Q.What does half annual mean
We have some calendula seeds and it says they are half annual. What does this mean?
Well-l-l-l, that's a bit of a puzzle. Calendula are annual plants, meaning they grow, flower, and make seeds in one season (year.) Some plants are biennial, meaning they spend their first year growing, and the second year producing flowers and making seeds. Half annual, or semi annual, means 1/2 a year, or every 6 months; it can refer to interest compounding, or magazine publication , but I've never seen any reference to half annual being applied to plants of any kind. Now, some varieties of calendula are described as half double, so perhaps there's a misprint on the label. In case there are other errors, here's a piece on calendula: https://www.gardeningknowhow.com/ornamental/flowers/calendula/growing-calendula.htm