Q Can you tell me more about rose rust?
A Rose rust (Phragmidium tuberculatum and P. mucronatum) is becoming more widespread, but is still commoner in the south and west of the country. It is less of a problem than blackspot or mildew.
Rust may appear as small, bright-orange powdery bumps on the underside of the leaf. However, this early stage of the disease is often overlooked, and it is not noticed until later.
Yellow-orange pustules appear in late summer on the undersides of the leaves, often matched by yellow spots on the upper surface. The pustules then turn black, and the whole leaf may die and fall early.
Caption: The yellow-orange pustules of rust appear in late summer
Q How does rose rust spread?
A The spores overwinter mainly on fallen leaves and are spread to the new leaves in spring by rain splash or on the wind. Some spores may also survive on other debris, on shoots and in the soil.
Q How do I control rose rust?
A Look out for the bright-orange spots early in the season, and remove affected leaves. Collecting up fallen leaves in autumn is also worthwhile.
Q What fungicide for rose rust treatments are there?
A You could use Roseclear Ultra or Bayer Garden Systhane.
Q Are there any rose varieties resistant to rose rust?
A No rose variety is immune to any of these diseases and, in a bad year, all may succumb. However, many roses show some degree of resistance, though this can vary from area to area as strains of fungus differ around the country. Nowadays, all new roses are trialled for disease resistance, and the most susceptible should not be marketed. Consequently, rose varieties less than five years old are likely to be relatively disease resistant. However, given that disease resistance can break down quickly in some roses, varieties known to be resistant may be a better bet. The roses listed below, are all tried, tested and widely available.
Widely available rose varieties that are resistant to rose rust
Short varieties (up to 70cm)
'Amber Queen' (amber yellow)
'Dawn Chorus' (orange)
'English Miss' (rosy blush)
'Korresia' (bright yellow)
'Queen Mother' (pink)
'Sexy Rexy' (rose pink)
'Sweet Dream' (apricot)
'Trumpeter' (bright vermilion)
Medium varieties (70-100cm)
'Deep Secret' (deep crimson)
'Fellowship' (deep orange)
'Just Joey' (coppery orange)
'Many Happy Returns' (blush pink)
'Tequila Sunrise' (yellow/scarlet)
'Remember Me' (coppery orange/yellow)
'Royal William' (deep crimson)
'Silver Jubilee' (coppery pink/peach)
Tall varieties (over 100cm)
'Alexander' (vermilion red)
'Graham Thomas' (deep yellow)
'Felicia' (pink/pale edge)
'Gertrude Jekyll' (pink)
'Heritage' (pale pink)
'Iceberg' (white)
'Mary Rose' (rose pink)
'Scabrosa' (purply pink)
Climbers
'Compassion' (pink/apricot)
'Dublin Bay' (deep red)
'Dortmund' (red, white eye)
'Golden Showers' (golden yellow)
'Mme Alfred Carriere' (white)
'New Dawn' (shell pink)
'Penny Lane' (champagne buff)
'Warm Welcome' (orange red)
Caption: 'Warm Welcome' has resistance to rose rust