Within the 1.5-acre (0.6-hectare) walled garden lies the National Collection of Historic Roses—an annual spectacle of blooms that captivate the senses with colour and fragrance.
Unlike modern hybrids that flower repeatedly, the roses at Mottisfont typically bloom just once a year. But this season, they've reached their peak nearly two weeks ahead of schedule.
Harvey points to the warmer-than-average spring as the cause: "An exceptionally warm and dry March and April has really pushed the plants. Because of climate change, the rose season keeps arriving earlier."
To help the roses adapt, the gardening team has ramped up care practices. A key method is mulching—laying down thick organic material across the soil surface.
"Each year, we spread around 120 tonnes of mulch," Harvey explains. "A 2-inch (5cm) layer creates a protective barrier that shields the soil from intense sun, adds nutrients, and helps retain water."
The team is also investing in more efficient irrigation and rainwater collection systems. Some roses struggling with sun stress—evidenced by scorched, brown leaves—are being relocated to shadier parts of the garden. It's about, as Harvey puts it, "putting the right rose in the right place."
Climate shifts are also impacting the winter season. Warmer, wetter winters mean pests aren't being killed off by cold snaps, and roses experience shorter dormancy periods, disrupting their growth cycles.
The historic garden was first created in the 1970s by horticulturist Graham Stuart Thomas, who gathered rare rose varieties from around the globe. Today, it draws roughly 84,000 visitors each year during the flowering season.
"This is an irreplaceable collection," Harvey says. "Some of the UK's and even the world's rarest roses are found only in this garden. If they disappear, we can't get them back."
To safeguard these precious plants, the Mottisfont team is also looking beyond the UK. In September 2024, they travelled to Ethiopia as part of the International National Trusts Organisation's "Withstanding Change" project—an initiative focused on climate resilience.
"It's a conversation between us and gardeners in Ethiopia, sharing stories about the challenges we're all facing," says Harvey.
Despite the climate pressures, the garden is currently bursting with life. Mottisfont is encouraging visitors to come in the coming weeks—when the roses are at their finest—with extended evening hours and newly trained rose volunteers on site to guide guests.
Harvey beams as he looks out at the display: "It's like a mini Chelsea Flower Show here."
"The thing about historic roses is that each one has personality. They've all got something to say. It's beautiful."