Every year we grow anemones and ranunculus. Both are a cool-season crop and produce multiple blooms per plant. Few spring cut flowers can rival their flower size and color making them an early staple here on the farm.
In our zone 5/6, the winters are too harsh, so we treat them as annuals with the same growing methods. Lower temperatures are needed for growth (mid to high 50F range is best) with protection from freezing temperatures (25F or below). They will not tolerate long periods of warm and hot days (70F or above). Under these conditions, the plants are short-lived and produce less desirable blooms.
If you are in the Northern US wanting to grow outside, hold on to your corms. Store them somewhere cool and dry. I have used my pantry, basement or an old garage that doesn’t freeze. Wait until late winter or early spring to plant. Late winter is 4 to 6 weeks before spring thaw begins. This could be any time between February to May, depending on your climate. I like to use Valentine's Day as a good time to get them started here. Zone 7 or above can plant outside in the fall.
To get them started, soak for about 4 hours before planting. Corms arrive dry & shriveled. Once hydrated, they will double in size. This will allow for them to come into growth much more quickly. Excessive soaking will make them rot.Pro tip! Pre-sprout or pre-plant your corms inside while the chance of frost still exists outdoors. Any small pot with a drain hole at the bottom will do the trick (like a yogurt container with a puncture hole). We use the trays as seen below because we grow in larger numbers, see bottom of article for what we use.
Place a general all-purpose potting mix into the bottom of your container, then corm, allowing for 2 inches of potting mix to top off the corm. Keep potting mix moist but not soggy. Blooms will show a few weeks earlier. Pre-sprouting them in late February or by the first day of spring can give a jump start for when planting is ready outdoors.
Select a location so they can receive full sun. The growing area should be well drained and receive good air circulation. With a maximum growing height of approximately 14-18 inches, consider working these plants into the front border of a garden landscape.
Plant your corms when the soil is fairly dry. Wet soil packs tightly and slows plant growth. If you can crumble the soil between your fingers, it is dry enough for digging and planting. Plant to a depth of 2-3” at 6 inches apart. If you have room, ranunculus can be spaced to 9” a part. 
A general practice is to apply 2-3 inches layer of compost and organic fertilizer into the soil. This will help to replenish the nutrients extracted during the growing season.
A general practice is to apply 2-3 inches layer of compost and organic fertilizer into the soil. This will help to replenish the nutrients extracted during the growing season.
Pro tip! The key to healthy plants is healthy soil. Test your soil. Most test results make recommendations based on your garden’s needs that will help to resolve imbalances like pH level or nutrient deficiencies. When these elements are out of whack, your plants do not have access to the nutrients they need to grow. University of Massachusetts Amherst is our local source.
Anemones and ranunculus can also be grown in pots to enjoy anywhere. We recommend 1 plant per 4” pot or multiple if you have a larger container. Once they start to sprout, they need full sun and protection against freezing temperatures. Potting mixes are formulated for ideal growing conditions, so they are ready to plant. Some contain fertilizers mixed in, check the label.
Harvest when you see full color. The above picture shows the angle that flowers should be cut for optimum hydration. 
As the temperatures start to rise, plants will begin to yellow and die back. They are preparing to go dormant until cool weather returns. Once the plant looks dead/dried, then pull it out, trim back foliage, clean the corm, let it dry, store in a paper bag with vermiculite or peat. Avoid moisture, sunlight and temperatures below 50F or above 70F. Do not store more than two or three layers deep. Deep piles can generate heat and decay (like composting).
In zones 8-11, they may be treated as perennials, after the foliage has passed, cut foliage down to soil level and leave corms in ground. 
If you find your bulbs are under furry pressure, check out this article from The Spruce for defense tips.
Watch us pre-sprout corms here!
For supplies, here's a list of everything we use to get started:
You can purchase corms in our online shop here.
We hope you enjoy the fun, beauty and grandeur in your garden!
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Barbara
November 06, 2023
Thank you for this helpful post. I just received the ranunculus corms I purchased from you. Looking forward to starting them around Valentines Day next year (I am in Shelburne, MA).