A fun control option for runaway plants: Arrange them! How do I keep my patch of Italian Parsley from spreading too far? I create bouquets with the flowers before they have a chance to set seed. Since it’s a biennial, I always need new plants to come up to ensure a good supply of this useful herb. Being a biennial, the leaf production is strong the first year. The second year it produces stalks and flowers at the expense of leaves– then it dies. So I do leave a few flowers to go to seed. Other biennials and short lived perennials I treat similarly—Chrysanthemum parthenium (feverfew), Digitalis lutea, Lychnis coronaria, Verbena bonariensis, Verbascum bombyciferum (mullein), Aquilegia alpina (alpine columbine).
My woodland has hellebores galore now, thanks to prolific seedlings. This winter will be the first year they are deadheaded. Hellebores are wonderful indoors. In winter, the cheer of a floral arrangement lightens the grey, short days and bringing the flowers indoors translates into less crowding in my already full woodland.
There’s no stopping plants that spread vegetatively by the roots or little bulbs by removing all the flowers, but it helps whittle down the seed bank–a helpful start for keeping that Alstroemeria (Peruvian lily) of mine from popping up and reigning over another bed. A staple of the floral trade, this is a natural for the vase.
Thalictrum flavum var. glaucum (meadowrue) always turns into a bouquet, otherwise it seeds everywhere. Interestingly enough, using it in bouquets takes care of its fruitful tendencies. My 10 year plus clump hasn’t ever needed dividing and it hasn’t run by the roots.
Solidago ‘Fireworks’ (goldenrod) is in its third season in my garden and this year the carpet of seedlings around the original plants is duly noted. In a few weeks, when the buds crack—into a splendid bouquet all the flowers will go!
© Colleen Miko, 2011