Rose care for temperate climate gardens: pruning, feeding & pests
Roses are not always the easiest plants to grow, but they are among the most rewarding of all with their colourful and often fragrant blooms for much of the year. There are a few tricks to follow to get them growing well in temperate climates like Sydney and the Hunter region. Here’s our rose guide that takes the angst out of rose growing.
Position
Roses need to grow in full sun with protection from strong winds. Over time, sunny positions can become shaded by other plants, so keep an eye on how much sunlight your roses are receiving. If necessary, prune back overhanging growth or consider relocating your roses to a sunnier spot in the garden. The ideal time to transplant roses is in winter, when they are dormant.
Planting
Traditionally, roses are sold when they are dormant in winter, but are also available as potted plants year round. Roses will flower in their first year of planting. The best planting time for dormant roses is winter, but potted roses can be planted year-round (however, you should avoid planting in very hot weather).
Bare-stemmed bushes are known as ‘bare-rooted’ or ‘bare-root’ plants. Their roots are bare of soil, but protected with sawdust or sphagnum moss and wrapped in plastic. This packaging is removed before planting into enriched soil. Dig in aged cow manure (such as Supersoil Cow Manure Blend) or well-rotted garden compost. Before planting, soak the bare-rooted rose in a bucket of seaweed solution such as Amgrow Seaweed Concentrate - you can later use the water to water in the plant. Dig a planting hole that’s as deep as the rose’s root system but wider. Make a mound in the base of the hole to support the plant, spreading the roots over the soil mound. Backfill with enriched soil, water in well firming into the soil, and surround the new planting with organic mulch such as sugar cane or lucerne.
For roses that come in pots, the process to plant in-ground is slightly different. Dig a hole in your enriched soil and place some fertiliser in the bottom, then water the hole well before the rose goes in. When placing your potted rose in the planting hole, don't tease the roots - leave them intact for best results. Backfill the hole with the surrounding soil, firming in well, then mulch as you would for a bare-rooted rose.
Small bush roses such as Floribunda varieties can be grown successfully in pots, but you'll need to use a good quality potting mix such as Supersoil Professional Rose & Citrus Potting & Planting Mix, a large pot and ensure the pot has good drainage holes in its base.
Standard roses should be supported with a strong stake. Weeping standards need a wheel-shaped support to take the weight of the weeping growth. Climbing roses require an arbor, pillar or trellising to support their growth and display their flowers.
Feeding
Roses need lots of regular nourishment through their growing and flowering season to keep them in flower and to encourage strong, healthy growth. Feed through spring to early autumn with a rose food such as Sudden Impact for Roses, which is available in granular and liquid forms. Apply slow-release granular fertiliser at least twice a year in spring and mid summer, along with a top dressing of manure mixed into the mulch. Sprinkle fertiliser around the base of the plant, ensuring it stays in contact with soil. Watering will gently wash nutrients into the soil. Liquid feed potted plants every few weeks and also liquid feed in-ground plants that need a boost. Roses don’t need feeding when they are dormant. As with all plants, it's important that you follow the directions on your fertiliser packaging to the letter - click here to learn why.
Watering
Roses are able to survive drought, but perform best with regular, deep watering at least once or twice a week (and more frequently in hot periods). Potted roses need daily watering in hot weather. Always direct water to the root system and avoid wetting foliage, which can encourage fungal disease. Cut back on watering through winter as plants enter dormancy. Watch for the return of growth in spring, which often coincides with a blast of early hot weather. Be ready with the hose, watering can or to turn on the garden irrigation system when the new growth and hot weather arrives to keep roses in good condition. Click here for a deeper dive into the best way to water your plants.
Maintenance and pruning
Roses have a reputation for being high maintenance plants, but most grow and flower well with targeted care during the year. For a comprehensive guide to pruning plants, click here.
In spring, dead head spent flowers, cutting back to just above a node (side shoot) as if picking flower. Remove any yellowed or diseased leaves (put these in a bag and into the rubbish bin).
In mid summer (around mid January to early February), lightly prune roses to encourage a new flush of growth. Cut back all flowered stems to above a node. Follow up this light summer prune with rose fertiliser and regular watering. The new growth will produce blooms in autumn.
Roses will also produce new growth, known as ‘water shoots’ from the base of the plant. These red, succulent shoots renew the plant and should not be pruned. Do not confuse water shoots with suckers, which are growth from the understock of grafted roses and which should be removed by cutting off at its base. Distinguish the two forms of growth by noting where the shoot is coming from (below the graft is a sucker, above the graft is a water shoot), its colour (water shoots are usually red), and thorns (suckers are usually thorny and give rise dark crimson red flowers that bloom only in spring).
Winter, when roses are dormant, is the time to hard prune roses cutting them back by around a third. Tall and vigorous rose varieties can be cut back even harder. This winter prune encourages new growth and strong flowering. Winter pruning can be done in July or early August depending on local conditions. Leave pruning until late winter in frost-prone areas, but in warm and coastal climates it is safe to prune roses in mid-winter (early July is ideal).
With the winter prune, aim to cut roses back to a framework of three to five strong stems by removing old stems (three years and older) at their base. Use a pruning saw for this task. Also cut out diseased growth, crossing stems and inward facing stems to open the centre of the bush. Always cut back to just above an outward-facing node to encourage the desired open bushy shape.
If roses are still flowering at pruning time, despite it being mid-winter, just cut off the flowers. They'll make a beautiful display in your home!
Use sharp, clean secateurs for pruning, sterilising tools between plants to avoid spreading any disease. Growth that is too thick for secateurs can be pruned with loppers (geared or ratchet pruners make the task easier). Vigorous thorny ground cover and hedge roses such as Flower Carpet roses can be pruned with shears or a hedge pruner. Click here to learn more about choosing the right tools for the job.
The exception to the hard winter prune is old-fashioned and species roses that only flower in spring. These are pruned if needed after flowering in late spring or early summer. With climbing roses, leave the framework of climbing branches but cut back long growth to encourage new shoots. From time to time, to renew the plant, remove the oldest canes cutting at their base. Follow up pruning of climbing roses by regularly tying in new growth. Train new growth horizontally to encourage more flowers.
As roses are thorny, wear gloves when pruning roses to avoid damage to your skin. The clean up after pruning is important. Always gather up all prunings and dispose of them in the rubbish bin. Also pick up fallen leaves to reduce the spread of disease.
After pruning and before new growth appears, spray roses with lime sulphur to control pests and diseases while they are dormant. You should also remove old mulch and spray the soil around the base of the plant.
Common pests and diseases and how to manage them
There are a lot of pests that like roses as much as we do. Here are some you may discover on your roses, particularly in spring and summer.
- Aphids attack new growth and buds and often cluster thickly on shoots. Squash, hose off or use an organic pesticide such as Yates Nature's Way Citrus & Ornamental Spray (spraying late in the day when beneficial insects such as bees and hoverflies are not about). Note: ladybirds and their larvae, other beneficial insects and small birds provide a natural control for aphids. Click here to learn more about ridding your garden of aphids.
- Scale forms clusters of white or brown lumps on stems. These are best controlled with the winter lime sulphur spray or by pruning off badly affected growth.
- Possums can do a lot of damage to roses, particularly to new growth and buds. Try preventative sprays and blocking access to plants. Covering plants at night can also deter possums while the shoots or buds mature. Always remove covers during the day. Having possum issues? Click here to read more about deterring them from your garden!
- Other insects that attack roses include grasshoppers (control by catching them in the cool of the morning) and Fullers rose weevil, which often feeds at night chewing leaves and buds. Thrips may also attack blooms especially in hot, dry weather (prune off and bin affected flowers). If you notice rose leaves with crescent shapes cut from them, don’t panic. A leaf-cutting bee has been visiting the plant. This insect isn’t considered a pest and rarely does much damage, so no control is needed.
- Black spot is a disease that affects many roses, particularly during humid weather. Roses that are badly affected can become defoliated. Black spot fungicides are available (in ready-to-use or concentrate forms) to apply to susceptible plants - Flower Power recommends Yates Rose Shield. To reduce the disease, regularly remove leaves showing black spots or yellowing (bin them, don’t compost or leave on the ground to avoid spreading). Minimise the conditions black spot thrives in by avoiding over-planting beds with roses in them to encourage good air circulation. You should also grow roses in full sun and give them regular water and fertiliser.
- Other fungal issues include powdery mildew, which affects roses that are growing in overly shaded positions or that are stressed through overcrowding or lack of water and fertiliser. Remove badly affected foliage and apply a registered fungicide. Balling or mould may also affect buds and blooms causing them to brown. Simply remove damaged buds.
Now that you know everything you need to about caring for your roses, it's time to choose your perfect varieties! Click here for a few things to consider, then dive into Flower Power's extensive range of stocked roses here.