‘What is the best use for corks in the garden?’ One of the more unusual enquiries put to the RHS Gardening Advice team this year. The only sensible idea was to use them for cane toppers to keep your eyes safe when bending down in a border. Most of the other 115,000 questions to our team of 21 advisors were more straightforward.
Biodiversity
Wildlife gardening enquiries were up by 28% this year. Letting the grass grow long and allowing wildflowers to bloom in your lawn, is now a far more popular question than how to get great lawn stripes. There’s an increased interest in supporting birds, pollinating insects, invertebrates and other wildlife, by growing plants that offer food from pollen, nectar and berries, and provide shelter.
Gardeners are increasingly more environmentally aware in their day-to-day gardening. They are looking for natural ways to deal with ‘problems’, which are now seen as ‘nice-to-haves’. For example, common cow parsley is now a desirable border plant and there is an increased awareness that dandelions are key for providing food for bees in early spring.
Even small changes can make a big difference; not reaching for sprays; planting pollinator-friendly garden plants; including at least 20% native plants, and reducing tidiness so plant debris supports the food chain. Having a wildlife-friendly pond can support a large range of wildlife. Not all gardeners have space for a pond but even a small bird bath will help feathered friends and insects.
Winter cold damage
We have seen 12 times as many enquiries about frost damage in 2023, following two spells of cold weather.
Much of the damage was caused by one of the most significant colds spells for over a decade. After above average, warm autumn weather, the sudden prolonged frost of December 2022, badly damaged many plants that were still in growth. Our gardens were no exception, with less than -10˚C recorded at RHS Garden Wisley in Surrey and RHS Harlow Carr in Yorkshire. The entire RHS Plant Trial of 126 shrubby Veronica (hebe) at Wisley was lost, except Veronica pimeleoides ‘Quicksilver’, Veronica ochracea ‘James Stirling’ and Veronica odora ‘New Zealand Gold’.
Plants that suffered the most were Pittosporum, Cordyline and Phormium. Surprisingly the usually tough and hardy Clematis montana frequently failed to regrow in spring.
To minimise winter damage, consider protecting borderline hardy plants or opt for hardier alternatives. Check winter hardiness ratings of plants using RHS Find a Plant online, particularly if you garden in a cold area.
The extremes of temperature are consistent with the predictions of climate change, so choosing plants that are resilient to cold temperatures, water fluctuations, and wind are now key factors when buying.
Difficult summer
Weather-related plant damage questions nearly doubled as summer began, reflecting the changeable conditions. The hottest June on UK record came while plants were still producing lush growth. This stressed newly planted and well-established plants, seeking moisture to support their new shoots and blooms.
July followed with wet and cooler conditions, encouraging fungal diseases: scab, blight, leaf spot, powdery mildew and rusts in particular. Most do not kill garden plants but can weaken them, reduce flowering and look unsightly, showing the importance of ‘right plant; right place’. Think about hardiness, soil type, position and aspect, so that plants in our gardens are more likely to cope with extremes of weather. Good aftercare, which helps plants to establish, gives them a better chance of being more resilient.
Box tree moth
One of the most frequently asked questions is how to deal with box caterpillar, which has resulted in many UK gardeners replacing their tatty, damaged hedges with more suitable replacements.
There is no exact substitute for box (buxus), but the box alternatives RHS Plant Trial at Wisley is helping gardeners choose alternatives. This is despite the 2022/2023 winter damage to Pittosporum, which forced us to reconsider the front runners. Based on extensive research from amateurs and professionals, we produced a list of alternatives. Yew has continued to prove it can be tough, reliable and well able to withstand clipping to 50cm tall.
Our entomology team also received more enquiries about aphids outdoors and thrips on houseplants. Aphid numbers remained high through the summer, with a marked rise of enquiries related to rosy apple aphid damage that causes leaf-curling in spring and distortion of the fruit. This trend could be a knock on effect of the extreme hot and dry weather of 2022, with predator numbers being slower to recover. This makes it more important than ever to encourage natural predators such as ladybirds and ground beetles, by creating wildlife habitats in the garden.
Houseplants
It is not necessary to have a garden to grow houseplants. Members asked how to look after their plants and what to grow to fill every corner of their homes. Leafy, tropical-looking plants and orchids are very popular, bringing a jungle vibe to our living quarters.
Many opt for cacti and succulents as a lower maintenance option that suits busy lifestyles. To bring a touch of the Mediterranean to our homes, citrus growing is popular, with enquiries increasing by 22% in 2023. Although citrus fruits are generally better suited to conservatory growing, they enjoy a summer holiday outdoors in the garden.
Watering is a key issue when houseplants look sickly. Most hate sitting in a puddle, held inside those gorgeous decorative outer pots without drainage. Sporadic watering, allowing plants to dry out too much and then overcompensating by soaking the compost, is best avoided. In fact, keeping the compost just moist is our top tip for success in 2023.
If you love houseplants and you love an RHS show, put the date in your diary of the very first RHS Urban Show, being held in Manchester (18–21 April). Tickets are on sale now.
Grow Your Own
Tomatoes continue to hold the top spot of ‘grow your own’ questions, followed by potatoes, cucumbers, courgettes, chillies and runner beans. Home-grown ripe tomatoes picked straight from the vine taste so much better than shop offerings. They are easy to grow from seed, so you can try something different every year. They come in many shapes, sizes and colours. The RHS holds trials, and awards an Award of Garden Merit for the plants, and fruit and vegetables that have proven to be the most reliable for a number of reasons.
Container grown plants can fit in the smallest of gardens and balconies – even in hanging baskets. The dull, wet weather of summer 2023 made tomato growing more challenging. We saw an increase in enquiries about tomato blight disease (encouraged by the warm, damp conditions), which sometimes ruined the tomato crop. Outdoor-grown tomatoes are more vulnerable to the infection. If you can’t grow tomatoes under cover, it is a good idea to grow blight-resistant cultivars.<
Fruit
Apples, plums, figs, pears and raspberries were the most asked about fruit, with apples wearing the crown. There were more than 2,100 apple enquiries, up by 10% from 2022. Questions ranged from choosing cultivars, growing and pruning, to potential problems. We recommend growing RHS AGM cultivars for success – these are tested to grow well in average garden conditions by RHS experts.
Gardeners often need help with pruning their fruit trees. In particular, they asked about pruning old or overgrown apple and pear trees, about pruning space-saving forms such as cordons and espaliers, and how to deal with watershoots (vigorous regrowth that appears after pruning that was too hard). Many gardeners also find pruning fig trees tricky. Our revised pruning pages now include diagrams that should give gardeners more confidence.
The RHS members’ postal fruit identification service remains popular. So far, no other apple knocked ‘Bramley’s Seedling’ from the top spot. The top five include ‘Lord Lambourne’, ‘Newton Wonder’, ‘James Grieve’ and ‘Laxton’s Superb’.