Rose Care & Pruning

Rose Types

Roses are the world’s most popular flower and a quintessential part of many gardener’s homes. With several different categories containing thousands of different cultivars, there’s a rose for everyone.

The following is a breakdown of the most common rose terminology used:

• Species – wild roses, tend to be quite thorny and have a shorter flowering window in early summer.
• Heritage or Old Fashioned – The oldest roses bred by man prior to 1867. Often characterised by very large, full quartered-style blooms with intense fragrance.
• Floribunda – modern rose class with flowers that produce in clusters on a single stem.
• Hybrid Tea – modern rose class with larger flowers on sturdy, single stems. Ideal for picking for use in bouquets.
• Standard – grown to produce a head of foliage and flowers atop a single tall, straight, bare trunk.
• Climber/Rambler – rose with long stems that can be trained up a frame. Can grow up to 10m in some types.
• Bush – traditional bush-shrub plant. Usually grows between 1-3m.
• Miniature – dwarf plants with small flowers. Often growing between 30-50cm.

Planting

Choose a position with full sun – between 6-8 hours a day. Light shade can be beneficial for protection from the extreme heat of the summer afternoon. Shelter from strong winds. Rose plants themselves are relatively hardy to wind, but the delicate blossoms will take the brunt of a storm leading to a minimal or broken display.

In terms of timing, the winter months are the best time of the year to be planting roses. With the new supply of roses in the stores and in their dormant state, planting them now will mean they establish their root systems over the cooler winter months ready to put on strong growth in spring. Roses can be planted out any other time of the year, but with more care to ensure they are well watered while becoming established.

When a rose is being planted it is generally expected that it will remain in existence for many years. The preparation of the soil is therefore important. The ground should be cultivated about two lengths of your spade blade or about 450mm. Most soils will benefit by incorporating material such as ‘Ican Premium Compost’ or ‘Tui Sheep Pellets’. The digging will open up soils, improving the general structure. In a light soil the water holding capacity will be greatly increased as the organic material can hold additional moisture. The addition of ‘Ican Slow Food’ into the hole when planting will help ensure excellent root development and growth.

Roses are never completely dormant and the less the roots are disturbed the better the plants will establish. A hole should be dug significantly large and deep to accommodate the roots when they are spread out. Make sure the roots are watered and well moist prior to planting, followed by a deep soak after planting. Be careful that no damage is done to the plants when the soil is firmed round the roots. The bud union of bush and climbing roses is left just above the ground surface.

Apply a mulch around the top after planting to lock in ground moisture. I like to use ‘Ican Premium Compost’ followed by a bark mulch. ‘Tui Mulch & Feed’ is also a fantastic option. Make sure to leave a gap between the mulch and the stem of the plant to prevent rotting the trunk.

Planting Standards

If planting a group of standard roses they should all be the same height so that they can be planted with the heads at a uniform level. It is preferable before planting standard roses to put in the stakes that will support them. This avoids damage to the roots which may otherwise occur if they are added later.

Use a soft tie material for tying standard roses. Wire should never be used and padding should be placed under a tie of twine or cord. Ensure that one of the ties is secured to its stake near the head of the rose to prevent damage or the possibility of it snapping off in strong wind.

Planting in Pots

Much like the importance of the soil quality in your garden beds, selecting a good potting mix is crucial to the success of your potted roses.
‘Ican Premium Potting Mix’ is our favourite – a high quality, bark based mix with plenty of pumice for air circulation and good drainage.

Find a large, appropriately sized pot. We recommend no smaller than 35L – approximately 35-40cm in diameter and height. A larger pot will reduce stress on the plant.

Plant with an application of ‘Ican Slow Food’. Incorporating a wetting agent such as ‘Saturaid’ to the soil will assist with even moisture distribution and slightly reduced watering requirements. Care should be taken to never allow roses in pots to dry out.

Feeding & Maintenance

Feed roses in early spring when new growth appears and again in mid-summer. Use a well balanced rose-specific fertiliser such as ‘Ican Rose Food’ for best results. For extra strong plants and increased flower production, supplement throughout the growing season (spring & summer) with some of the following:

• ‘Tui Sulphate of Potash’ provides a big potassium boost for flower production.
• ‘Ican Real Blood & Bone’ is high in nitrogen, strengthening foliage development and encourages earthworm activity in the soil for healthy structure.
• Water weekly with ‘Ican Liquid Fast Food’ for a quick boost of nutrients and flush of growth.
• Continue to regularly apply compost, sheep pellets & mulch as often as it breaks down into the soil.

For roses planted in pots, make sure to select a slow-release fertiliser appropriate for pots & containers to prevent the burning of roots.

• ‘Ican Slow Food’ is a fantastic base-food to apply long term for the general health of your plant.
• ‘Thrive Granular Rose Food’ is an excellent rose-specific, balanced fertiliser designed to release nutrients for up to 3 months.
• ‘Yates Acticote Roses & Flowers’ is a high quality fertiliser designed to work quickly, while being long lasting for up to 12 months.
• Don’t forget to water regularly with ‘Ican Liquid Fast Food’ for a quick boost of nutrients and flush of growth.

Regular, deep, weekly watering through the dry summer months will keep plants strong and healthy. When the plants are well fed and watered the incidence of pest infestation and diseases is reduced.

Pests & Diseases

Keep an eye on your roses for both pests and diseases.

Look out for aphids, caterpillars, scale, red spider mites and thrips. Common diseases include blackspot, mildew and rose rust.

The use of ‘Yates Supershield’ helps to control these problems – this is a combination systemic insect and fungus spray. A recently released insecticide that is also having good effect is ‘Grosafe Groventive’.

If you notice rose buds going brown and rotting it is quite likely to be botrytis – (brown rot) a weather-related fungi. Prevent by spraying with ‘Grosafe Free Flo Copper’ or any spray that controls botrytis and downy mildew. A systemic fungus spray that is effective for treatment is ‘Yates Fungus Fighter’.

Call in and ask at the garden centre if you want more advice. Bring some photos or samples so we can accurately identify the problem and ensure we’re giving you the right solution.

Winter Spraying

The benefit of winter spraying is that it gives your roses a head-start in Spring. A winter spraying program is important for maintaining the health of your plant while dormant, and reduces the incidence of insects during spring and summer.

End of June/Early July

• Lime Sulphur: This spray is used to induce dormancy. By doing this the rose has a proper rest period. It is the first spray to apply and has two main benefits. The first is Lime Sulphur removes lichen and moss from old roses and cleans up the over wintering bugs and diseases, provides a protective film of Sulphur over buds to prevent entry of fungus into plant. The second benefit is so you can prune it. Leave for 14 days before applying Copper or spraying Oil. See ‘Yates Lime Sulphur’.

Mid-July after Pruning (repeat at least twice)

• Copper: is applied next. Copper is a fungicide and bactericide spray. ‘Grosafe Freeflo Copper’ is a high-grade form of Copper Hydroxide that is by far the most cost-effective copper product available to home gardeners. It is a fine dispersible granule that pours and can be measured like a liquid. 5g = 5ml. Use at regular intervals, every fortnight is ideal.

Mid-July after Pruning & about 2 weeks after Copper Spray (repeat at least twice)

• Enspray 99 Oil: Apply after (or with) the Copper spray to control over-wintering scale and mites. ‘Grosafe Enspray 99’ works by smothering insects so they can’t build up immunity to it. This reduces the risk of these pests taking hold in the coming season.  If mixing with Copper, put copper in tank first & dissolve well.

Pruning

Rose pruning can be quite intimidating to some gardeners. Becoming an expert pruner does take time and experience, but be reassured, it is very hard to kill a rose through bad pruning. Roses respond well to pruning: It gets rid of old, diseased wood, tidies up the bush, improves air circulation, and stimulates new growth on which new season flowers will grow.

For some in depth advice and visual instructions, view our video on Winter Rose Pruning.

Winter Pruning

1. Pruning should be proceeded with a spray of Lime Sulphur. This should be done at the start of July. In Whanganui, rose pruning is best undertaken in the middle of July. Pruning any earlier can often result in the plant producing new growth which can be damaged by frost. When the rose has lost all its leaves, you will know the sap has settled and will not bleed from cut.

2. Your first cuts should be the removal of all dead wood, cuts should be into green wood or to nearest axis.

3. Your next cuts should be opening up middle and removing crossing branches. Choose the weaker/damaged one to remove.

4. Now what you have left needs to be shortened and tidied up, start from the crown and select a clean healthy outward facing bud about ½ of the way up and cut just less than 1cm above bud with your cut sloping away from bud.

5. Make sure there are no more than two pruning cuts per branch, keep it tidy and uncrowded at the branch tips.

The above pruning guidelines are for bush and standard roses, for climbers carry out steps 1 & 2. Then only cut back to leaders (long growth from crown), so step 3 above can be done but only as far back to leaders then carry on to step 5.  

• All suckers growing from the rootstock and below the graft (budding union) should be cut away. These will not be true to type.
• Remove any old, dead branches from the base. Cut back to green wood.
• Remove any interior branches that cross other branches, to prevent crowding.

For any large (or even small) cuts, we highly recommend applying a pruning paste immediately afterwards. Pruning pastes are sealants, acting like a bandaid for the plant, with anti-bacterial and anti-fungal properties to prevent infections from taking hold.

Plants from a garden centre or nursery have usually been cut back for the ease of handling and packing, and in some cases may require extra pruning. Early planting (around May) is recommended and pruning should be done during the normal pruning season which is best done in mid to late July for gardens in Whanganui. If roses are pruned earlier it will encourage new growth which can get damaged by frost.

Summer Pruning & Deadheading

Major pruning should be avoided during summer unless a plant has been badly damaged and needs fixing. Instead, minor trimming can be done to tidy a plant up. Primarily, you will want to be keeping a eye out to deadhead and cut away old, finished growth in small and regular actions.

Simply take a clean, sharp pair of secateurs and trim away the stem of the finished rose head to the nearest fresh bud. This will prompt the plant to push new growth out and repeat flowering.

For more detail on deadheading, view our video on Summer Rose Pruning.

Tools

It is vital to keep your garden tools clean, sharp and in good condition. Clean by wiping blades with methylated spirits. This will minimize the spread of disease between plants.  Below are the tools you need to successfully prune your roses.

Secateurs: There is a variety of secateurs out there so what to look for? You look for quality. Pick a reputable brand, they have a good guarantee  and are over all a better tool, so will last longer when treated well, also quality secateurs sharpen better. We use and highly recommend Fiskers and Wolf-garten.

• Do I need Bypass or Anvil? The main difference between these two secateurs is the Bypass blades pass one another, and the Anvils top sharp blade closes on top of the solid anvil blade using around 20% less effort to close the blades.

• And what’s up with the turning handle? To reduce strain on the hands and wrists, the Arthritis society recommends these for those of you that suffer from pain when pruning.

Loppers: Are used for larger branches up to 5cm in diameter with some loppers giving up to three more power in your cut, they are also useful for getting into the middle of a rose bush to remove branches at the crown without getting scratched up.

Wire brush: Not a well-known tool but very useful for rejuvenating old, tired rose crowns. If your rose is quite old or has lost its vigour and/or is covered in moss, then a light brush of the crown with a wire brush can encourage new growth to sprout.