Getting creative with flowering crabapple trees

Flowering crabapple trees have come a long way since Spring Snow Flowering Crabapple and Thunderchild Rosybloom Crabapple were introduced to the market more than 50 years ago.

Spring Snow was developed by Bert Porter at his nursery in northern Saskatchewan in the 1960s. A completely fruitless tree with masses of fragrant white flowers, Spring Snow became the leading crabapple cultivar in North America. Hardy to Zone 2, it grows to a height of 7.6 metres with a robust width of 6.1 metres. While Spring Snow continues to be an option for consumers who do not want messy fruit drop, it is highly susceptible to apple scab, a fungal disease that thrives in wet weather, causing premature leaf drop.

Thunderchild Rosybloom Crabapple was introduced by Saskatchewan breeder Percy Wright in 1974. Slightly smaller than Spring Snow, Thunderchild’s glossy purple foliage made it a top seller for many years. Although resistant to fire blight, a bacterial disease that causes dieback of branches, Thunderchild is also highly susceptible to apple scab.

Another older variety, Pink Spire Flowering Crabapple, is also highly susceptible to apple scab.

In the unusually wet spring of 2024, apple scab was prevalent across Winnipeg. My older generation rosybloom crabapple was almost completely defoliated that year. This year’s wet season is likely to see a resurgence in apple scab in susceptible cultivars.

In response to consumer demand for flowering crabapples that have better disease resistance, minimal or zero fruit drop and narrower forms that are better adapted to smaller residential yards, breeders have developed a new generation of columnar trees.

Gladiator Rosybloom Crabapple, introduced in 2006 by plant breeder Rick Durand at Prairie Shade Nursery in Portage la Prairie, was one of the earlier game-changers. Hardy to Zone 2, this upright disease-resistant specimen is just 2.7 metres wide with highly fragrant flowers that bloom in late May to early June. Glossy burgundy-purple leaves in summer transition to orange-red in the fall. The tiny fruit is reddish-purple.

Purple Spire Rosybloom Crabapple, introduced by Jeffries Nurseries and Bylands Nurseries, has a columnar form with a narrow width that is just 1.8 metres at maturity. It features striking purple foliage in late summer. Its medium-size fruit (2.5 cm) is shed in early fall.

Midnite Spire is another disease-resistant rosybloom crabapple with a distinctive columnar form. Introduced by Jeffries Nurseries, Midnite Spire has glossy purple foliage throughout the summer which turns yellow in the fall.

Green Wall Spire, another ultra-slim introduction, was developed by Wilbert Ronald at Jeffries Nurseries. Purple Spire, Midnite Spire and Green Wall Spire all have a mature height of 6.1 metres. They can be grown as standalone vertical accents but their narrow width of 1.8 metres also makes them well- suited for privacy hedges and urban screening.

Green Wall Spire is now part of the prestigious line of First Editions, a brand offered by Bailey Nurseries in Minnesota to their customers in the U.S. One of those customers is Martha Stewart, the lifestyle icon and television personality. Last fall, Stewart added several Green Wall Spire flowering crabapples to the garden maze she is designing at her farm in Bedford, New York.

The use of recently developed columnar crabapples have opened up a whole new market for flowering crabapples, says Wilbert Ronald. “They are replacing the overused disease-susceptible columnar aspens which have dominated the market for the past 40 years (and) are becoming a success story in prairie tree use.”

Still, despite Spring Snow’s problems with disease, especially in soggy soils, it is still being used in the landscape because it is seedless, that is, it does not produce fruit. So,there is no messy fruit to clean up in the fall, says Durand, whose breeding work for the past several years has been focused on reducing the size of fruit in flowering crabapples.

Flowering crabapples have long been an important source of food for wildlife but there are areas in the landscape where fruit is not desired, says Durand — next to swimming pools, ponds and decks, for example.

Courageous Rosybloom Crabapple, developed by Durand at Prairie Shade Nursery in Portage la Prairie, is a seedless cultivar that rarely produces fruit. “It’s very low maintenance,” says Durand. “Any tiny little fruit that it does produce just kind of dries up.”

Courageous grows to a height of 6.1 metres but has a broader form at 4.6 metres wide. The new leaves exhibit a maroon appearance before turning green-bronze in summer. Fall colour is yellow-orange. Courageous has excellent resistance to fire blight and apple scab and is hardy to Zone 2.

Courageous Rosybloom Crabapple was selected and named for Lawrence Aubin, who took over the operation of Aubin Nurseries in Carmen in 1959.

“Courageous was named in honour of my grandfather as a tribute to his courageous battle with cancer as well as his perseverance in building a successful nursery business in Manitoba’s challenging Zone 3 climate,” says grandson Garth Aubin, manager of inventory and logistics at Aubin Nursery.

Today, Courageous Rosybloom Crabapple is part of Bailey Nurseries’ First Editions collection.

New flowering crabapples include Velocity and Lightsaber. Velocity Flowering Crabapple was selected at Sunstar Nurseries in Edmonton. It has an upright, oval shape with a mature height of 8 metres and grows to 4 metres wide. Hardy to Zone 2, it does not produce fruit and is disease-resistant.

Lightsaber Flowering Crabapple, developed at Bylands Nurseries in Kelowna, is a columnar flowering crabapple with a very narrow form (2 metres). It also has high disease resistance and is a strong selection for screens and tight spaces. However, it has fruit drop late in fall.

Another variety new to the market with a very narrow form (1.8m) is Slim Pickings Columnar Crabapple. Developed by Durand for Bylands Nurseries, Slim Pickings features dark green foliage in summer with purple fall colour. An open-pollinated seedling of Starlite Flowering Crabapple, Slim Pickings has limited flower display and there is still some fruit.

Falk Nurseries in New Bothwell is carrying Velocity and Lightsaber flowering crabapples this year. Morden Nurseries is carrying Slim Pickings and Velocity and expects to offer Lightsaber in the future.

So, while the goal for the last 20 years has been to produce flowering crabapples that take up less space and are more disease resistant, there is still the matter of the fruit. Overwintering birds depend on fruit for sustenance. A cultivar such as Starlite Flowering Crabapple, developed by Jeffries Nurseries, has excellent resistance to foliar diseases, including apple scab and retains its small fruit into winter. Starlite has glossy green foliage and a broad, upright form (7.6m tall and 4.6m wide).

Flower, form, foliage, fruit and fall colour are five reasons to use flowering crabapples in the landscape, says Wilbert Ronald.

Interesting forms are on the horizon. New for 2027 are two flowering crabapples, Velvet Cascade and Jade Cascade.

Selected by Durand for Bylands Nurseries, both have a narrow width (1.8m) and a unique weeping shape. They will be an excellent choice for tight spaces or privacy screening.

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