Mary Keenan’s Garden Diary: ways with roses

Roses are found in almost every garden in the country, including ours, and it is little wonder – what other plant offers such luxuriant and often richly scented flowers over much of the summer, in such a wide range of colours and growing habits that there is one suitable for almost every spot in the garden?

They’ll clothe walls, fences and arches, fill borders or pots with their opulent blooms, make lovely cut-flower displays for indoors and several rose species add autumn interest with their sculptural hips that feed wildlife.

The way you grow your roses is limited only by your imagination. To create a decorative and permeable divider in our garden, we constructed this rose swag feature.

It incorporates a picket fence that visually and physically separates the ornamental garden from our nursery growing area and is a good alternative to a hedge as it occupies much less space and allows space for a border of perennials and other flowering plants beneath.

Solid, wood posts, 150mm square and 2.4m high are firmly secured in the ground at 3.5m spacing. These are drilled through, near the top of each post and threaded with a chunky, 40mm-diameter, synthetic rope that dips slightly in the middle. The drop in the rope can be positioned at eye level to provide a visual distraction and screening of undesirable views.

At the base of each pillar is planted Rosa ‘American Pillar’, a vigorous rambling rose that blooms exuberantly from late June into July bearing dense clusters of single, carmine pink flowers with a white eye. We have opted for just one variety for impact rather than having lots of different types which can look disjointed.

Each rose is trained by bending the main shoots gently around the posts in a spiral and then winding them around the ropes. The idea is to train the stems as horizontally as possible, which encourages the formation of lots of side-shoots and more prolific flowering. Other plants such as clematis or honeysuckle could be included alongside the roses in this planting to prolong the flowering season.

Summer care of roses

If you’re new to gardening, don’t be put off by a perception that roses are complicated. All fare best in an open, sunny site where they’ll benefit from good air circulation and the foliage can dry off rapidly in the early morning to prevent many types of diseases.

Roses are hungry plants, so mulch annually with organic matter, such as well-rotted animal manure, and consider using a rose feed to promote flowering in summer. Being high in potassium and phosphorous, Uncle Tom’s Rose Tonic is a go-to product for many rose growers. It promotes strong, healthy growth rather than lush, lanky shoots prone to disease. The foliar feed can be sprayed on every 14 days or so during the growing season.

Mulching also helps slow moisture loss from the soil and keeps roots cool, which can reduce potential problems with mildew on leaves and flower buds. Roses, and other plants such as asters and phlox, are more susceptible to mildew when they regularly dry out around their root area.

Keep the summer flowering displays looking good by regularly removing faded blooms but don’t deadhead rose varieties that produce attractive autumn hips or you will get no hips.

Although modern roses are generally much more disease-resistant, they can still suffer from common diseases like blackspot which defoliates and weakens the rose, and pests such as sap-sucking aphids.

Companion planting is an effective organic way to reduce aphids and other common diseases in roses and other plants. I have found alliums or ornamental onions especially useful companions when planted together with roses.

Their strong scent wards off aphids and other pests and they help roses combat black spot, mildew and other fungal diseases by exuding biochemicals with allelopathic properties that inhibit diseases.

While these widely held observations have yet to be supported by sound scientific research, from my own experience, there would appear to be clear benefits to the association of roses with alliums.

Plant allium bulbs among your roses in mid to late autumn, at the same time as spring-flowering daffodils and tulips.

Cut back the long, straggly, ‘whippy’ shoots on your wisteria once the flowers have gone over. They should to be cut back to leave just five or six buds or leaves on each shoot, so count upwards from the point where they started growing this year and snip them off neatly above a bud.

This pruning controls over-vigorous growth and encourages the plant to focus its energy on flower buds for next year. Wisteria flowers on old wood, meaning that the flower buds that will bloom next year form on this year’s growth. The plant will continue to grow this summer and will need pruning again in winter to control its size and shape.

Mary Keenan and Ross Doyle run Gash Gardens, Co Laois open to the public. www.gashgardens.ie