How to nurse gardens through a hellish summer

What happens to great gardens when the drought hits hard?

Highfields at Little Hartley, NSW. Picture: Claire Takacs

What happens to great gardens when the drought hits hard? In January the outlook was grim for garden designer and plantsman David Kennedy, who, with his partner Andrew Dunshea, was struggling to keep two gardens alive. It was so hot and so dry that Kennedy was worried for their future. “We’ve invested so much, we just had to keep going,” he says.

Over the past 20 years, Kennedy has created Clover Hill – a 1000sqm garden packed with rare and unusual plants – at Katoomba, in the Blue Mountains west of Sydney. It holds significant collections of cool-climate treasures such as epimediums, trilliums, hostas and bulbs, underpinning Kennedy’s rare plant mail order nursery.

David Kennedy and Andrew Dunshea. Picture: Claire Takacs

By 2014, he and Dunshea had run out of room and craved a sunny site where they could grow different plants and build a house. So they bought a 3ha cow paddock with stunning views on the other side of the mountains at Little Hartley. That property, Highfields, experiences hot, dry summers and winters down to -8ºC, with plenty of frosts. Into the property’s natural basin they dug a chain of ponds leading to a dam, and terraced the gardens to direct water run-off to them. “Things grow like a rocket here when they have water,” says Kennedy.

Highfields at Little Hartley, NSW. Picture: Claire Takacs

The pair put in windbreaks to protect against the fierce westerlies and built hundreds of metres of rock walling; they now have nearly 2ha of garden at Highfields. Kennedy’s design includes a large “dry garden” that is not watered; a prairie garden featuring thousands of perennials, grasses and self-seeding annuals; the birch grove and woodland garden; and the Asiatic garden with flowering cherries, waterfalls, maples, peonies and conifers. In the circular entry court, white roses, lavender, catmint and topiarised bay trees create a romantic space, while the “Barry Manilow” garden is a long border of intense colours.

Rock walling at Highfields. Picture: Claire Takacs

This summer it all became a struggle. “I’ve never seen such devastation, even in the Millennium drought,” says Kennedy. “I dread to think how much stuff I lost at Katoomba. It was a nightmare – there was no time to do anything but water.” Before rains arrived in February, he’d been buying a tanker of water every five days for Highfields and carting water in his car to keep precious trees alive. He let whole groups of plants die. “To the geums, asters and eupatoriums I had to say, ‘Sorry, if you can’t make it, I don’t want to grow you any more’. Even the lavenders struggled but the ornamental pears, smoke bush, Phlomis and cotton lavenders didn’t miss a beat.”

With the dam and tanks now happily full, they’re back to finishing the house and studio, which will later take B&B guests. Highfields first opened to visitors in spring and Kennedy is confident the planned open days for this autumn can proceed. “Although we’ve just had one extreme to the other, the last two summers have been so hot, I’ve been thinking, ‘Is this going to be the new norm?’” he says. “We’re just going to have to adapt.”

See cloverhillrareplants.com.au for open days at Highfields.

Q&A

After the drought and bushfires, I noticed the young branches on my liquidambar tree have a spiny growth along their length, like a dinosaur’s back. What should I do? Kirsty Kaye, Bega, NSW

Liquidambars have thin flaps of corky bark that attach edge-on to the smaller branches, giving them a reptilian appearance. The bark later becomes deeply furrowed on the trunk and large branches. This is a natural feature of liquidambars that often goes unnoticed, but after the recent devastation many defoliated trees are being closely inspected for signs of recovery.

Why does my cumquat tree have yellow-green leaves? I’ve fed it some citrus fertiliser, and I give it bath water. The fruit tend to be small and not juicy. Theresa F, Maitland, NSW

Citrus are described (rather cruelly) as “gross feeders”, meaning they love food and regular water. Give them some fertiliser every month – they thrive on chook poo-based products such as Dynamic Lifter For Fruit & Citrus or Neutrog’s Gyganic, which also contain the necessary trace elements for citrus. You can apply a soluble trace element mix as a foliar spray. Bath soaps tend to be alkaline, so continual use could make your soil alkaline, which would affect uptake of nutrients. Check the pH is between 6 and 7.

My healthy olive tree has never produced olives in 15 years. What am I doing wrong? Ros Mayes, Eumundi, Qld

It’s not you. Olives are Mediterranean plants that just don’t fruit well in humid areas. They need cross-pollination from another variety for good crops, so you could get it a friend. Otherwise, just enjoy its shape and silvery foliage.

Send your questions to: [e-mail] or Helen Young, PO Box 3098, Willoughby North, NSW 2068. The best question for March wins Fiskars’ PowerGear X loppers, worth $100. February’s winner is Julie Riley of Bundarra, NSW for her question about drought-affected trees.