
Answer
Dear Andrew,
Dianthus barbatus or sweet william is a biennial to perennial plant that only blooms during its second year of life. Regularly hoeing the plants in the spring before they flower should stop them from spreading and deplete the seed bank.
In addition, regular mulching (covering the space between the vegetables with a layer of compost) of your vegetable garden helps against weeds and also provides your vegetables with extra nutrients.
Answered by
drs. Marc Reynders
Biology, systematics and evolution of seed plants. Specialized in tropical Cyperaceae.
http://www.ugent.be
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