Owners wishing to open their gardens under the scheme are required to meet a certain, if nebulous, standard: their efforts must be able to sustain the interest of "a keen gardener" for about 45 minutes who may have travelled 15 or 20 miles to get there. The informal assessment process - the scheme stresses that this is not "a horticultural judgement" - is carried out by the county organisers (volunteers whose own gardens have once had to undergo consideration for the scheme) and usually takes place over the summer. As one organiser put it, they "get to know your garden" for about an hour.
A straw poll of county organisers seemed to suggest that most gardens are accepted on to the scheme, though they emphasised that this was a testament to the excellent horticultural standard of gardens put forward. The organisers I spoke to squirmed at the prospect of turning a garden down: "People are offering something very dear to them for nothing". If shrubberies look a bit slipshod, organisers, like Joanna Kerr in Gwent, are the epitome of tact: "We make suggestions and encourage them to try again in a year or two."
As for the gardens themselves, almost anything goes. As Penny Snell says: "If the garden is excellent in its own right, even if it's not to my taste, we'll take it on." You needn't litter your beds with rare and exotic flora, according to Ray Brown, Derbyshire organiser. "Your plants can be pretty ordinary - it's the overall composition that matters."
Publication deadlines for details of the gardens to be entered in the "Little Yellow Book" mean final considerations are made by late September. If successful, garden owners are contacted early in the spring concerning the arrangements for opening. Owners set the entrance charges and may open as many times as they wish. The scheme gives considerable support and provides printed signs and security advice.
There is little doubt that an entry in the Yellow Book does no harm to the value of your property, but the organisers demur at such suggestions. "Some owners think it has as certain cachet, but that really isn't in the spirit of the National Gardens Scheme," insists Michael Stone, assistant organiser in Devon. Nicky Pickett of the Royal Horticultural Society agrees, adding: "Not only is it a great charity, but people get to see what can be achieved with very limited resources in some cases."
To celebrate the National Garden Scheme's 70th anniversary, the RHS gardens at Wisley are being opened on the evenings of 18 June, 6.30-9pm and 14 August, 6.30-9pm. Admission is pounds 3, in aid of the scheme. For more details 01483 211 535.
The National Garden Scheme Yellow Book, `Gardens of England and Wales Open for Charity 1997', pounds 3.50, is available from most good bookshops. Or write to the National Gardens Scheme, Hatchlands Park, East Clandon, Guildford, Surrey GU4 7RT, with a cheque for pounds 4.25.