Three highly-bred flowers of little use to pollinators, from the left, Hybrid Tea rose "Biedermeier", Pompon Dahlia 'Small World', Snowdrop Galanthus nivalis 'flore pleno'
Bedding Plants are highly hybridised annuals used in hanging baskets and tubs and planters. They are the result of breeding to create strains with uniform size, long-lasting flowers, bright colours, and a long retail 'shelf life’. Production of pollen or nectar accessible to insects has generally been lost, which is why we avoid them in wildlife gardens. Typical examples are busy lizzies (Impatiens), Petunia, surfinias (which are a type of Petunia), bedding “geraniums” (Pelargonium hybrids), Nemesia, double flowered ‘French’ and ‘African’ marigolds, Celosia, Begonia, and Ageratum. The brightly coloured winter-flowering Polyanthuses and winter-flowering Viola also fall into this category.
There are a few exceptions. The following kinds of bedding plants are commonly visited by foraging insects: sweet alyssum (Lobularia), single-flowered nasturtiums (Tropaeolum majus), wallflowers (Cheiranthus), Tagetes minuta, and Bidens ferulaefolia, a small yellow flower often used in hanging baskets. Single-flowered forms of ‘French Marigolds’ also provide food for foraging insects, but can be difficult to obtain unless you grow them from seed yourself.
In some parts of the world, especially in the southern hemisphere, many species of plants are not pollinated by insects at all but by birds, or in some cases small mammals. They are generally inaccessible to British pollinating insects. The following genera, common in UK gardens, are typical examples of this group: Fuchsia, Phormium, Callistemon, Crocosmia, Crinodendron, Embothrium, Kniphophia, Canna, Desfontainia and Cuphea. There are some exceptions , and a few varieties of Fuchsia and Kniphophia produce copious amounts of nectar that is collected by honeybees, but it is only the adaptable and adventurous honeybees and the commoner species of bumblebees that are able to exploit these flowers.
Plants to avoid because they are invasive and difficult to control
The word ‘invasive’ is often teamed up with ‘non-native’ or ‘alien’, implying that there is an association between the two terms. The vast majority of non-native plants grown in UK gardens are not invasive. Conversely there are native plants like bracken, nettles and bramble which are extremely invasive and a problem for gardeners and nature reserve managers.
Nevertheless, there is particular and justified concern about a subset of non-native plants which are causing great concern in Britain and other countries. In the British Isles this is reflected in separate national legislations which prohibit causing any of three nationally divergent set of plants to grow in the wild. The land and freshwater species concerned are listed in the Wildlife and Countryside Act
. Note that by no means all these plants are alien to all of Britain. Water Soldier (Stratiotes aloides
) which is banned in Northern Ireland is native to Southern England where it is classed as Near Threatened on the Red Data List.