你可以在本地苗圃或园艺中心购买种子，也可以在网上购买。 选择向日葵品种。 挑选大小合适的容器。

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You can buy sunflower seeds from your local nursery or garden center, or you can order them online. If you want rarer varieties, you may have better luck online. Dwarf varieties are best-suited for container growing.  Sunflower seeds are also sold in grocery and convenience stores, but these are for eating, not for growing. After being roasted, a sunflower seed won't sprout. If you already have a fully grown sunflower plant, put the seeds from the flower in an airtight container and keep them in the fridge. Try to plant the seeds as soon as possible. Older seeds may be harder to grow. A packet of sunflower seeds (or a listing on a website) will clearly state the name of the variety, the type of sunflower it is, and how tall the sunflower will grow. If you're shopping at a local nursery or garden center, you can also ask an associate for help.  Single-stem sunflowers only grow one flower from one seed. If you want to keep sunflowers all summer, you'll have to replant every 10 to 14 days. However, single-stem varieties are pollen-less, so they won't drop pollen on your porch, furniture, or clothes. Branching sunflowers produce many flowers over the course of the season without having to be replanted. Branching sunflowers also have some of the more unusual colors, including burgundy and chocolate. Choose the size of your container based on the height of the flower you want to plant, as well as how many flowers you want in each container. Generally, most dwarf sunflowers can be planted in a 12 to 16 in (30 to 41 cm) pot.  Mammoth sunflowers need a container that holds at least 5 gallons (19 L). If you're repurposing a container that was previously used for something else, make sure it's clean and sterile. You may also have to make drainage holes in a repurposed container. Without them, your seeds may rot. Include a plate or saucer under the container to catch run-off water.