Across
1 Tree popular in the present day market. (9)
6 Cook dill and spy insect - that's galling! (7)
9 Fungus causing timber to get complaints first. (9)
10 No sense can be made from inner core of Laburnum branch. (4)
11 Broken eyebolts Toby took out - they're slippery. (4)
14 Maples perhaps, seen through windows between beginning of January and end of June. (8)
16 Feathered tree nursery. (4)
17 Contrive 5837 tree constraints for example. (4)
19 Hornbeam leader died back - it was the bad weather. (6)
22 Element of resistograph. (5)
24 Ginkgo fruit is finally thus by George! (6)
25 A handy tree. (4)
26 Evergreen, Ilex for example, displays flower. (4)
28 The Plane can be mistaken for this species noted for its tendency to develop a long trunk. (8)
30 Female Redwood. (4)
34 Enthusiastically involved in lopsided reduction of Pin Oak - training leader included. (4)
35 Listen! Reason commonly given on applications to fell protected trees is a non-starter. (9)
36 Dissect trees to find tight spiral arrangement of leaves. (7)
37 Stand type of European on platform. (9)
Down
1 Tree - prune around older branch nodes initially. (6)
2 Green grime mistaken for perennial. (2-8)
3 In Thujopsis aloft with rope. (5)
4 Bearing of Fir found around the East. (4)
5 Timeless Spruce woodland creature. (4)
6 Fruit from two trees. (9)
7 The French prohibition order on Cedar. (7)
8 Climbing aids for Jeremy perhaps. (5)
12 Climbing from bottom of Lindens to remove branches. (4)
13 Willow, very big one on outskirts of Esher. (5)
15 Erotic, topless - rub up in garden. (6)
18 Small particle found in Tilia tomentosa. (4)
19 He could be said to be rash for creating UKTC (6)
20 Broom with more explosive power than Harry Potter's Nimbus 2000. (4)
21 Tree inhabiting insect - larva up in one badly affected. (10)
22 Some leaves are thus arranged o'er stem, not right away though. (9)
23 Shigo's proposal to Princess in bed. (5)
24 Said to relinquish fertilized ovule. (4)
25 First of tissues to be extracted from pipetted culture reveals amino acids. (7)
27 River's Beech made Hendrix misty eyed. (6)
29 Nothing found at end of branch - so nothing to do. (5)
31 Spiraeas scattered around airless church recesses. (5)
32 Hear cat cry quietly - this could provide the means of rescue. (4)
33 Eggs layed on leaf tip - a particular sort of leaf. (4)