Spiraeas have filled so many ugly gaps for me that it would be easy to take them for granted were they not such attractive shrubs. Most species have a graceful arching branching system, dainty foliage, and white flowers, except in the species Spiraea x bumalda.

The graceful weeping branches are lovely when sufficient space can be given for full unrestricted development. Vitellina is very like the above but the young shoots are yellow and the annual growth less vigorous.

Of this genus none can rival our native Rowan or Mountain Ash. Even when grown in some suburban gardens the deeply divided leaves and orange-scarlet berries hint of the wide reaches of moor and lonely upland loch. First, in alphabetical order must come the whitebeam, Sorhus aria, with leaves which are green on the upper surface and silver grey underneath. The fruits in autumn are highly coloured and irresistible so far as the birds are concerned.

Salix hastata wehrhahnii, of similar stature, makes a picture when each naked branch is studded with large pearl-coloured catkins in April. Any moist soil will support a willow even if the water content is maintained by a thick mulch of peat. Cuttings of any young shoots removed at leisure and pushed into moist earth will root with nearly one hundred per cent. success.

Hydrangeas are not remarkable as foliage plants as a rule, but so outrageously floriferous they command immediate attention the instant buds show colour. Hydrangea arborescens grandiflora at 5 ft. vies with H. cinerea sterilis in the grossness of the white balls of bloom.

Both are lovely grown against a dark background of evergreens. The blue and white flowers of H. involucrata on 18-in. stems provide just the right softening influence to the lustre of the orange lily Enchantment, so I mix them up like a floral salad in a bed dominated by a sombre yew.

Some plants radiate a positive bonhomie, and in this respect St John’s Wort has few equals. In the old herbals it is credited with the ability to cure melancholy, so the prudent gardener should always have a bush on hand, at least on budget days!

Just as good-natured people are usually called upon for all the arduous chores, so do we tend to take advantage of plants like hypericum which will grow in the least salubrious corner of the garden.

We all have our problems when it comes to plant care indoors, hut in future when your rubber plant decides to shed a leaf.

Adjustable shelves make it possible for a wide range of smaller plants to be grown very successfully. Under such carefully controlled conditions the saintpaulia does particularly well, and could well provide a specialist interest for the real enthusiast.

Some of the majestic screw pines have beautiful saw-edged yellow leaves and may attain a height of 8 to 12 ft. when roots are confined to a plant pot, or large tub. Tightly overlapping leaves radiate in all directions and may give the really super plant a diameter in the region of 12 ft. Tight, warm conditions are needed and, because of the saw-edged leaves, a position away from the general stream of humanity that may be passing. Alas, plants are in acutely short supply and take many, many years to .reach maturity, so it may be a little unfair.

Unfortunately there are all too few of these specimen plants available today. And to see them in their full glory they must be of specimen size when purchased, as many do not produce fully mat tire leaves until they are several years old.

Rosa alba Celestial makes a tall bush of 6 to 8 ft., grey leaved and superlatively lovely in a glory of pale pink sweetly scented flowers. R. banksiae lutea needs a sheltered, sun-warmed wall to show its true quality. The straw-yellow flowers are individually small yet carried in noble profusion ; the soft yellow flowers are followed by dark red hips.

Fruhlingsmorgen and Fruhlingsgold grow to a similar height, 6 to 8 ft., and are alike in leaf and smell, but the one has cherry-red flowers centred yellow, and the other petals of palest primrose.

I grow all the forms of R. moyesii available and when named varieties are exhausted I experiment by growing more from seed. R. moyesii Geranium is more compact than most with the typical delicate leaves, orange-scarlet flowers, and flask-shaped hips, while Sealing Wax has red flowers followed by orange hips backed by the soft yellow dying leaves. Nevada with white blooms and the bud sport Marguerite Hilling with pink- should also be included here for both have R. moyesii as parent. R. xanthina Canary Bird has the beauty of finely divided leaves with small canary yellow flowers in June, followed by vivid red hips.

What the visitor to public authority greenhouses fails to understand is that houses open to the public are really display greenhouses. In order to support the display there are usually many greenhouses behind the scenes in which plants are grown in individual environments from where they are chosen to fill spaces in the display greenhouse as and when required. The display greenhouse will have many permanent plants, but the majority will be fly-by-nights that may be in position for only a few days before being replaced.

It really is not practicable to grow a range of plants with differing temperature, humidity and light requirements together under the same roof and expect them all to do well. Frequently I am invited to inspect the plant collections of acquaintances and give my opinion as to why a certain plant does not do so well. More often than not the garden room enthusiast is paying the price of trying to emulate the example of the botanic garden display and meeting with the customary failure.

The owners of small gardens need to utilise every scrap of space and they, therefore, must be more selective in their choice of plants. Climbers and wall plants will provide the answer to many problems for they will add both space and height to congested sites and will bring colour to every available wall. However, enthusiasm should be tempered with discreet understanding for there are climbers which love to be baked into brilliance of flower by hot sun, whereas others must be soothed by moist shade.

I always use a soft string which will not chafe even the most tender bark and, which is perhaps more important, it will rot after a year or two. When indestructible material is used I grow careless about the annual inspection to ensure the stem is not being constricted by the tie. All wall plants must be looked over at least twice a year to make certain the stems are not being chafed or strangled by the supporting media.

I could till a book with a selection of climbing and wall plants but as before will restrict the choice to those which have been proven in the crucible of the garden. There are two species especially suitable for wall culture, butoboth need different treatment.

When drawing up contracts for office landscaping schemes of this kind the office chief should come to a clear understanding concerning plants that are likely to fail, so that they can be replaced without difficulty. No matter how wonderful the environment, maintenance and general conditions may be, it is almost inevitable that some plants will succumb.

Plants were required for raised beds in the pedestrian way of the L-shaped building. Temperature was to be maintained at not less than i6C. (60F.) and the principal source of light was to he from large, reinforced glass side windows. Plants were to be free planted in J.I.P.3 compost with good drainage provided.

One of the many advantages of these schemes is the flexibility they permit – it is no longer necessary to demolish walls to increase or reduce the size of particular departments; the screens and potted plants can simply he moved one way or the other in order to make the alterations.

The importance of landscaping office interiors with plants has gone sonic way beyond sending the junior to the nearest flower shop to purchase a rubber plant. Today there are specialists in the field who make the installation and maintenance of foliage plants in offices a full-time occupation.

With flowering plants it is always better to remove flowers as they die in order to stop them rotting and avoid fungus troubles. With saintpaulias and cyclamen it is particularly important to ensure that when flowers are no longer attractive the complete flower stalk should be removed.

Any pieces of the stem that may be left will rot back in time and damage the remainder of the plants. The majority of glossy-leaved plants will he improved for having their leaves cleaned periodically. Most of them can be simply treated by gently wiping the leaves with a soft sponge moistened in water.

You will have the satisfaction of knowing that the most competent expert in the land could not pot the plant any better, as it will be at exactly the right depth and the old and new compost will be in contact all the way round the pot. Better than that you just could not have!

If the garden room is attached to the house, then the house wall should be brought into use as a support for climbing plants. All sorts of fittings are available but I am still a great believer in the old-fashioned trellis as a means of support. The timber will be greatly improved by a couple of coats of white paint, which will set of the plants well. As an alternative to the conventional diamond-shaped trellis try making your own up in a squared rather than a diamond pattern.

You invariably feel indebted to the donor and, worse still, once you have accepted the bug-ridden chlorophytum, or whatever, you are obliged to keep it for fear of causing offence when the previous owner pays you a visit and finds his ‘gift’ missing from the collection.

Growing advice amounts to little more than keeping the plants in reasonably good light not full sun under glass watering and feeding regularly and potting on into reasonably large containers fairly early in the season. Try putting five or six cuttings in a large basket early in the season, mid-April say, and you will be quite amazed by the display provided with very little eflbrt on your part only a few months later.

Alders are often planted near water or in moist areas, but their ornamental attributes are often overlooked. Even the native forms, have interest. The cut- or golden-stemmed forms acid variety and interest, making them worth planting provided they are in the right type of soil. The soil is acid or alkaline. but prefers moist soil; dislikes very dry conditions

The species of real quality, Weigela florida, like so many other worthy plants, comes from China. The flowers are rose pink outside and like pale apple blossom within and they resemble a well-proportioned digitalis. I do not approve of the variety variegata, as I feel it reduces the dignity of the species, but I am very much in the minority in this respect. At 4 ft. it is 18 in. shorter than the type with pale pink flowers and leaves margined cream.