Across:
8 Planted (BURIED) underrated roses individually on summits (‘underrated roses individually’ on summits = -URI-) in one of the garden areas (bed = -B-ED) (BURIED),
9 Take off (CHOP) with woman (SUE-) with ponytail (‘pony’ tail = -Y) (CHOP SUEY) and dishy Chinese style (CHOP SUEY),
10 Took advantage (USED) of some gregarious educationalists (some ‘gregarious educationalists’ = USED),
11 One of those singled out (IDENTIFIED) is similar to 13 down (‘pointed out’ = IDENTIFIED),
12 Jaguar (CAR-) cat (-PET) (CARPET) in ground cover (CARPET),
14 Bail into (bail into = LIBATION) complex (= anagram indicator) for a drink (LIBATION),
15 Thinking something over (BURIED IN THOUGHT) with 8 across (‘buried’ = BURIED) can be popular (IN) on reflection (reflection = THOUGHT) (BURIED IN THOUGHT),
18 Get engaged (SWTICH ON) to sorceress (-WITCH) taken in by family member (son = S- ON) (SWITCH ON),
20 Sir Galahad removes rags (‘Sir Galahad’ removes ‘rags’ = ilahad = DAHLIA) and consigns to the plot (DAHLIA),
22 Buy and Sell (TRADE) fingers (NAMES) (TRADE NAMES) those symbolic types in business (TRADE NAMES),
24 Snap (snap/photo = SHOT) at the end of 17 down (‘had a shot’ = SHOT),
25 Views (THOUGHTS) hardwearing type (T-OUGH-) around hotel (-H-) opening for the (opening for ‘the’ = -T-) start of season (start of ‘season’ = -S) (THOUGHTS),
26 Carried out (OBEYED) flower (flower/river OB-) covering the Iris (-EYE-) – it could be dead (-D) (OBEYED).
Down:
1 Old European kingdom (Prussia) loses head (p) (‘Prussia’ without ‘p’ = RUSSIA) with Georgian neighbour (RUSSIA),
2 Heresy coming out of Derbyshire (‘heresy’ coming out of ‘Derbyshire’ = drbi = BIRD) and Turkey? (BIRD),
3 Made a scene (A-CTED) over theologian (Doctor of Divinity = -DD-) and one (-I-) (ADDICTED) who is compulsively dependent (ADDICTED),
4 Part of stomach exercise (part of ‘stomach exercise’ = ACHE) leads to a twinge (ACHE),
5 Nerve centre (hub = H- -UB) takes in far too much (far too much = over the top = -OT T-) (HOT TUB) from Bath (bath = HOT TUB),
6 Someone who is easily manipulated (A SOFT TOUCH) by a (A) source of easy money (SOFT TOUCH) (A SOFT TOUCH),
7 It’s huge (BEHEMOTH) for Elizabeth (BE-TH) getting over the border (-HEM-) for nothing (-O-) (BEHEMOTH),
13 Revealed (POINTED OUT) the essence of the argument (POINT-) by journalist (-ED) is public knowledge (OUT) (POINTED OUT),
14 New (-N) bar (LINE-) opens (= positional indicator) (LINEN) for the retiring types (LINEN for those retiring/ going to bed),
16 Disreputable (UNWORTHY) organisation (UN-) linked to noble (-WORTHY) (UNWORTHY),
17 Sounds like (= homophone indicator) one released Bullitt (“one released Bullitt” = “one released bullet” = HAD A SHOT) and went for the big time (HAD A SHOT),
19 Sample of catch on shuttle (sample of ‘catch on shuttle’ = HONSHU) in Japanese waters (HONSHU – largest of the four main Japanese islands),
21 Did some pressing work (IRONED) for Oscar (-O-) in new (= anagram indicator) diner (diner = IR- NED) (IRONED),
23 Disorder (MESS) in meaningless banks (‘meaningless’ banks/sides = MESS),
24 Some powerhouse engineer (some ‘powerhouse engineer’ = SEEN) in the public eye (SEEN).