Following on from my successful visit to Graythwaite Hall gardens last week, I fetched up at Holker Hall on Tuesday, to look at the Styrax collection.

Holker Hall Gardens contains the National Collection of Styracaceae - a genus which contains a number of unusual flowering shrubs, including Halesia, Styrax, Pterostyrax and Sinojackia.

I was shown round by Yvonne Cannon, head gardener at Holker since January this year and already having an impact on the garden. Beds and borders were looking immaculate ahead of the Holker Festival, which runs from June 1-3 this year.

Appropriately enough, the North West group of the NCCPG (which administers the National Plant Collections Scheme) will have a plant stall at the Festival, in the Rare Plants Marquee, to raise money in support of NCCPG. The group will have some interesting and unusual plants for sale together with sound advice on how to grow them.

I came across a couple of interesting and unusual plants in the borders at Holker, which had me reaching for my plant encyclopaedia when I got home. I think the first was a white form of sweet rocket, Hesperia matrionalis var. albiflora, though if anyone can confirm or correct this tentative identification using my photograph, I'd be grateful.

The second plant I'm more confident about. It was a spreading shrub, or small tree, with very attractive, five-petalled, white flowers not unlike small roses. Where the petals had fallen, small fruits were forming, each with five long ears' (which turn out to be more correctly described as persistent calyces'). The leaves were large, dark green and leathery.

This was a medlar, Mespilus germanica, a native of South West Asia and South East Europe that has long been cultivated in the UK, though it's rarely seen nowadays outside collections. The fruits, which are hard and acidic, were eaten by the Greeks and Romans as a cure for a variety of ailments. They can be made into preserves, but can only be eaten raw when bletted or beginning to rot after being frosted. Medlar jelly and medlar cheese (like lemon curd) used to be popular, as was Medlar wine.

There are several cultivated varieties of Medlar, including Nottingham' (which is considered to have the best flavour) and Breda Giant', a large fruited variety from Holland.

With excellent autumn colour listed as one of its main attributes, in addition to the beautiful flowers and unusual fruits, this is a tree that deserves to be much more widely planted.

Jobs for the gardener this week...

Plant out summer bedding, put out hanging baskets and plant up pots and tubs as long as there are no frosts forecast. Wait another week if the nights are still chilly.

Clip box hedging.

Sow runner beans, sweet corn and courgettes in the vegetable plot.