Q: I am happily getting sucked into the wonderful world of houseplants, but don’t really have room for those big philodendron and monstera that seem so popular right now. I want something different from the usual spider plant, African violet or succulents. Any recommendations?
A: I have been getting more enamored with species begonias since I also gravitate toward compact and more unusual plants. Begonias are a diverse group and offer lots of attractive features to indoor plant growers. I recommend that anyone wanting to broaden their indoor plant collection check them out. You may be able to find a local begonia appreciation group to join (such as a branch of the American Begonia Society) to learn about this beautiful group of plants and how best to care for each type.
Garden center finds, often rex-type begonias, will be clumping in habit, but other species provide size versatility. Although they can be harder to source, some begonia species stay as small as a soil-hugging creeper with leaves smaller than a quarter, easily fitting in a fishbowl terrarium. Others develop tall stems that can reach several feet high without support. A few species trail and can be used in a hanging basket, while others cling to crevices in mossy rock surfaces in their native forests, making them tolerant of limited soil space. This diversity in stature allows gardeners to choose those that best fit their space or how you want to display them.
While they can produce showy blooms indoors, foliage is the primary draw for many tropical begonia growers. There are species with iridescent leaves, reflecting blue hues in just the right lighting, and others with leaf spots or splotches in silver, pink, near-black or red. Several species have colorful hairs or leaf bumps (called bullae) in colors different from the rest of the leaf, adding multidimensional appeal to the foliage.
While preferences for temperature vary, tropical begonias generally want moderate to high humidity. Achieving this indoors can be tricky, but for compact-growing species, using a seed-starting dome (the taller size), repurposing a deli container or using a cloche over the pot can trap humidity well enough to keep plants thriving. Using grow lights can help keep temperatures moderate compared to growing in a windowsill, but both approaches can work well depending on the plant.
As another point in their favor, most begonias also propagate fairly easily from leaf or stem cuttings, allowing fellow enthusiasts to share plants if you want to try new species or collect more leaf colors. It also allows you to create a backup plant in case your original one becomes stressed as you learn what it needs to thrive — a handy trait for any indoor plant .
Q: I’ve seen a few shrubs and small trees with scattered flowers on them lately — the kind that would normally bloom in spring. Why are they out of season?
A: It’s not a well-understood phenomenon, but is thought to be tied to stress experienced by the plant during summer — drought stress in particular. Plant growth, flowering and dormancy respond to a variety of environmental conditions, including temperature fluctuations, soil moisture and day length (photoperiod, or how much of a day is darkness versus light). Plants have limited access to moisture during winter while temperatures are at or below freezing, so in a sense, they are drought-stressed then as well. If plants in a home landscape weren’t being watered periodically during the drought that much of Maryland experienced this year, the modest uptick in late-season rains might trigger some flowering that would ordinarily wait for spring. Yale’s Climate Connections article “What causes flowers to bloom in the fall?” discusses this quirk of plant behavior.
Magnolias, crab apples, azaleas, rhododendrons and lilacs are examples of offseason bloomers, though among flowering cherries, there is one cultivar that normally blooms in both fall and spring (the aptly-named “autumnalis”). There are also dozens of azalea cultivars that are bred to rebloom in late summer or fall.
Nighttime lighting is another disruptor. The importance of photoperiod on plant growth and development varies across different species. The length of an uninterrupted period of darkness influences the plant’s perception of what season it is, affecting everything from height to the timing of flowering. Light sources interrupting the darkness can in effect turn a long night into a short one as far as the plant is concerned, and it might not take much in terms of light intensity or duration. Porch lighting, lamp posts, motion-activated flood lights and even accent landscape lighting might all affect how well nearby plants grow, flower and prepare for winter dormancy.
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.