Can I get a tropical garden aesthetic in Maryland?
Q: I’m a relative newcomer to Maryland but have always been attracted to the garden aesthetic of tropical-looking plants. I realize we get too cold for most tropicals to survive outdoors, but is there a way I can get this look using hardy plants? A: Definitely, if you’re in one of the Piedmont or Coastal Plain counties (most of the Baltimore region), and a couple are even native (or nearly so). Most of the tropical vibe comes from large foliage, but sometimes vibrant colors and larger flowers enhance the atmosphere. I’ll focus on foliage since that’s the more limiting group.
As it gains popularity you may already be familiar with Pawpaw (Asimina triloba), our local native fruit tree that thrives in a wooded understory and which has relatively large leaves. A less well-known candidate with even bigger leaves is one of the aptly named bigleaf magnolia species. Bigleaf magnolia (Magnolia macrophylla) isn’t part of Maryland’s native plant community specifically but does grow here, and will probably be easier to find than umbrella tree (M. tripetala), whose occurrence in the state is natural but rare. Even our native cucumber tree (M. acuminata) has leaves that can be on par with pawpaw foliage.
For the zone-pushers out there, a handful of short palm species can survive our average winter temperatures. The odds are becoming more in their favor due to warming winters. These include windmill palm (Trachycarpus fortunei) and needle palm (Rhapidophyllum hystrix).
You might be surprised to learn that there’s a winter-hardy banana that you can grow in Maryland. It’s not used for fruit, but has the same human-sized leaves and certainly makes a memorable impression. Technically an herbaceous perennial because it doesn’t form a woody trunk, Japanese fiber banana (Musa basjoo) becomes the size of a small tree, dying back completely over the winter but growing quickly enough to regain its full height again by summer. A bit of extra winter mulching can help the crowns deal with cold, and I’ve seen it overwinter in southern Pennsylvania and eastern Connecticut. When thriving, they can actually be a bit of a garden bully, spreading into a wider colony. To be fair, so can Pawpaw when it suckers.
Reports vary on the hardiness of golden lotus banana (Musella lasiocarpa), but it tends to be okay with our winters if they’re mild, especially given the advantages of a microclimate. (I’ve seen it overwinter in D.C.). A cousin of banana, this shrub-sized standout has large leaves trending bluish and big yellow flowers that resemble a pointed-petal lotus. The leaves are stiffer and stay more intact than those of banana and may remind you a bit of bird-of-paradise. Try one and challenge your plantnerd friends to identify it.
Beaked yucca (Yucca rostrata) is another delightfully incongruous plant whose overall appearance contributes a bit of a palmlike feel, although it’s a true yucca, just taller than we’re used to seeing. Slowly developing a “trunk,” the starburst of bluish foliage brings a great point of contrast to typical garden plants. A native of Texas into Mexico, it can grow well here (I’ve seen this one in southern Pennsylvania too) as long as it gets good drainage.
Q: Should I be worried about my vegetable garden’s autumn cover crop becoming a weed? Will they seed all over the place?
A:
Usually not, because either they die over winter (and their debris serves as mulch) or they are terminated (mowed-down or removed) either during bloom or just after bloom and prior to going to seed in spring (mid- to late April in central Maryland). Occasionally a few can escape cultivation and pop up in natural areas, but currently not to the extent that they are invasive. You can learn more about the use of cover crops and the timing of sowing and mowing on our Cover Crops for Gardens page.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension. umd.edu/hgic. Click “Ask Extension” to send questions and photos.