How-to Guide to Organic Roses

Despite the fact that roses have a reputation for being high maintenance, most gardeners would not be without them. The combination of beauty, fragrance and the nostalgia they evoke will always assure them a place in the garden. But the trick to enjoying roses is learning how to grow them without the ravages of black spot, powdery mildew, aphids, whitefly and rust.

The best way to avoid problems is to research a rose before planting it, but once smitten even a bleak history may not be enough to deter us! If you are a busy or novice gardener I recommend rugosa roses. They are the least prone to problems with insect and diseases, and I’d go as far as to say they are almost trouble free.

Rosa ‘Roseraie de l’Haÿ’ (zone 4) provides a superb centrepiece for my vegetable garden. I have to prune it a lot, but perfume from non-stop blooms is well worth the effort. Besides, I really enjoy pruning roses. David Austin’s English roses are the next easiest to grow, with the perfect combination of old-fashioned beauty and repeat blooming. Why settle for just one magnificent June flush when you can have an ongoing show of lovely roses?

I do make exceptions, however. Along my 15-metre (50-ft.) arbour are climbers that have a single burst of bloom in June. ‘Amaglia’ (a sport of ‘Kiftsgate’) deserves its place of honour at the head of the arbour. The first time I saw this rose it took my breath away. ‘Veilchenblau’, a spectacular true blue rose is a beautiful companion. ‘American Pillar’ is a vigorous rambler that puts on such a gorgeous display of single roses it has become one of my favourites.

Organic gardening methods are perfect for roses. The three worst plagues – black spot, powdery mildew and rust – are all fungal diseases spread by spores, which can remain dormant in soil and on leaves for years. Feeding the soil with natural mulches (aged manure, compost, seaweed or leaf mulch), smothers any spores that may be in the soil and prevents them being splashed back onto roses by rain or watering.

My motto is “to prevent disease, remove disease,” so I rake fallen leaves from underneath roses in late fall and strip any remaining leaves off the plants. This helps prevent the spores from overwintering. In early spring, before bud break, I smother any that may have overwintered on the plant by spraying stems with dormant lime sulphur/oil spray.
 

TIP: Spray your fruit trees at the same time using this recipe:

Dormant Lime Sulphur/Oil Spray

In a 3-litre pressure pump sprayer mix: 1⁄4 cup (60 mL) horticultural oil 1⁄2 cup (125 mL) lime/sulphur Add 3 litres (quarts) water.
 

TIP: Roses love banana peels!

Compost banana skins around your roses. Bury three cut-up banana peels around each bush. A banana peel contains a lot of phosphorus (3.25 per cent) and potash (41.76 per cent), which really gets roses blooming.
 

TIP: When spraying plants growing against a wall or other structure, cover the wall with plastic sheeting, as sulphur stains.

Cover foliage plants in the spray zone with plastic to prevent damage.

Continued next page: Pruning and fertilizing roses, plus recommended roses to grow
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Pruning Roses

I got hooked on roses the first time I gave a bedraggled overgrown climber a heavy pruning and was rewarded by an exquisite show of blossoms. I spent the next few years perfecting my pruning technique – and because roses need annual pruning I had plenty of opportunity to practice.

Always remember the 3 Ds: remove dead, diseased and damaged branches first. Then remove spindly and crossing shoots. The aim is to maintain a framework of vigorous healthy canes. With hybrid teas and floribunda roses, cut back annually to the strongest set of canes, and reduce these by two-thirds, removing one-third in fall and one-third in spring.

Prune rambling and climbing roses to leave only the strongest canes, from which the most vigorous shoots will grow. Ramblers are the best choice for growing on fences or for scrambling over trees or hedges. Climbers, which maintain a more manageable framework, are a better choice for planting over arches and pergolas. Climbing roses flower more profusely when the main growth is tied down horizontally, which encourages the growth of flowering laterals.
 

Fertilizing Roses

I used to be head gardener at Point Ellice House, a restored Victorian garden where the O’Reilly family had planted over 80 heritage roses. Here I discovered the secret to beautiful roses: feed them well. Roses are heavy feeders that flower much more prolifically when adequately nourished. Try this simple, inexpensive, homemade recipe; it makes an amazing difference.
 

Organic Rose Fertilizer Recipes

Before blooming:
1 cup (250 mL) alfalfa pellets 1⁄4 cup (60 mL) rock phosphate 2 Tbsp. (30 mL) magnesium sulphate (Epsom salts)

Combine and mix well. Scatter around the drip line under your rose bushes and work in gently.

After blooming (and no later than the end of August):
1 cup (250 mL) alfalfa pellets 2 Tbsp. (30 mL) magnesium sulphate 2 gallons (8 litres) water

Mix together and steep for 24 hours.

Use mixture to water the root zone of each rose bush.

Recommended Roses:

The following plants are hardy to the zone number indicated:

Climbers:

• Rosa ‘Aloha’ – zone 5
• R. ‘Iceberg’ – zone 5
• R. ‘Mme. Alfred Carrière’ – zone 6
• R. ‘New Dawn’ – zone 5
• R. ‘Royal Sunset’ – zone 7

Ramblers:

• R. ‘Amaglia’ – zone 6
• R. ‘American Pillar’ – zone 5
• R. ‘Kiftsgate’ – zone 4
• R. ‘Paul’s Himalayan Musk’ – zone 6
• R. banksiae ‘Lutea’ – zone 8
• R. ‘Veilchenblau’ – zone 5

Carolyn Herriot owns The Garden Path Centre for Organic Gardening in Victoria (www.earthfuture.com/gardenpath) and Seeds of Victoria. She is author of A Year On The Garden Path: A 52-Week Organic Gardening Guide (ISBN 0-9738058-0-3).