium, but are now considered distinct, although the latter name persists in orchid-growing circles. Very few of the species, and virtually no hybrids, are cultivated.

Culturally, cirrhopetalums require the same conditions and treatment as bulbophyllums. The species exhibit their twirling flowers in close umbels at the end of slender flower spikes. The overall effect of the closely aligned flowers, with stumpy petals touching and the elegantly tapering sepals forming a distinct waterfall, is quite captivating. The colours can be strong, with red being the main colour. The small, often glossy or wet-looking, projecting lip attracts flies on the lookout for raw meat.

For the beginner or collector, there are several kinds to look out for. ‘the complex hybrids produce plants with stout green foliage and a single, large, rounded bloom in a variety of colours, from yellow and green through to red, brown and bronze.

In between, are numerous, delightful plants of modest size with brightly coloured blooms which are predominantly yellow. Many of the species are in cultivation, and these are easy to grow and flower, finding favour among beginners for their reliability.

The pouch is designed to trap a pollinating insect by first enticing it to the edge, where it then loses its grip on the slippery surface and tumbles in. Once inside the pouch, a ladder of small hairs enables the insect to force its way out between either side of the pouch and the column. As it does so, the insect takes the pollen with it.

These Paphiopedilum Claire de Lune handsome blooms are usually spotted, often with dramatically dorsal petals. Their flowering extends into the sumer, overlap further group that produces multiflowering spikes. These are hybrids from species such as the extremely ‘kart petalled Paphiopedilum sanderianuo: rothschildianum, with its rigidly hek petals. These, and P. parishii, with its am twisting petals, have produced some lovely hybrids that add a dramatic dimension to the genus.