Roses: Summer care

Photo: Thinkstock

The growth can start to look straggly, many of the leaves look a little heat stressed – and where have all the flowers gone? Given the right treatment, though, roses can continue blooming right up until the edge of winter, so there’s plenty of colour still to come. You just need to know the tricks for bringing on a splendid display.

What to do in summer

Clean up
Remove any dead leaves from around the base of the plant, as these often hold spores of fungal diseases such as black spot and rust. Throw them in the bin, not the compost heap. Trim any dead or diseased leaves from the plant itself and remove spent blooms, cutting just above a leaf joint. Deadheading, as this procedure is known, helps to encourage more flowers to form.

Feed
Fertilise your plants with a rose food product, now, to encourage blooms and sustain the plants up until their leaves begin to drop in winter. In frosty zones, the general rule is that you should stop feeding about two months before the first expected frost, otherwise you may encourage a flush of late growth, which is vulnerable to frost damage.

Mulch
Top up mulch where it has broken down, to keep the roots well insulated. However, if the old mulch is covered with dropped (and possibly diseased) leaves, it’s a good idea to remove it all and re-lay fresh. In cold climate zones, a layer of mulch is useful to have through winter, too, as it helps to insulate the roots from ground-level frosts.

Spray
The most common disease of roses is black spot, which shows up as yellowing leaves dotted with black spots. It’s more prevalent in humid weather, so can be quite a pest during late summer and autumn, especially in coastal areas. Remove and destroy any affected leaves, and spray with a rose fungicide. Scale insects on the stems and branches should be sprayed with a horticultural oil, such as PestOil, and aphids clustered on new growth or flowers can be sprayed with any general-purpose garden insecticide (or squashed between gloved fingers, if you prefer!).

Roses and their colours

1. MAUVE is one of the more unusual rose shades. It represents enchantment and sends a message of love at first sight.

2. YELLOW is a symbol of friendship, affection and platonic love.

3. WHITE represents purity. White roses are associated with youth, young love and can also send a message of loyalty.

4. RED is the traditional symbol of romantic love and the colour of choice for Valentine’s Day.

5. ORANGE expresses fascination and attraction – with an underlying note of passion.

6. DARK PINK roses symbolise gratitude, so they’re great for saying thank you. Pale pink shades represent happiness and admiration.

More gardening tips:
Companion planting
How to grow perennials
Orchid: How to grow and care for
Problem spot planting
Designer plants
gardens

Looking after cut roses

If you’re giving a bunch of roses or are lucky enough to receive them, try these tips for keeping your blooms looking their best.

1. If cutting flowers from your garden, do it in the cool of the day and plunge the stems immediately into water.

2. Before arranging them, re-cut the stems under water, cutting at an angle.

3. Strip off any leaves that will end up sitting below the water level of the vase – otherwise they will rot and shorten the life of your flowers.

4. Rinse out the vase with bleach immediately before using it (a little bleach residue will not harm the flowers).

5. To give your roses the longest vase life possible, add a flower preserver to the water (available from florists and many nurseries). Or, dissolve a teaspoon of sugar and a drop of bleach in the water before adding the flowers.

6. Top up the vase water as the level drops, and change it after about four days.

How to cross-pollinate roses

Step 1 A partially open rose is chosen as the ‘pollen parent’, and all the petals are removed.

Step 2 A fully blooming rose is chosen as the ‘seed parent’ and, again, all the petals are removed.

Step 3 The flower stamens are trimmed off the seed-parent flower, to reveal the central part, known as the stigma.

Step 4 The pollen parent is cut off, held by its stem, and dabbed onto the seed parent. As a result, the pollen from the stamens attaches to the sticky stigma of the seed-parent plant.

Step 5 To protect the newly pollinated seed parent, a paper bag is placed over the flower.

Step 6 After a few months, the rose seed head (known as a ‘hip’) will have ripened and the seeds can be removed and planted out. All the resulting roses then have to be trialled to determine their flower colour as well as their constitution.