Online Tips from Gardening Experts

Topiary, the art of clearing shapes from evergreens, traditionally uses small-leaved plants such as yew, box, and privet that respond well to trimming. Individual specimens can be grown successfully in pots, but on a larger scale in the garden they need an open sunny site, sheltered from strong winds to encourage even growth, with access space for maintenance and viewing. Topiary should be trimmed regularly and slow-release fertilizer and mulch should be applied in spring to encourage healthy growth. While the shape is forming, check the ties regularly to ensure they are not cutting into the stems. Vertical growth is the quickest, followed by side shoots; downward-pointing stems, which should tie into the framework regularly throughout the season, growing slowest. Some stems are known as “frames,” and stay in place throughout the life of the topiary, while others are “formers,” which can be removed once the shape is established.

Topiary Garden

Shapes can be bought or you can make your own from chicken or fencing wire and canes ¡.e., the only limit is your imagination! There are magnificent examples of formal topiary at Levens Hall in Cumbria, UK, and at Tulcan Cemetery in northern Ecuador, which includes elephants and astronauts. Planes, trains, and even sofas grace many of Britain’s smaller gardens, often developed from existing hedges. While curves can be cut freehand, geometric shapes are more difficult and you will need spirit levels, plumb lines, and a straight edge, as well as a lot of patience and time, to keep them tidy.

Growth rate determines how often you have to clip the plant¡ªyew only needs one cut each growing season, while faster-growing Lonicera nitida (6-9) may need three cuts. If topiary needs repairing, cut back the damaged stems and tie in new replacement shoots. Start trimming in early summer; if in doubt, don’t trim. Pause regularly to review your progress.

Cloud pruning

Cloud pruning takes two forms: traditional Japanese priming of trees to create hare stems with dense “clouds” at the tips, which highlights the shape of the plant, and hedges trimmed into dynamic billowing forms. There are some wonderful examples of cloud pruning in country bouses throughout Britain. If you’re looking for inspiration, visit Walmer Castle in Kent. Box, yew, thuja, and cupressus can all be primed in this freeform style to create rounded shapes.

Bud Grafting

This technique is normally referred to as building. It is a popular and reliable method for grafting bush roses. Budding takes place in summer, usually on roses that are growing in the ground or in containers. The difference between budding and grafting is in the material used. Whereas both whip-and-tongue and saddle grafting use two stems of the desired variety, with bud grafting a single growth bud is grafted onto a rootstock. An ordinary sharp knife can be used for making the cuts, but a budding knife is best. This has a flattened end to the handle for opening the rootstock.

1. Select a well-ripened stem of the current year’s growth, making sure that there are dormant buds at the leaf axils. Remove the stem and take off all the leaves. Prepare the bud before opening the rootstock. Cut a single bud from the selected stem with the minimum of wood. Remove the sliver of wood from under the bark using the point of the knife and discard. This leaves the bud and the cambium layer attached to the bark. Keep the bud moist while you prepare the rootstock i.e., the simplest method is to hold it between your lips. It will be difficult to talk and don’t chew on it!

2. Now prepare the rootstock to receive the bud. Make a horizontal cut 1-2 inches above ground level and discard the top growth. Clean the stem of the rootstock with a rag.

3. Once the neck of the rootstock is clear you are ready to bud.

Explanation of Bud Grafting

4. Make a T-shaped cut deep enough to expose the cambium layer below the bark. The stroke of the T should be less than 1/2 inch long; the upward cut 1 inch long.

5. Use the flattened end of the knife handle to open the two flaps of bark on the rootstock. Slip the prepared bud, pointing upward, under the flaps of bark, making sure that the two cambium layers are together. Trim any surplus bud bark level with the stroke of the T.

6. Secure the union with raffia above and below, avoiding the bud. Some gardeners prefer to use budding strips made of thin rubber. These may be stretched over the bud union and held with an open staple.

Once the bud starts to grow, you can remove the raffia (If you use a rubber strip, it will perish). In early spring, cut the rootstock above the new bud growth leaving it to flourish and flower that summer.

Most gardeners manage to grow almost anything they want with the aid of a cold greenhouse, a heated propagator inside it, and a sheltered garden outside. Nevertheless, they will still need to make a choice as it’s not possible to grow everything under cover where space is often very limited! When choosing what to grow, be imaginative, you could go for foliage plants to give you year-round interest and color, depending on your degree of heat. The weather being kept off allows for some spectacular shows and these will endure much longer than most flowers. In a conservatory, it is probably more important to choose well-formed or well-shaped plants with good foliage. Indoor topiary, trained climbers, and tender wall shrubs all offer great potential and aesthetic interest without cropping or even blooming. Many flowering plants have great perfumes, which are more intense when grown undercover and many, such as the daturas (Brugmansia spp.), gardenias, citrus, and hoya are all good conservatory subjects and would also do well in a warm greenhouse. Cool and cold greenhouses can have excellent shows of “normally” outdoor flowers, and over a much longer season. They are especially good for growing cut flowers to bring into the house. Food crops are usually absent in a true conservatory, but don’t forget that certain herbs and cirrus will do well there in winter. At the other end of the scale are poly tunnels. People always imagine poly tunnels are useful only for utilitarian crop producers, but they can be extravagantly planted with gorgeous flowers for your own, very private show! I use mine for pineapples, bananas, and guavas, and new potatoes in time for Faster. However, it’s your space-so grow what you want.

Forcing plants

One of the problems in winter is that there is insufficient light for plants to actually do much real growing. Plants that store up energy underground can be coaxed into growth by providing warmth, often from underneath. Plants of asparagus, seakale, rhubarb, and Belgian endive all benefit from being brought into the warm (and usually dark) indoors, where they are forced to throw succulent new shoots for our culinary delight.