Recent reports from the BBC suggest foreign insects are having a big affect on the UKs plants.
Among the culprits is the Thaumetopoea processionea, or oak processionary moth, which is native to central and southern Europe.
Its caterpillars feed on oak trees and contain toxins which can irritate the skin and cause allergic reactions.
Another pest for gardeners to be worried about is the rosemary leaf beetle.
Coloured a metallic green with bronze stripes, the beetle feeds on rosemary, lavender and other related plants, stripping the leaves from them, according to the BBC.
The bug was first spotted at the Royal Horticultural Society (RHS) gardens in Wisley but has now spread nationwide.
Others to look out for include the Cameraria ohridellais, which destroys horse chestnut and the red lily beetle, which devours lilies.
The lily beetle is described as the lily growers nemesis by RHSs Andrew Salisbury.
Gardeners who spot any of the insects are being encouraged to report the sightings to the relevant authorities to help prevent further damage.