Rose Mainzer Fastnacht

A classic lavender Hybrid Tea rose introduced by Mathias Tantau Jr. in 1964. Famed for its unique silvery-lilac blooms and intense fragrance, it set the benchmark for “blue” roses for decades. It gained worldwide popularity for its unique silvery-lilac flower coloration and strong fragrance, traits that were and remain uncommon in roses. Its introduction expanded the palette of Hybrid Teas into the elusive “blue” range (mauve/lavender), fueling both consumer intrigue and further breeding of “blue” roses. The cultivar has been commercially successful as a garden rose and florist’s rose. For many years it was a top exhibition rose in its color class and is still grown in private and public rose gardens globally.

DESCRIPTION OF THE VARIETY

FLOWERING

‘Mainzer Fastnacht’ is a repeat-blooming (remontant) rose. It generally has an initial heavy bloom in early summer (June in temperate Northern Hemisphere climates) followed by periodic blooming every 6 - 8 weeks in a rhythmic cycle if spent blooms are removed (deadheaded) timely. Each flowering stem usually carries a single bloom (one per stem is the definition of the Hybrid Tea class), though side buds sometimes develop, usually up to 5- 7 blooms together. To get exhibition-quality single blooms, side buds should be removed early. The cultivar’s repeat is reliable but not rapid, it is known for having a bit slower rebloom cycle compared to more modern reblooming varieties. Nonetheless, given proper care, it will flower in flushes throughout the season until frost.

The blooms of ‘Mainzer Fastnacht’ are large, the diameter averages about 12 cm (4.5 inches) when fully open. The flower shape is a very traditional Hybrid Tea high-centered, typically borne singly on long stems. The flowers are very double, the petal count is in the high twenties to 40. The petals form a spiraled high point at the center in the classic exhibition style. Buds are elegant, long and pointed, with a slender ovoid shape before opening. The flower color is its signature feature: a silvery lavender or lilac mauve, sometimes also described as cold, pale lilac shade, sometimes warmed with a little pink. The blooms may appear more blue-toned in certain lights or cooler weather; indeed, sunshine brings out the blue tones in the petals. The reverse of petals is often slightly paler, contributing to a silvery sheen.

As most “blue” roses the petals of this rose variety may suffer from sun damage when grown in full sun in climate with scorching summers, therefore in such regions it requires a place with shade protection in most hot hours of the day.

Fragrance:

The fragrance is pronounced, often described as strong, sweetly Old rose perfumed with a spicy or citrus hint. For instance, Rosen Tantau notes a “spicy, outstandingly strong, fresh” scent. Gardeners generally agree on its intensity. In any case, this rose variety is frequently listed among the more fragrant Hybrid Teas, making it as valued for its scent as for its color.

PLANT
The rose variety ‘Mainzer Fastnacht’ is classified as a Hybrid Tea rose. It is often also categorized as Modern large-flowered shrub rose as it is bearing high-centered exhibition-style blooms. It forms a medium sized, upright and slightly outwardly bush, reaching to about 90 - 130 cm (3 - 4 ft) in height and of about 60 cm (2 ft) in width, In ideal conditions it can grow up to about 150 cm (5 ft) tall.

It tends to shoot with few strong basal canes, and the plant has a somewhat open habit of growth if unpruned. New growth has a red tint and the mature stems have medium green colour with strong grayish tint. There are rather few prickles present on the basal canes and on the lateral branches of this rose variety, the prickles are long, sharp and have a pyramidal shape. The young prickles have reddish colour and mature to grayish brown colour.

This rose is excellent for getting cut flowers - the long stems, high-centered blooms look absolutely stunning in vase and also was grown for exhibition. This rose is equitable for planting in rose beds, small groups for color impact, or mixed borders (best with care due to color). For best flowering and color it requires a full sun display with 6+ hours of sun per day, however it requires shade in scorching climates. It tolerates light partial shade well, and even appreciates it in hot regions, but with reduced blooms and higher disease risk if too shaded. Remember that for roses morning sun is important to dry dew.

Foliage:

The plants of this rose variety have a normal quantity of the foliage, typical for Hybrid Teas. The number of leaflets on normal mid-stem leaves varies from 5 to 7, including the terminal leaflet. The foliage has medium green to dark green, when young the foliage has a bronzy tint which changes to slightly silvery when leaflets mature. The shape of the leaflets is pointed oval, the shape of the leaflet tip is acuminate and the base shape is rounded. The surface texture of the leaflets is leathery, semi-glossy. The edges are serrated, the type of serration is rather small and mostly double.

Disease resistance:

The rose variety ‘Mainzer Fastnacht’ has average to good resistance to black spot - it can get black spot in humid climate, but many reports of relative resilience (suitable for ADR 1964). The powdery mildew is generally a minor issue, the mildew resistance fairly good, especially in UK. The resistance to rust is good, most commonly it is not affected with this disease, although some gardeners report some susceptibility in conducive conditions. Overall this rose requires preventive care for best foliage health.

The new tender growth attracts aphids, common in spring. The highly fragrant and tender blooms are susceptible to thrips which leads to petal browning. In some regions, Japanese beetles devour blooms and make holes in leaves. Spider mites appear on plants in hot dry climates which is common for all rose varieties.

‘Mainzer Fastnacht’ is recommended for growing in climates rated as USDA Zone 7b ( -12°C) and warmer with no winter protection and in zone USDA 6 or similar needs heavy mulch and is likely to get a cane dieback. In climates similar to USDA zone 5 is survivable with significant protection (e.g., insulated cover or lifting). In mild climates it is winter hardy. Prefers warm summers but not extreme heat. In hot climates, blooms can “ball” or scorch; provide afternoon shade if temperature gets warmer as +32°C. Performs well in warm-summer continental and Mediterranean climates and requires extra care in tropical heat.

The cultivar’s original name is German ‘Mainzer Fastnacht’ translates to “Carnival of Mainz” or “Mainz Mardi Gras”. This name was chosen by the breeder Mathias Tantau Jr. to honor the famous carnival festival in the city of Mainz. As noted in a French rose encyclopedia. Mainz’s carnival is a well-known cultural event (Fastnacht being the Rhineland word for the pre-Lent carnival), hence the name evokes festivity and perhaps the rose’s joyous display of color. Interestingly, in the same region, Reimer Kordes independently bred a lavender rose in 1964 which he named ‘Kölner Karneval’ (Cologne Carnival), indicating a coincidental thematic overlap in naming by two German breeders celebrating two city carnivals. This likely contributed to later confusion in the English-speaking market between the two “Carnival” roses.

‘Mainzer Fastnacht’ has been marketed under several synonyms internationally, which is common for roses to suit different languages and trademark situations. The official cultivar code is TANnacht, denoting Tantau’s naming convention.

“Sissi” - used in France (named by distributor NIRP in 1964). The choice “Sissi” likely alludes to Empress Elisabeth “Sisi” of Austria, a figure romantic in Europe, but it was a short, catchy name. However, in English “sissy” is a pejorative term, so this was not suitable for anglophone countries.

“Blue Moon” – the name adopted for English-speaking markets starting sirca 1965. The change was prompted by the issues with “Sissi” noted above. The “Blue Moon” name emphasizes the rare color (as in the idiom “once in a blue moon”).

“Blue Monday” – a synonym reported in some references. Blue Monday appears to be an English-translated variant of the Swedish name (see next) or possibly used in some catalogues in the 1960s. It is not as prevalent today, but older literature lists ‘Blue Monday’ as an alternative name.

“Blå Måndag” - the Swedish name, literally “Blue Monday” in Swedish. This was used in Scandinavian countries to market the rose, maintaining the “blue” theme.

“Mainzer Rad” - German for “Wheel of Mainz.” The wheel is a symbol on the coat of arms of Mainz (the Mainzer Rad is iconic locally). This synonym might have been used in some German regions or catalogs, possibly to avoid confusion with the event name or for a local twist.

“Navo-Rose” – a more obscure synonym; it appears in some listings (e.g., in the Monaco Nature Encyclopedia) but is not widespread. It may have been a temporary trade name or a code used by a nursery consortium.

Beyond the 1964 RNRS Certificate and ADR designation, ‘Mainzer Fastnacht’ achieved other honors indicative of its quality. It won a Certificate of Merit in the Royal National Rose Society’s trials the year prior to its commercial release, attesting to its performance under UK conditions. The German ADR trials of the 1960s focused on garden performance (including disease resistance), and ‘Mainzer Fastnacht’s success there suggests it had above-average tolerance to black spot and mildew at the time. However, it did not receive an All-America Rose Selections (AARS) award in the United States; its reception in North America was respectable but somewhat tempered by the challenges of growing Hybrid Teas in colder climates. The climbing sport of this rose (‘Climbing Mainzer Fastnacht’, introduced later) also garnered attention, though it is less common now. Overall, ‘Mainzer Fastnacht’ is widely regarded as a milestone cultivar bridging novelty in color with classic form and fragrance of the Hybrid Tea roses.

ORIGIN OF THE VARIETY

Rose variety ‘TANnacht’ / ‘Mainzer Fastnacht’ was bred by Mathias Tantau Jr. in Germany and introduced in 1964. This rose derived from the crossing lavender Hybrid Tea rose ‘Sterling Silver’ by Fisher, 1955 with an unnamed rose seedling. There has been some historical question about the exact seed parent or pollen parent, but consensus (as published by the RHS and others) is that ‘Sterling Silver’ was used (likely as seed parent) and the other parent was an unnamed seedling from Tantau’s breeding line.

SUMMARY OF THE VARIETY

‘Mainzer Fastnacht’ and its wide introduction across continents in the 1960s established it as one of the era’s most internationally recognized roses. Breeding records and cultivar registries consistently affirm Tantau’s role and the ‘Sterling Silver’ lineage, which is important for historical accuracy and understanding the rose’s characteristics (e.g., why it has exceptional fragrance - likely inherited from ‘Sterling Silver’, described in literature as having a powerful scent). ‘Mainzer Fastnacht’ earned early acclaim in competitive trials: it received a Royal National Rose Society (RNRS) Certificate of Merit in 1964, the year of its debut, and was designated an ADR rose in 1964 (Allgemeine Deutsche Rosenneuheitenprüfung), indicating superior garden performance and disease tolerance under German trial conditions according to the German Rose Society’s Rosenwelten compendium, underscoring its significance as a benchmark “blue” rose in the mid-20th century.

USDA 7