May is the month for Lilacs. There are some twenty species and many cultivars of Syringa and just about everywhere during this spell they can be seen putting on a marvellous show of clustered flowers with a fragrance that is quite unrivalled in the plant kingdom. The range of colours is exciting in a rather muted way, though there are a few bright or mysteriously, deep purples that make their present felt (S. ‘Mrs. Edward Harding’ and ‘S. ‘Charles Joly’ respectively, spring to mind) However, if you prefer the pastel shades then opt for varieties such as S. ‘Katherine Havemeyer’ or S. ‘President Lincoln’- the first has double flowers of pale purple and the latter is a lovely blue, both give off wonderful fragrance. For a striking white, the beautiful, double-flowered S. ‘Madame Lemoine’ is the obvious one to recommend. Syringa is an easy plant to grow so long as your soil is not on the acidic side. It prefers chalky and fairly fertile, free-draining soil and will in time get up to somewhere around 6m with a spread of about the same over time. One should prune lilacs in the summer and winter to avoid weak, straggly growth. As the flowers fade, cut back their shoots to a pair of leaves just below the flower head. In winter, prune weak branches back to their base, remove suckers and thin out the old wood. Lilacs can look a little uninteresting between flowering periods, but one way to extend their appeal is to make their structure work for you and have a late-flowering climber such as Tropaeolum speciosum or one of the less vigorous, autumn-flowering clematis varieties climb through it.
Ramblers, climbers, scramblers, whatever you choose to call them, collectively they make up a very beautiful plant group and can prove extremely useful in many ways. They can add height and structure to your garden, they can disguise unsightly structures and they can add seasonal interest with their flowers and foliage in areas where other plants have finished flowering or have yet to bloom. They are very diverse group also. Some attach themselves to supports with tiny suckering pads, others use modified leaves to twine around things and pull themselves upwards and there are yet others that use thorns or aerial roots to achieve this task.
Form and size vary enormously. The first thing to do when deciding which climbers to choose is to assess the size of the site they are to fill, remembering that while they may not take up very much space on the ground, they might very well engulf areas above often to the detriment of any surrounding plants if the choice of plant is unwise. For example, a small shed may look very pretty adorned with a passionflower (Passiflora careulea) or one of the smaller Clematis such as C. florida ‘Sieboldii’, but bedecked in the much more vigorous Clematis montana or say a Rosa ‘Rambling Rector’ then access might become virtually impossible, not to mention the injuries one might sustain from the thorns in the case of the rose. It is therefore always best to do a bit of research beforehand by measuring up the area you wish to cover and then matching this amount with the likely spread and height of the climbers you like best. And better to leave the thorny devils, beautiful as they may be, to more out of the way places.
The aspect of any given site will also determine which plant to buy. Some climbers such as ivy or the climbing hydrangea, Hydrangea petiolaris, cope well with a fair amount of shade, but plunge a Campsis or a Solanum into dense shade and you will probably condemn them to a slow death while they rather pathetically stretch their stems out in every direction in search of some much needed sunlight then, weary from the effort, eventually give up the ghost. One should pay attention to where the sun lands in your garden and if you are deciding which plants to buy during winter or early spring make your judgment while taking into account how much more shady sites beneath trees will be when they are in leaf and how much sunnier some sites will become when the sun is higher in the sky.
A little advance investigatory work into how a plant actually climbs will let you know whether or not some support is necessary. Self-climbers such as the Virginia Creeper, Parthenocissus quinqefolia and the afore-mentioned ivy and climbing hydrangea will need no help to climb for they are equipped to do this job themselves. However, many other plants that use tendrils or thorns to climb will need to be tied into a framework of wires stretched between vine-eyes, these should be driven into the mortar between bricks or firmly hammered into wooden structures before the plant is in the ground. One can choose to tie plants into the wire network in either a formal pattern, in a grid for example, which may be appropriate in a formal garden, or informally, if preferred. This should be done regularly during the growing season as the plant develops and demands new places to fasten itself on to.
While there are countless perennial climbers that will fill sites wonderfully year after year, be it a rose cloaking the boughs of a tree or a hard-working evergreen keeping an ugly wall hidden behind its dense foliage, let us not forget the merits of annual climbers which, in the same way as many of their earth-bound relatives can add colour and variation to a garden just as beautifully and very inexpensively. Many annuals can be grown from seed and be used to fill containers or gaps in the garden where they will, given something to sprawl over or cling on to, quickly grow, flower and fill their space in a much more natural looking way than many of the common bedding annuals that look entirely plonked and temporary in our gardens every summer. Among the best are the common nasturtiums, Tropaeolum majus, Morning Glory, Ipomoea tricolor, or, if you want something just a little more exotic looking, Cobaea scandens or Ipomoea lobata, both bear exciting and unusual flowers right through the summer and on to the first frosts if they are given a sheltered spot with plenty of sunshine.