Euonymus invader

Q What’s this brown and white substance on my euonymus?

A Your shrubs are infested with sap-sucking euonymus scale insects. The males are white and females blackish-brown. June and September are the best times to spray, but if plants are badly affected, try treatment now. If you garden organically, spray with a pesticide based on plant oils, fatty acids or pyrethrin, such as Doff Greenfly & Blackfly Killer £2.92 for 1L spray); or Ecofective Bug Killer (£9.99 for 1L). If you’re comfortable using chemicals, choose a spray such as Resolva Bug Killer (£9.99 for 250ml) or Provado Ultimate Bug Killer (£4.79 for 1L). Spray on a dry day and make sure the treatment reaches stems and leaf undersides.

QI drained my pond to make a flower bed. Why does it keep refilling with water?

A Many years of soil compaction under the liner may have formed an impermeable layer in the soil. Try forking over the sides of the pond to see if you can break up this waterproof layer. It’s worth considering that the pond might have been put in this area to solve an existing problem of poorly draining soil. If it’s naturally wet and water drains into it, you might have to admit defeat and create a bog garden instead.

Q Why are laurel leaves full of holes?

A Your laurel is infected with shothole disease, which is impossible to cure. If you feed and water the plant, it could survive for many years, but will never shake off the problem completely.