Glengall Wharf Gardens is a haven of nature in a very urban part of South London (the Old Kent Road is only five minutes walk away). It depends entirely on volunteers who have done great things with little or no money. It was indeed a wharf on a long defunct and filled in canal. What remained was an area of concrete and cobbles which is now abundantly ecological.

 The hard standing inherited by the Glengall gardeners meant that they decided to build up rather than dig down. A large area is given over to raised beds and an equally large area to a developing forest garden based on Permaculture principles.

 The forest garden grows on a number of Hugel mounds- basically a giant raised bed where soil has been layered on top of decaying wood. The idea derives from Sepp Holzer's concepts of 'Hugelkultur' (hill culture), a big topic in its own right. At Glengall the mounds have been periodically mulched with wood chip, horse manure and compost.
 It's become a living soil rather different from the heavy clay based soil we have in much of London (though there are other soil types in London too). The Hugel mounds are very free draining and the soil is light, not rich but still fertile.
 [Correction Since writing these lines I have learned that not all the raised areas are Hugels; some are soil and mulch on top of rubble that had accumulated on the site prior to becoming a garden.] 
 The concept of indicator plants is a useful way to get a sense of soil type i.e. plants that suit particular conditions will thrive whereas others will not. It's noticeable that Mediterranean plants self-seed at Glengall very readily -Borage, Calendula, Wild Rocket for example- finding conditions on the mounds that correspond to their natural habitat.

 Numerous trees, shrubs and large perennials have been planted as part of the ongoing design process and many of these have flourished along with the aforementioned self-seeders and other weeds/wildflowers that like the conditions. Some "weeds" are welcome; no harm in having a patch of Stinging Nettles for example. 

 None the less the forest garden needs some attention as there are signs that 'succession' is starting to take hold. Where plants are concerned succession refers to the process whereby bare ground becomes grassy and weedy. The finer weeds and grasses are supplanted by the coarser ones which gives way to scrub which becomes woodland. Nature abhors a vacuum and will always seek to fill it.
 Now there's something to be said for letting nature run wild but it won't result in a food forest in the permacultural sense. Permaculture derives from the concept of a permanent agriculture using natural processes so seeks to address this by creating herbaceous and ground cover layers. These are productive in their own right and spread under the shrubs and trees preventing the ranker weeds from taking hold.

 NB Martin Crawford's forest garden in Devon is an exceptional example of a mature forest garden, 25 years in the making. See entry on 27th. February concerning my recent visit with examples of the seven layered approach.

 Rhubarb, rhubarb. Lifted a number of crowns from around the allotment to make a dedicated rhubarb patch. I love rhubarb though tart, astringent flavours don't seem to be popular these days.  
 Also put up the framework for runner beans. I used canes cut from the bamboo in my father's garden round the corner. Initially I was going to use some I bought in a shop. They looked pleasingly natural among the aisles of plastic but when I got them to the allotment I noticed they had a tiny label saying "Made in China".
 Now I know just about everything is manufactured in the East but it seems absurd that a bamboo cane has to travel around the globe to make a bean frame! I'll make use of them in due course but I decided to keep it local for the runners.

 Some flowers in the garden today: Garlic Mustard and Green Alkanet.

Siberian Bugloss and Hidcote comfrey.

Trout Lilly.

Yellow Archangel.

Oriental Borage

Greater Periwinkle.

White Deadnettle.

Herb Robert.

White Comfrey.

Red Campion.

NB I'll add the Latin names when I have more time!

 When I visited Butcher's Wood in Sussex last week the Wood Anemones were flowering in their thousands (entry dated 4th. April). Among them the first Bluebells (Hyacinthoides non-scripta) were coming into flower.
 As mentioned Anemone nemorosa is a species found in ancient woodlands and often shares that habitat with our native Bluebell. In the weeks ahead in locales like Butcher's Wood the drifts of white will give way to a haze of blue.

 A hedge of prickly Blackthorn (Prunus spinosa) runs along one side of the allotments. Blackthorn was a traditional choice -along with Hawthorne- for stock proof hedges and is still widely used as a hedging plant.

 Actually at first glance I took this to be a Hawthorn but I think I'm right in saying that P. spinosa has yellow tipped stamen (as seen above) rather than pink and flowers before it comes into leaf rather than after which differentiates it from Crataegus monogyna.

Honey bees were being busy bees on the flowers.

Note the bulging pollen sac on the hind leg.

NB Blackthorn is also known as Sloe so assuming my ID is correct these flowers should produce a crop of Sloes in the autumn in which case a bottle of Sloe Gin might be in order.

 Well, it's not quite the ancient woodland of my previous entry but I like it when suburbia gets a bit wild around the margins. I was out and about in affluent Dulwich earlier in the week and on the fringes of a politely manicured front garden I noticed this attractive tableau.
 The White Comfrey (Symphytum orientale) probably self-seeded and is merging with the plum-purple flowers of a Greater Periwinkle (Vinca major). Noted for being vigorous ground cover its trailing stems touch the ground, root and throw out more stems. The Periwinkle is growing through the holly-like leaves and yellow flowers of Oregon Grape (Mahonia aquifolium), which is a shrubby, suckering spreader.

 Wood Anemones (Anemone nemorosa) are a good example of how "wild" flowers can have a symbiotic relationship to human activity- in a good way.

 As its common name suggests A. nemorosa does indeed flourish in woods (and is an indicator that the wood is ancient). But it likes light too in the spring time so a coppiced wood is ideal.  
 These photos were taken at Butchers Wood near Hassocks in Sussex, an ancient wood of oak and hazel which is maintained by conservation volunteers. Coppicing was once widespread as a way to gather wood for various practical purposes whilst perpetuating the life of trees almost indefinitely. 

 Deep shade and an understorey of bramble and scrub is too much for the dainty Wood Anemone to compete with. This is a species that spreads very slowly by means of twig like rhizomes (possibly as little as six feet per century). Light filtering through a coppice onto the leaf litter of a woodland floor suits it down to the ground so to speak.

 Mostly the petals are of the purest white but some have an exquisite flush of pink.