The answers are items found in the garden (not just plants)
1. Cow's name (9) 2. "Victory" cost 5400 of these (3,5) 3. Castle shape (4) 4. 19th century military adornment (5) 5. Shame (6) 6. Regency cat (9) 7. Dull tree for a capital (6,5) 8. Feline relative (6) 9. Iller than ever (8) 10. Earthy wise man (6,5) 11. Two wheeled transport for males (8)