Cool Plants, Cool Temperatures

My least favorite aspect of this area is the cold winter preventing us from growing plants that are more characteristic of tropical and desert zones. However, I’ve discovered certain plants have unique cultivars that make it possible for us to grow them in our frozen landscapes year-round. Two of these plants can even be visited here at Wellfield! 

I will start with the plant that I discovered in the Gardens, hardy begonia (Begonia grandis). It is pretty common to see begonias as potted plants and bedding annuals in our area. Guests have mistaken it for a bedding annual in the past, but this plant is a perennial in our area. It grows from a tuber underneath the soil, and the tuber survives even though the foliage will die back like other perennials. It gives an exotic look and looks great next to other large leafed tropical-looking plants like hostas. The leaves are large for a begonia, and the underside of the leaf is solid red. If you want to come check one out in the Gardens, look for them in the Lotus Creek Garden.

Herbs are some of the most fun parts of gardening because it is easy to grow them, and they are easy to store for winter after drying. It is so disappointing that some commonly used herbs are unable to survive our winters. But get ready to add another plant to the year-round herb garden: rosemary (Rosmarinus officinalis/Salvia rosmarinus)! The cultivar name of this rosemary is ‘Arp’ rosemary and amazingly, it can be grown here. It is evergreen and grows into a nice shrub with blue flowers. Best of all, it is delicious! This cultivar is hardy to USDA zone 6 so it may have cold issues depending on microclimate and would benefit from some extra winter protection. I only discovered this plant three weeks ago, but I am already trying to see if it is something we could bring to Wellfield.

For the epitome of a tropical look, a banana tree would be perfect. Unbelievably, there are cold hardy banana trees. The largest of these hardy banana trees is Musa basjoo. It does not stand tall the whole winter. It reacts the same way that our other perennials do; it dies back to the ground and rises back up in the spring. It still tends to be beneficial to add a pile of compost or mulch on the ground where the banana is planted. It is native to Japan and can handle as cold as USDA zone 5 or 6. It still loves a ton of sun, so make sure it is in a spot that gets a lot of light. It grows quite tall in a season, so make sure it has enough room if you attempt to grow this massive perennial.

The last interesting plants I want to let everyone know we can grow around here are in the cactus family! The cactus family is one of my favorite groups of plants (they are all kind of my favorites). Indiana has one native species of cactus, Opuntia humifusa, also known as eastern prickly pear cactus. I have written about cactuses a few times since starting here, so it may not be surprising that I bring it up again. The flowers are massive and beautiful. The natural growing opuntia in Indiana have long spines, and I found that out the hard way when it went through my shoe! They are also called low lying prickly pear because they crawl along the ground and do not grow upright like a lot of the southwestern species do. Opuntia fragilis is another species that grows just over the border in Michigan. It is called brittle prickly pear and like all cactuses, has a large beautiful flower.

Studying plants that normally should not grow in the snow is something I have been looking into for a while. I hope I managed to bring some cool ones to your attention – maybe you can use some of these to brighten up your landscape or make your summers feel more tropical.

Cody Hoff, Lead Horticulturist