JUNE AND JULY are planting months.
Prepare the garden bed well in advance of planting. Send away for new season rose catalogues and order the roses you want. After collecting your new roses keep the plants in a cold place until ready to plant. Just before planting remove the wrapping and place the roots into a bucket of water for at least 1 to 2 hours to be sure the roots are very wet. Meanwhile dig the holes. Place the roots onto a mound of crumbly soil at the base of the hole. Do not apply fertiliser at this time, the plant is dormant and cannot take up the fertiliser so of no benefit, also the fertiliser may burn the roots. If soil was well prepared earlier no more fertiliser is necessary. Back fill and press firmly in, follow with a thorough watering to remove any air pockets in the soil. Cut back the branches by half to encourage basal shoots. This is important.
When planting Standards place the stakes in the bed first and plant the rose touching the stake. To prevent sunburn on the young stem next summer let the stake take direct sun (usually west) with the rose stem on the shaded side. Tie with stocking or tape or something strong but soft.
JULY is work month with pruning in most districts. Frost areas wait until August.
Pruning may look rather daunting so consider one of these three methods of rose pruning which will all give good flowering results next spring.
Floribunda roses are better if pruned lighter than Hybrid Teas for the flower display is paramount in this group. Remove 1/3rd to ½ of the growth all over in a ‘topary ball’ manner. Leave many branches, don’t thin out too much (will not matter if branches cross over), don’t open up the centre of plant as will leave a ‘hole’ in the ball. Most varieties available have cluster flowers so look stunning when pruned this way.
Shrubs (includes Austin roses) need only a minimal pruning. Thin out the oldest branches, lightly trim all over the bush removing 1/3rd off the height.
Teas, Bourbon, China, Hybrid Perpetual, are all pruned very lightly (similar to shrubs) and not as for modern roses. If possible attend pruning classes.
Climbers and pillar roses do not need much pruning for their first 3 or 4 years. It is also quite usual for a newly planted climber NOT to flower in the first 12 to 18 months, but it must be growing strong new canes (branches) which will produce the flowers next season.
Use every long cane they produce to fill the space needed. Tie branches in place. Remove finished flowers. Over the years, if the climber becomes too large remove the oldest canes down at ground level and replace the space with a younger cane.
Remember flowers are produced on mature branches from the previous year’s growth, so do not cut a climber back like a bush or the result will be no flowers for another year.
Spring flowering bushes and ramblers like the banksia, laevigata, Albertine, etc, also species, gallicas, albas, damasks, etc. only flower in spring so do not prune until after they have flowered in November or December. Give a light trim over rather than a heavy prune. Removing oldest branches if becoming too tangled.
After pruning rake up most of the old leaves (mulch will cover any left). Spray plants thoroughly with Copper Oxychloride, or Bordeau Mixture, or White Oil, or Pest Oil to clean up blackspot, mildew or rust spores remaining over winter. Do this before any new leaf growth appears.
AUGUST is fertilising and mulching. Late in August or early September apply Neutrog ‘Sudden Impact for Roses’. Follow by mulching the rose beds before new shoots are too well advanced. Use lucerne hay, pea or bean straw, Johnson’s Mulch, green waste, bark, or woodchip.
Much is written in magazines on correct methods of pruning but there is no wrong way. It is better to have a go than not prune at all. Mistakes are not fatal for the plant, it will recover very quickly and you will learn with experience. Give it a go and you will be pleased with the result.
SPRING is a delightful time, roses are bursting with new growth, full of buds showing promise of a glorious display after the long cold winter. If we have another very hot summer a few tips will help plant survival.
SUMMER
This spring has been one of the loveliest rose seasons for many years. The long wet winter and cool spring has kept the roses in bloom far longer than usual. With no extreme heat to spoil the flowers, even pests and diseases have been easier to control. Black spot, mildew and rust is now showing while there is more humidity in the air, but as warmer weather follows most of these can disappear.
The spring flowering began with a profusion of ‘Gold Bunny’ - absolutely beautiful, then followed ‘Iceberg’ in almost every garden in massed displays, now ‘Bonica’ - always late to flower but worth the wait with millions of blooms. I must admit this is my favourite rose! Many gardens have an outstanding vivid red, often as standards or hedges which is most likely the stunning ‘La Sevillana’.
What to watch for in summer was reported in the last Bulletin cultural notes, so check through these points as reminders. In brief - water once a week slow and deep, remove finished flowers by cutting off with a stem (as if picking a bunch) to keep the bush tidy and quick to repeat flowers. Do not remove flowers from the Rugosa or Species, which produce hips (seedpods) and are a feature of these roses.
Spring flowering heritage roses like gallicas, damasks, albas, and species are lightly pruned or trimmed now. Don’t be too drastic as the branches can be sunburnt in summer.
Late in summer into autumn the climbers will produce their long canes, so tie them lightly to the frame or onto older branches until winter, then the canes will be hardened off and can be placed in their permanent position.
If severe heat is forecast give plants a deep watering a few days before to build up good water reserves in the plant. Mulch will keep the root zone cooler.
Spider mites (two-spotted mite) are already showing on plants in hot dry areas – pots on verandahs, bushes along paving or gravel paths, reflective heat off fences or walls. Limp pale leaves and fine webs are an indication of these pests. Spray water over the foliage in the mornings (this allows foliage to dry off through the day) for 3 or 4 days straight to upset the mites breeding. A simple remedy which works.
Roses give us enormous pleasure with an abundance of colour and fragrance all through the garden. Enjoy wandering among these lovely flowers in the cool of the evening - it is good therapy.
AUTUMN
March, April and May is the loveliest flowering time. We have all had wonderful rain which has been of great benefit to the gardens. New growth is emerging almost over-night which may bring early flowering on some roses.
Watch for fungal diseases - black spot, mildew and rust on the new leaves. It is wise to keep under control if possible. For all fungal problems use Triforine which is systemic with longest protection, or Mancozeb Plus on a 2 to 3 week timetable (don’t use this spray prior to the rose show as a residue is left on the leaves), and for Mildew a milk spray. The latest information on milk spray is to use it as a preventative on a weekly basis. Spray well into the bush and try to coat all leaves to the point of ‘run off’. 1 part milk with 9 parts water is the quantity and it does not matter what type of milk so perhaps keep a tin of powdered milk handy.
Aphids may become active on the new shoots but the predator wasp, ladybirds, and birds will do a good job of control. If thickly on the buds squirt them off with a jet of water. May need to do this two or three times to reduce their numbers before the predators take over. Even a spray with soapy water or pest oil will help. Don’t use winter oil as can burn the leaves, keep this for after winter pruning.
Keep up with regular watering even though we had rain, the soil can quickly dry out. Potted roses must still be watered daily. Also if water runs out of the pot very quickly consider it is not soaking into the potting soil. Test with a finger into the soil and if still dry add a water wetter additive (Saturaid, etc) to the watering can. Only needed once or twice through the summer but allows the water to soak into the potting soil more effectively.
Perhaps consider this is the year for garden recovery and replanting. Now is the time to order your roses and then prepare the rose bed. Turn over the soil with the addition of compost and Neutrog’s ‘Seamungus’ is ideal, also cow manure is good and fork through the soil 6 to 8 weeks before planting. If soil is a high pH or alkaline soil add some sulphur and animal manures. If very sandy soil add as much organic material as possible - leaves, compost, mulch, animal manures, ‘Seamungus’, etc to breakdown and help absorb more moisture in soil next summer. If unsure of soil pH take a small soil sample to your friendly nursery for testing, or buy a soil testing kit (about $28.00) then you can identify your soil type and rectify any problems.
If replacing one or two roses soil removal is necessary - two to three buckets of soil (or half a barrow load). Place this ‘old’ soil elsewhere in the garden as is still good soil. Replace with fresh soil from another part of the garden, with the addition of compost or Seamungas forked altogether. Re-planting can be immediately.
For a larger bed of roses, remove them now. To remove large quantities of soil is not practical so fork into the soil all you can find of leaves, compost, mulch, animal manures, ‘Seamungas’, etc, but delay planting until at lease 3 months has elapsed to allowed all old roots to compost down. Planting can be as late as August but order your roses and ask they be held until later.
When picking roses, particularly for decorating at the Rose Shows pick blooms in the cool of the morning or evening, take a bucket of water with you to place the flowers into. Give a good drink for several hours and they will keep longer in the vase. A good idea is to recut the end of the stem to allow more water take-up in the vase. During the show spray the petals with a fine water mist as the blooms can get very dry and lose their freshness. Keep up with removal of finished flowers from the bushes to encourage more blooms
‘Lorraine Lee’ and ‘Nancy Hayward’ roses flower in winter so must be pruned early in March or April. This produces new growth for flowers in June onwards.
May will still have many lovely blooms. Foliage is changing colour to autumn tints, hips (seedpods) are colouring up, particularly species and shrubs. Don’t remove these hips, as they will stay on the bush well into winter to add a touch of colour in the garden. Also you can gather these hips in July and try to raise some new roses by seed.
Roses that don't thrive, are stunted or struggling.
· If a new plant is slow to start, form a mound of light soil, old leaves, compost or potting soil to cover the bud union of the plant by about 10-15cm (6 inches). This will help to draw new shoots from the bud union.
· Planted into an old rose bed. After the removal of old roses the bed should be rested for 9 to 12 months, or, exchange half-barrow of soil with fresh soil from elsewhere in the garden - for each new plant.
· Sandy soil. Add plenty of organic material, and water more often. Check water is penetrating the sand, if not, use water wetting agent, eg Saturaid.
· Too close to robbing tree or shrub roots, or closely surrounded by lawn.
· Cold draughty position - provide windbreaks.
· Barren soil, lacking nutrients and organic matter. Improve the soil with any organic mulch (lucerne hay, Pea-straw, grass, seaweed, leaves, old animal manure, mushroom compost) and fertilize with 'Sudden Impact for Roses'. Earthworms will work the soil for you.
· Nematodes (eelworms). Most prevalent in sandy soil; have soil tested and possibly chemically treated. Seek professional advice.
· Waterlogging (rare in SA). Raise the soil level in order to shed water, divert flood water or install underground drainage.
· A stunted plant, even if several years old, may still be satisfactorily transplanted in winter. Prune and remove all leaves, then plant as for a new plant.
Established Roses that die back. 'Dieback' is not a disease in itself but a symptom of several possible causes:
· Most rose varieties, especially yellow and bronze colours, produce a certain number of 'dieback' branches as a normal habit of growth.
· Severe mildew, blackspot or rust diseases can cause leaf drop exposing the branches to possible sunburn. Control with 'Triforine' or 'Mancozeb Plus' if severe. Milk spray is also worth using.
· Sunburn. Can 'ring bark' the branch, cut back below the affected area. Mulch well over the bud-union for protection. Watch the trunk of standards from radiating heat off paving or fence. Place the stake on the hottest side to cast shadow on the stem.
· Check if ties have choked the branch, particularly climbers and standards.
Roses with unhealthy leaves. Leaves can tell the experienced grower a tremendous lot about the health of a plant. It is normal for a few lower and inner leaves to constantly be turning yellow or brown and dropping, especially following long spell of hot weather.
Random patterns:
· Mildew - white powder on buds and young leaves. Spray with milk - 1 part milk to 10 parts water.
· Black spot - random black blotches with yellow over remainder of leaf. Spray with fungicide.
· Rust - rusty pustules or specks underneath the leaf, green spots on the topside. Spray Triforine.
· Sunburn - dry brown edges to leaves. Will not recover. Keep up with deep watering.
· Normal aging and dormancy.
More or less symmetrical patterns:
· Nutrient problems - bronzing, yellowing, veining and dead margins on tips all suggest feed problems. Apply 'Sudden Impact for Roses', may take two weeks to correct. For a quick fix but short term apply a liquid fertiliser every 7 days. Or seek expert advice.
· Yellowing with green veins - lime induced chlorosis found in alkaline soils, a form of nutrient deficiency. Have soil tested to identify the pH of soil. If over pH 8 apply Iron Chelate or liquid fertiliser regularly, for long term soil improvement add organic mulch and ½ cup sulphur scattered around each plant, water in well. Apply sulphur every three months for one year. If improvement in leaf colouring, may only need to apply once a year. Keep up the organic mulch.
· Mosaic virus - no cure but practically harmless. Does not reduce flowering nor spread to other roses. Mostly found on very old garden roses, more obvious when plants are heat stressed in summer.
· Yellowing or chlorosis - certain weed poisons. Water heavily and hope!
· Salinity - leaves of russet-brown with dead edges, and shiny salt deposit on the surface. Avoid overhead watering, use drip irrigation. Dogs repeatedly 'lifting their leg' on a plant can have the same effect. Bore water with high salt content can be a problem in country areas. If only available water flood irrigate the roses deeply, and water only to keep the plants alive until autumn rains. Mulch very deeply.
Gnarled leaves:
· Damage by aphids while the shoot was forming, resembles peach 'curl leaf', will grow out of it.
· Thin grotesque shapes - hormone weedicide damage, eg. glyphosate.
Flowering
· Coarse, split or balled blooms: Excessive fertilizing, hard pruning, unsuitable variety.
· Small blooms or few petals: Unthrifty soil, pruned too light or no pruning, unsuitable variety, hormone weedicide if linked with distorted leaf growth.
· Lack of blooms or 'blind' shoots: caterpillar or early aphid damage, excess nitrogen, or deficiency of potassium fertilizer, or too shady. Some seasons 'blind shoots' appear for no apparent reason, very frustrating. Trim off the tip of the stem and new flowering shoots will follow.
· Damaged blooms - thrip, caterpillar, grey mould (botrytis), possums, earwigs.
Climbers that won't flower.
· Usually caused by pruning a vigorous climber back to a smaller size, thus cutting off the potential flowering shoots. Allow it to grow to its full size by extending the climbing trellis.
· 'Sported' climbers which derive from bush varieties sometimes take a year or two to start into climbing growth. They must be given regular water and fertiliser to bring them into maximum growth initially.
· All 'natural' climbers eg 'Pierre de Ronsard', 'Blossomtime', 'Altissimo' must climb unless they are grossly stunted.
It is quite usual for newly planted climbers not to flower for 12 to 18 months. They must produce strong canes in their first summer and autumn. Flowers follow in spring. Do not prune climbers for 3 or 4 years.
Maureen Ross
CULTURE NOTES
for Winter, Spring, Summer and Autumn
and some Problem Solving Tips