The first part is the same for both Red and Yellow routes so posts have Red/Yellow marks. The routes are described in Clockwise direction.
From the entrance (Post 1) walk straight ahead. As you progress forward to the next post you will see on your left one of the interesting trees in this section the large spreading Ostrya carpinifolia, (Hop Hornbeam). Continue forward to Post 2 at the large upright Quercus robur fastigiata (Fastigiate Oak)
From Post 2 go left through the Pines to reach Post 3.
This brings you to the Glebe Lawn with the Westminster Border on the right. This border was planted with silver featured trees to commemorate the Silver Wedding of Sir Bernard and Lady Lovell. It contains Cornus ‘Eddies White Wonder’, Acer saccharinum with silvery backed leaves, Pyrus salicifolia and the snake bark maple Acer rufinerve. As you enter the lawn look to the left and next to the large Mahonia you will see a fine specimen of Cornus kousa. Walk across the lawn to Post 4 which marks Knights Avenue.
This avenue is so-called because the Lombardy poplars were planted to commemorate Sir Bernard’s knighthood in 1961. Turn Right along the path to the lake and seat (Post 5)
From here you can see Reith Avenue on your left at the far side of the lake This avenue was planted with red twigged limes to celebrate Sir Bernard’s Reith Lectures for the BBC. On this far side of the Lake is a Platanus orientalis (Oriental Plane – the Hippocratic tree where there is a notice explaining the history of the tree). From Post 5 you can view the Taxodium distichum(Swamp Cypress) on the island in the lake. Continue down Knight’s Avenue on the right hand side of the Lake to the end and straight on to (Post 6) Here there is a large Cornus macrophylla.
Leave the Yellow Route here and go left. Pass between Robinia pseudoacacia (Common Acacia) to your right and a row of mainly Acer species (Maples) to your left and continue to (Post 7). This is situated by a large Acer monspessulanum (Montpelier Maple) a species from Southern Europe to West Asia.
Continue ahead to (Post 8) and go slightly downhill past the Hebe Collection, which is maintained by the Hebe Society, and continue past the Acer macrophyllum (Oregon Maple) on the left and Euonymus phellomanus on the right to reach (Post 9) by a group of four Calocedrus decurrens (Incense Cedar).
Swing right across the slope past (Post 10) to a Juniperus recurva coxii (Drooping Juniper) on the right to arrive at (Post 11) by the Quercus libani (Lebanon Oak) on Golden Avenue.
Go left downhill, past several oaks on the left, to (Post 12) by the Viewpoint. As you go downhill you may notice that a ‘Winter Walk’ is being developed on the far left in front of a row of birches. This area contains a group of mainly Cornus (Dogwood) and Salix (Willow) which has been planted for winter interest.
From the Viewpoint go right along the edge of the site passing some Larix marschlinsii (Hybrid Larch) on the right to (Post 13) and continue past the Nature Reserve gate to (Post 14) at the edge of the area known as Wheat field South.
Bear diagonally uphill passing a group of Salix species (Willows) to reach (Post 15).
Continue on passing a group of Fagus sylvatica Dawyck (various forms of Dawyck Beech) on the left and a group of Malus species (Crab apples) to (Post 16) at The Great Avenue – planted in 1996 by local schoolchildren.
Go into this Avenue of native trees and follow it eastwards back in the direction of the entrance.
At (Post 17) the main collection of Pinus species (Pines) is in the field to your left (Barnfield North). The Arboretum holds a National Collection of this genus. Continue to (Post 18). Here in the field to your right (Barnfield South) is the main Fraxinus (Ash) collection. Again the Arboretum holds a National Collection of this genus. Also in this field is a large number of Quercus sp. (Oaks).
Continue up the avenue to (Post 19). In the fields on the left and right are most of the coniferous trees which are part of the Royal Botanic Gardens Edinburgh Endangered Conifer programme. The Arboretum is an outstation of this programme in which trees from wild collected seed are grown and monitored.
Go to the end of the Avenue and at (Post 20) bear right through the gap to (Post 21) which is near a Quercus macranthera (Oak) and Corylopsis sinensis calvescens, a lovely woodland species with drooping racemes of yellow flowers in Spring.
From here you will see the notice board and exit.
Leave the Red Route here and continue right (with Campanow and the view over the Dane Valley being further down on your left.) Walk across into an area known as Broom Field where Post 7 is found. This area contains a number of fairly tender species; Enkianthus is on the left and Magnolia kobus is to the right.
Continue on this pathway to Post 8. You will pass a number of interesting trees before you arrive at a line of conifers. Of particular note are a Cercis siliquastrum (Judas tree), whose bright pink flowers appear in Spring before its circular leaves, two Malus (Crab apples) and a Metasequoia glyptostroboides (the Dawn Redwood) which is a deciduous conifer. Pass between the conifers and you emerge on to a broad avenue. In front of you is another section of Broom Field with interesting trees such as Broussonetia papyrifera (the Paper mulberry), Sorbus sitchensis, (an American Mountain Ash) which has large bunches of fruit early in Autumn, a Quercus bicolour (an evergreen American Oak) and an Acer davidii Rosalie (one of the Snake
bark maples).Turn right down the broad avenue and continue to Post 9 which is positioned opposite a seat.
Opposite the seat is a collection of Yakushimanum hybrid Rhododendrons along with a Syringa and a Kolkwitzia amabilis (the Beauty bush), whose drooping branches are clothed with masses of bell-shaped pink flowers with yellow throats in May/June. On the left of the seat are a Sorbus sargentiana, with big leaflets and sticky buds in Spring and a Betula lenta (a Birch) whose leaves turn golden yellow in Autumn. Continue along the avenue towards the entrance and you will come to Post 10.
In Spring this area is covered with a group of native daffodils. Between here and the next Post 11, you pass on the left a notice concerning the arboretum and on the right you will see more Rhododendrons, a Picea smithiana (a Spruce with soft needles and drooping branches), and an Abies veitchii (a fir with stiff bright green foliage which turns a dark lustrous green later in the year). The cones on the Picea hang downwards whilst those of the Abies sit upright.
At Post 11 the area to the left is named Franklin after the award of the Benjamin Franklin Medal to Sir Bernard by the Royal Society of Arts in 1980. A Crataegus coccinea (the Scarlet Haw) from Eastern America, which is a thorn that has large leaves and big red fruits is behind the post. Also in this section you can find Birch, several Leycesteria (which has purple and white long racemes of flowers in summer and autumn) and Acers.
Continue to the entrance and you have now completed the short, yellow route.