- Everything for New Zealand Gardeners
Design Plants How-To GardenHub
Kowhai - 'Sophora microphylla' Click Here for Article
   Plant Guide | NZ Natives | Roses | Rhododendrons | Plant Care | Plant Societies
Home Garden Tasks Garden Events Gardens Open Newsletter Subscription a-z Index Classifieds Garden Societies Site Map About Us Search

Member NGIA

Rose Care - Summer

Summer and the scent of roses. Whether you are a fan of heritage roses or their modern cousins, summer is your time.

Good care will give you healthy roses and more enjoyment of your roses, still our favourite flower.

Where and how you plant your roses will have a direct impact on how well they do. A rose needs sun to do well- choose a site that gets at least five hours of sun each day. 'Movement of air' the old fashioned expression for the space that allows good air circulation around rose bushes is essential to reduce the chance of fungal disease.

Regular watering is the most important chores in the summer rose garden. Dry and stressed plants are far more vulnerable to disease, and they won't flower at all well.

Try to avoid wetting the foliage; many modern roses are susceptible to disease when their leaves are wet. Watering in the evening means that plant and the soil are wet for a longer period, providing an opportunity for fungal disease.

A leaky hose delivers the water to the roots where it is needed and avoids water spotting the blooms.

Mulching is invaluable for conserving water, and a mulch applied to the garden in late winter will reduce water evaporation.

Wet Weather
If your roses have turned to mushy lumps, blame the rain. The outer layer of petals becomes soaked by heavy or steady rain, and then these dry hard, preventing the flower from opening. Find time to remove all these to reduce the opportunity for disease to take hold.

If lots of rain is your norm, think about planting single and semi-double roses, and not the very full doubles that have so much trouble in the wet.

A summer a mulch with compost, keeping clear of the stem or 'collar' of the plant, or feeding with fertiliser is needed, if using chemical fertiliser then follow the directions carefully.

Apart from fish fertiliser that can leave your roses smelling less than sweet for a few days, most foliar feeds are less effective than feeding the roots.

Deadheading will encourage repeat flowering, dead head regularly each week. It is a relaxing summer evening task and gives you can chance to check on the health of your roses. Remember that roses with plenty of foliage have proved to be more healthy and disease resistant, leave maximum foliage when deadheading, especially on floribunda and other cluster-flowered roses.

Weed your roses frequently and compost them. Weeds and roses compete for moisture, food and light. A weedy border will have poor air-circulation, increasing the chances that disease will take hold.

Fungal disease
There are three main fungal diseases that affect roses - mildew, black spot and rust. The spores of fungal disease carry over from season to season on the soil, and the removal of fallen leaves is important in reducing the incidence of fungal disease.

Healthy roses and some specific rose varieties are less susceptible to fungal diseases, so feed your roses.

Water, regular watering, is one of the most important things you can do for you roses as when they are dry and stressed they are far more vulnerable to disease.

Good garden hygiene such as removing litter, prunings and fallen foliage will help to prevent a build up of sites that encourage fungal disease.

If you have rose that is affected by fungal disease year after year, it is worth considering taking it out. Regular spraying can help to reduce fungal diseases. Organic gardeners need to seek more resistant varieties and avoid the highly bred roses such as hybrid teas and some modern roses.
  • Mildew is a powdery white substance that forms on leaves. Good air circulation helps to avoid this, but in warm, wet climates sometimes nothing seems to help.
  • Black Spot is dark spotting or 'splodges' on rose leaves and removing the affected leaves (including any on the ground) and burning them is essential.
  • Rust shows as rusty spots on the leaves, most obvious on the undersides of the leaves. Remove any leaves, including fallen leaves, and burn them.
Continued Pests

R. 'Nobilo's Chardonnay'

Nobilo's Chardonnay

Flower Carpet Coral

Flower Carpet Coral

Books on Roses
Books on RosesFor great books on roses see our Book Reviews
New Zealander Sally Allison's Shrub Roses and Climbers and Ramblers
World renowned expert Peter Beales' Classic Roses

Summer is for roses - R. 'Prosperity'

Summer is for roses - R. 'Prosperity'

More Rose Care and Garden How To

Roses Profiles your favourites, new roses and enduring heritage roses.

To spray or not to spray is a big question when it comes to pests on your roses. When you spray you also eliminate the predators; ladybirds and the like. These predators take longer to restore their population than the fast breeding pests do, so the problem seems to worsen when we spray and becomes and endless cycle. Toughing it out can mean some ruined blooms or bushes thick with greenfly, but natural predators will take over if you let them.

Growing a wide range of flowers to encourage predators will help enormously. Companion planting advocates growing members of the allium family, from chives to the supremely ornamental alliums, to encourage hoverflies and other beneficial insects. A border of chives has long been a staple in many rose gardens.
  • Aphids (greenfly) are common in any garden that has roses. Squashing them is one of the best ways of reducing the population. Sponging badly affected leaves with a mild soap and water solution also works. You can spray if you prefer. Take care to follow the directions.
  • Thrips can prevent flowers from opening, and flowers that do open can have black or brown marking. Thrips are tiny and very difficult to see, there are commercial sprays available if you wish to use them.
  • Earwigs can munch great holes in flowers overnight. They are found scurrying away if you pick your blooms.

    Earwigs emerge at night and spend daylight under stones and in crevices. Removal by hand at night or eliminating hiding places are good remedies. To be effective spraying has to be spray at night when earwigs are active.

    Create your own earwig trapAn earwig trap creates an ideal hiding place for earwigs, one you can tip out into the rubbish or the bird table the next morning.

Email this story to a friend

Aphid and Black fly
Aphid and Black fly


* Back to Top * Home * Roses * Plants * NZ Natives * Garden Hub * How-To * Garden Design *
Copyright 2001, 2002 Limited. All rights reserved.
Last revised 12 Jun '01