Stand by your beds...busy Lizzies return to gardens
BRITAIN’S favourite bedding plant, nearly wiped out by deadly disease, is set to bloom again this summer, thanks to dedicated horticulturalists.
Seven years ago busy Lizzies – scientific name Impatiens walleriana – were pulled from sale by garden centres and plant suppliers when fungal disease struck.
Impatiens downy mildew, which developed a resistance to the fungicide used to treat it, threatened the whole population.
But the flowering plant’s future is brighter after experts created a highly resistant variety through genome sequencing and hybridisation. The result, Beacon Impatiens is now being supplied by British plant supplier Ball Colegrave.
Seeds are also expected to go on sale soon at garden centres and through mail order companies.
Busy Lizzies began suffering from outbreaks of the downy mildew – Plasmopara obducens – in 2003.
The airborne disease appears as a white powder on the underside of leaves, causing them to yellow and fall off, leaving just a bare stem.
It is thought to have been brought into the UK from imported cuttings.
There was another outbreak in 2007-8 and another in 2011.
Despite the busy Lizzie market being worth more than £40million, many retailers decided to stop selling the plants in 2012 to give the plant the chance to recover.
Even Daily Express gardening columnist Alan Titchmarsh urged gardeners to buy geraniums, begonias, petunias and marigolds instead.
Many growers and retailers have been reluctant to stock the plant since, while UK gardeners have mourned the loss of their favourite.
But an intense breeding programme was begun in
2008 to develop a diseaseresistant variety by Ball Colgrave’s sister company PanAmerican Seeds and research company KeyGene.
Busy Lizzies are perfect in pots Ruud Brinkkemper, a breeder at PanAmerican, said: “In Impatiens the downy mildew has been really devastating – no other disease has had such an impact on a crop in our industry.
“We tried several different approaches, some didn’t work but we found a strong source of resistance. “We keep crossing that resistance in and select the best plants. It takes a lot of work and there are a lot of waste plants that are not good enough to get the right one.
“We used technology, genome sequencing, to help us in the breeding process but we didn’t use technology to make the resistance, it’s not genetically-modified.” Mr Brinkkemper said in both indoor and outdoor trials, horticulturalists sprayed the disease on the Beacon busy Lizzies to test them. Describing the results, he said: “You can see the plant is resisting it – you might see a yellow leaf but the plant excises the leaf to protect itself. “In the past Impatiens had 30 different colours or more, with Beacon we have six so far but we hope to develop a few more. “The market has changed but this resistance means Impatiens can come back.
“It’s a product that gardeners know and like and there is not really another flower that has replaced them.
“We have high expectations for this – people still want it.”