Are Cultivars Good For Wildlife?
Double Blooms
Certain flower varieties offer an 'attractive' double bloom. Double blooms are the result of a genetic mutation that causes extra petals to develop from the reproductive organs. Although these flowers may be pretty to us, for pollinators this transformation is bad news!
Many pollinators feed exclusively on pollen. Pollen comes from the stamens, and if these are transformed to petals, these pollinators have no food (or at least much less since not all stamens are necessarily converted into petals).
Flowers may also produce nectar--a sugary fluid secreted by the plant in order to attract pollinators and thus a good source of energy. The nectar producing organs are usually located at the base of the flower. However, the presence of the extra petals makes access to the nectar more difficult if not impossible.
Many pollinators feed exclusively on pollen. Pollen comes from the stamens, and if these are transformed to petals, these pollinators have no food (or at least much less since not all stamens are necessarily converted into petals).
Flowers may also produce nectar--a sugary fluid secreted by the plant in order to attract pollinators and thus a good source of energy. The nectar producing organs are usually located at the base of the flower. However, the presence of the extra petals makes access to the nectar more difficult if not impossible.
Sterile Hybrids and Mutations
Certain varieties offer flowers that are both showier and longer-lasting than the original plants they were bred from--however, they are sterile.
Plant hybrids are the result of sexual reproduction between plants from two different species. Although not all plant hybrids are sterile, many are.
1) Itoh hybrid (in think no viable pollen so yes to food source)
2) mutation sunflower (no pollen at all!)
Now, you could reason that this is no issue since many plants can propagate vegetatively and the longer bloom period could offer a longer feeding period for pollinators.
However, genetic traits are often bunched and sterile varieties studied thus far show significantly lower nectar and pollen production.
Furthermore, sterile varieties means no seeds will be produced, and thus cutting off the food supply for other animals (e.g. birds).
Plant hybrids are the result of sexual reproduction between plants from two different species. Although not all plant hybrids are sterile, many are.
1) Itoh hybrid (in think no viable pollen so yes to food source)
2) mutation sunflower (no pollen at all!)
Now, you could reason that this is no issue since many plants can propagate vegetatively and the longer bloom period could offer a longer feeding period for pollinators.
However, genetic traits are often bunched and sterile varieties studied thus far show significantly lower nectar and pollen production.
Furthermore, sterile varieties means no seeds will be produced, and thus cutting off the food supply for other animals (e.g. birds).
Variegation & Leaf Colour Alterations
as the percentage of variegation increased, the leaves became less attractive.
“Red leaves remove chlorophyll from the leaf and load it with anthocyanins, which just happen to be feeding deterrents.”
“Red leaves remove chlorophyll from the leaf and load it with anthocyanins, which just happen to be feeding deterrents.”
Nativars, 'Natural' Cultivars, and Viable Hybrids
In this section I will talk about plants that have been selectively bred for certain traits and viable hybrids.