Oak Leaf Gardening Monthly Cuttings
Newsletter 24 - May 2013
What to do now

Ornamental plants

  • Finish off sowing hardy annuals early this month. Continue to sow biennials such as honesty, foxgloves, stocks and wallflowers.
  • Keep on top of the pricking out, pinching out and potting on of seedlings.
  • Harden off and plant bedding and tender plants (leave towards the end of the month in cooler climates) including containers and hanging baskets.
  • Plant out summer bulbs including acidanthera, cannas, eucomis, dahlias, gladioli, galtonia, calla lilies, arisaemas, liatris, oxalis and tuberous begonias.
  • Clear spring bedding to make way for summer blooms.
  • Continue to deadhead spring flowering bulbs and camellias. Cut down the foliage from spring flowered bulbs six weeks after the flowers have died down.
  • Put supports in place for tall perennials.
  • Train climbers such as clematis while the shoots are still young and pliable.
  • Prune spring flowering shrubs such as Ribes sanguineum, Clematis armandii, pyracantha, chaenomeles and forsythia after flowering.
  • Clip beech, hornbeam, box, thuja, privet, Lonicera nitida and leyland cypress hedges late this month, making sure no birds are nesting in them.
Fruit and veg
  • Sow tomatoes under glass and, later in the month, sweet peppers, chillies, aubergines, melons and cucumbers.
  • Outdoors you can sow swedes, beetroot, maincrop carrots, Brussels sprouts, autumn cabbages, autumn/winter cauliflowers, calabrese broccoli, peas, Swiss chard, radishes, lettuce, mangetout, French beans, runner beans, turnips, endives, fennel, kale, kohl rabi, sweetcorn, courgettes, squashes (including butternut squash), pumpkins and spring onions.
  • Continue to earth up potatoes regularly.
  • Keep soft fruit bushes well watered.
  • Put straw or other liners under strawberries to protect the fruit from grey mould.
  • Cover or put up a barrier (of fine mesh/plastic film) 45cm high around carrots to protect them from carrot fly. Cover cabbages with a similar material to keep off the cabbage white butterflies.
  • Start harvesting your asparagus, lettuce, radishes, rocket, baby potatoes and overwintered onions.
General tasks
  • Mow your lawn weekly to around 2.5cm, longer if a drought is forecast. This is your last chance to re-seed any dead patches before the summer.
  • Use a 'weed and feed' product on your lawn, if you didn't do it last month.
  • Keep on top of the weeding.
  • Apply summer shading to your greenhouse towards the end of the month to protect plants from scorching.
  • Ventilate greenhouses during warm days, but remember to close them up in the evening.
  • Scoop duckweed and blanketweed out of ponds and re-stock with aquatic plants.
Tulipa 'Esperanto'Plant of the month

Tulipa 'Esperanto' is a late flowering tulip which appears in early May. Each tepal has a central line of dark green, which fades to a scarlet red. The green leaves are variegated with a pretty, silvery-white edging. Find out more...

Problem of the monthPollen beetle

Pollen beetles are small (2 to 3mm) black or green/bronze beetles which can be found, usually in large numbers, feeding on flowers from May throughout the summer. They damage flowers and can completely destroy them. Shake the beetles off or put infested flowers into the shade for a few hours to get rid of them. Chemical controls are not recommended. Find out more...

In the news

2 year restrictions on neonicotinoid insecticides

The European Commission will introduce EU-wide restrictions on the use of neonicotinoid insecticides from July of this year at the latest. The controls will prevent the use of these chemicals on crops which are attractive to bees and other pollinators.

Raymond Blanc launches garden design competition

Chef Raymond Blanc has announced a competition to design a new heritage kitchen garden for his Michelin starred restaurant Le Manoir aux Quat’Saisons. Two winners will be selected, one professional garden designer and one amateur enthusiast, who will work together on an integrated programme of gardening, horticulture and design.

Possible sweet chestnut import ban

The Horticultural Trades Association (HTA) have called for a ban on the import of sweet chestnut trees in order to arrest the spread of the fungus Cryphonectria parasitica. This disease has already affected plants at two UK sites and 180 trees have been destroyed as a result. While the disease is not as aggressive as ash dieback disease, the HTA believe that sweet chestnuts may become more important to the UK's woodlands as replacement for ashes.

Children want to be greener-fingered

A recent Homebase survey of 1,000 children has discovered that 62% of them would like to learn more about gardening at school. Their interest is keenest at junior school age - 41% of seven year olds stated that the garden was their favourite part of the home.


Chelsea celebrates 100 years of shows

Chelsea 2012This month's RHS Chelsea Flower Show will be looking back at a centenary of shows and forwards towards the sustainable gardens of the future.

Many of the displays will be themed to mark this milestone, including the M&G garden which will reflect garden design past and present, a public vote to find the Plant of the Century, an exhibition of photographs from the 100 years of shows and Sitting Spiritually will be selling 100 bespoke, commemorative benches - a snip at just £4,499 each!

Here are some of the highlights to watch out for, whether you're visiting the show in person or catching up with it on TV:

  • This year's Arthritis Research UK garden is designed by Chris Beardshaw, who was diagnosed with the condition at the age of 19. The garden will show a journey of someone with arthritis. The design is split into three areas which take the visitor from the early confusion of diagnosis to the successful management of the disease.
  • In the Floral Pavilion many displays will juxtapose modern plants with those found at the 2013 show. In fact three exhibitors will find this particularly easy as they have been at every show since 1913 - McBean's Orchids, Blackmore & Langdon and Kelways.
  • The Delancey's East Village Garden, designed by Michael Balston and Marie-Louise Agius, will demonstrate the sustainable redevelopment of an urban area by reflecting the landscaping and planting used at the London 2012 Olympic Park.
  • Jo Thompson's garden, designed for the Food and Environment Research Agency (FERA), is a sunken garden which aims to publicise the threat to our native plants from pests, diseases and invasive species. The controversial design will include an avenue of dead trees and hopes to encourage people to 'stop the spread'.
  • Christopher Bradley-Hole will be designing this year's Daily Telegraph garden which will combine a Japanese style with native UK planting.
  • Prince Harry has had a hand in garden design this year, supporting Jinny Blom in the planning of a garden sponsored by B&Q and the Prince's charity, Sentebale. Sentebale, which means 'forget me not' in Sesotho, works with vulnerable children in Lesotho, and the Chelsea garden will evoke the landscape of this impoverished African country.
  • The Trailfinders/Flemings Australia Garden is one of several designs at this year's show which focus on sustainable gardening. Philip Johnson's Aussie themed design is powered by the sun and all the water is ecologically channelled from surrounding areas. The materials used on the site are either locally sourced or reclaimed.
  • After last year's successful debut the Artisan Retreats will return to Chelsea with the summerhouses designed by the likes of Wayne Hemmingway and Cath Kidston.
  • The Stoke-on-Trent Garden Partnership garden celebrates the city's journey from an industrial giant to a vibrant modern city. The design will feature the skeleton of a bottle kiln and thousands of ceramic flowers made by local school children.

The RHS will also announce the winner of their public vote for the 'plant of the century'. The shortlist for this award are:

  • 1913-22 Saxifraga 'Tumbling Waters', bred by Bertram Symons-Jeune.
  • 1923-32 Pieris formosa var. forrestii, introduced by Victorian plant hunter George Forrest.
  • 1933-42 Lupinus Russell group, bred by George Russell.
  • 1943-52 Rhododendron yakushimanum, collected by Takenoshin Nakai.
  • 1953-62 Rosa 'Iceberg', bred by Reimer Kordes.
  • 1963-72 Cornus 'Eddie's White Wonder', bred by Henry M Eddie.
  • 1973-82 Erysimum 'Bowles's Mauve', breeder unknown.
  • 1983-92 Heuchera villosa 'Palace Purple', raised by Brian Halliwell.
  • 1993-2002 Geranium wallichianum 'Rozanne', bred by Donald Waterer.
  • 2003-12 Streptocarpus 'Harlequin Blue', raised by Lynne Dibley.

You can vote for your favourite at the RHS website.

Image: The Arthritis Research UK Garden, designed by Thomas Hoblyn, at the 2012 show. More about the 2012 show.


What's on this month

Your garden might be demanding your attention, but why not take a break from all that hard work to get some inspiration from someone else's efforts:

  • 4th to 6th May - Hertfordshire Garden Show, Knebworth House, Knebworth, Hertfordshire.
  • 4th to 6th May - Southend Spring Garden Show, Garon Park, Southend, Essex.
  • 4th to 6th May - Milton Keynes Garden and Home Show, National Bowl, Milton Keynes, Buckinghamshire.
  • 9th to 12th May - Malvern Spring Gardening Show, Malvern Showground, Malvern, Worcestershire.
  • 10th to 12th May - The Norfolk Spring Garden Show, Norfolk Showground, Norwich, Norfolk.
  • 11th & 12th May - Spring Vegetable Weekend, Barnsdale Gardens, Oakham, Rutland.
  • 15th May - London Head Gardeners lecture, Fulham Palace, Fulham, London.
  • 17th to 19th May - The Essex Garden Show, The Brentwood Centre, Brentwood, Essex.
  • 19th May - Sow and Grow, Ham House and Garden, Richmond-Upon-Thames, London.
  • 21st to 25th May - RHS Chelsea Flower Show, Royal Hospital, Chelsea, London.
  • 25th & 26th May - Edible Gardening; Seasonal Advice, Royal Botanic Garden Edinburgh, Edinburgh.
  • 25th to 27th May - Lea Valley Cactus and Succulent Show, Capel Manor Gardens, Enfield, Middlesex.
  • 26th & 27th May - Tavistock Garden Festival, Tavistock Town Hall, Tavistock, Devon.
  • 31st May to 2nd June - Gardening Scotland, The Royal Highland Centre, Ingliston, Edinburgh.
  • 31st May to 2nd June - Holker Garden Festival, Holker Hall and Gardens, Cark-In-Cartmel, Cumbria.