How does climate change impact planting and growing?
Q: I’m interested in learning more about climate-wise gardening. Are there ways to make our plantings more resilient? Should we be gardening differently?
A: Climate change will have varied impacts on how we garden, including optimal plant choice, anticipated pest, disease, and weed challenges, and a realignment of our expectations of landscape appearance and performance.
Plant choice is something we have more direct control over. Use locally-sourced native species when possible, as they have proven themselves to be adaptable to what climate change (and the stresses of urban development that surrounds them) has already thrown at them. Plant populations to our south (Virginia) can also be useful for their greater heat tolerance. Our webpage “Native Plants and Climate Change” provides more detail.
Zone-pushing, which uses plants that are barely winter-hardy here now in consideration of the eventual warming or shortening of our winters, is less of a risky experiment as we update our gardens. Make sure species chosen have not shown invasive tendencies, however; aggressive species native further south might wreak havoc here if not kept in check by competition from thriving local flora.
Meanwhile, some of our adored plants will probably have to be left to our northern neighbors because they already struggle with our heat, like common lilac, spruce, and rhubarb. Until then, our expectations of how well these plants look and perform in our gardens should be tempered with a healthy dose of “well… at least it’s still alive.” Or better yet, replace them with something that will need less life support from the gardener.
In terms of avoiding pest or disease outbreaks, the recommended best practices are unchanged: diversity in the garden is key. A wider range of plant resources and habitat variety means you’ll attract a wider array of beneficial organisms that keep pests at bay. Competition in the web of life is everywhere, even between microbes like fungi and bacteria; what we want is to have the beneficial species out-compete the pathogens. We aid them in this endeavor by keeping the soil healthy, limiting pesticide use, and minimizing plant stress by selecting the right plant for the right place. Plus, disease damage is more easily limited when fewer vulnerable host plants are clustered together. Aesthetics and our wallets suffer less when we lose one plant out of a mixed-species planting versus a whole hedge of the same cultivar.
Lastly — you’ve seen the memes and you’ve probably heard all of the arguments, but I’ll say it again — we really need to stop cultivating so much lawn in our yards and public spaces. Yes, turf has its uses, but when not needed for high-traffic play spaces, our yards should contain more plantings of just about anything else site-appropriate. Lawn takes a lot of inputs to keep it looking good, and when it doesn’t look good, wouldn’t an easier alternative make more sense? Even when maintained in a pollution-limiting manner, lawns offer little to biodiversity. Maryland’s location in the transition zone — where neither cool-season nor warm-season turfgrasses thrive yearround — means that the outlook isn’t good for lawn care getting any easier as climate change throws us more curveballs of abnormal weather.
You can keep up with current advice as we populate our new “Climate-Resilient Gardening” resource tag on the HGIC website. Current content includes information on the basics of climate change and approaches to sustainable gardening.
Q: I have a blooming bromeliad whose flowers are just about spent. What should I expect from it afterwards? Is it going to die?
A: Sort of — part will die but it will also reproduce. The “mother” plant, the one that’s blooming now, will gradually decline over several months, with the colorful bloom dying back first. Meanwhile, if the plant was growing well before it bloomed, it’s redirecting energy into producing offsets. These are clones of itself that grow on short stems (stolons) emerging from the base of the plant, and in the bromeliad family these offsets are also commonly called “pups.”
When large enough (about a third to half of the parent plant’s size), a pup’s stolon can be cut from the mother plant and the new plant grown separately, though there is no harm in leaving them attached if you prefer. (Though eventually they may make the entire cluster tippy since the weight distribution will change as they grow and hold water. An interconnected colony of bromeliad generations is unwieldy but impressive to see.) As they mature, this second generation will bloom in due time, and then the process will repeat itself.
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.