Think Big!

Large annuals may be just what you need in certain spots in the landscape. They can add some height to a flower garden. You can also get more for your money by filling up a large space with just a few plants. Large perennials, like grasses, could also be used for these purposes. These are great because they come back every year, but unlike annuals they take more than a year to reach their full size.

Here are a few impactful annuals that we’ve grown at Minnetrista.

Castor Beans—Spend a little and get a lot! Castor beans are easy to start from seed, so I’d recommend buying a packet. Amongst the columns at Minnetrista’s entrance last summer, these plants made quite an impact. Find out more about starting castor beans from seed.

Castor beans growing at the Columns at Minnetrista.

Here you can see that the castor bean's leaves are much larger than my hand.

Alternanthera ‘Purple Knight’—This plant with attractive purple foliage may be on the smaller side, but ours got at least 3 feet tall growing along the wall in The Orchard Shop Courtyard. I was very impressed by the size it reached by the end of the summer.

Shiso—This edible herb that can be started from seed has beautiful foliage. My favorite variety is ‘Britton.’ Its dramatic leaves are green with red undersides. Expect it to reach between 3 and 4 feet tall by the end of summer.

Here's Britton shiso early in the season before it has reached its mature size.

Orange gem marigolds look good against the foliage of red shiso.

Bananas—If you want to create a tropical feel, try growing a banana. Large plants might be on the expensive side, but keep in mind that you can bring bananas inside during the winter. So that initial investment could potentially last for years. Don’t expect to get any fruit though—our growing season isn’t long enough. Visit Northern Tropics, a local nursery, this spring. They will have available hardy and tropical bananas, as well as ensete, a banana relative. Find them online.

We overwinter our bananas in a cool basement.

Cardoon—This thistle relative has beautiful silvery green leaves, but beware their prickles. The cardoon we planted at the columns reached around 3 feet tall. We started this one from seed too.

From front to back: mums, kale, and cardoon.

Pennisetum ‘Princess Caroline’—This dark purple, almost black grass reaches 2–3" tall and 2–3" wide. Oranges, reds, and purples will really pop against its foliage.

All of these annuals love full sun. Try combining some of them with brightly colored annuals. If you do, I think you’ll be rewarded with a setting that looks lush and feels almost tropical.

Pennisetum 'Princess Caroline' at the Catalyst at Minnetrista.