Every year, staff and volunteers at the Kemper Center for Home Gardening field thousands of questions from people all over the country, world, and as close as down the street.
Each year, some questions seem to stand out more than others. Here are six of the most frequently asked questions of 2024.
1. How will periodical cicadas impact my garden?
In the spring of 2024, the St. Louis region was treated to the emergence of the Great Southern Brood XIX periodical cicadas. These cicadas spend 13 years underground before emerging en masse in the spring to molt, call, mate, lay eggs, and then die.
Questions regarding the emergence of the Brood XIX periodical cicadas started coming in as early as February and continued until around mid-summer.
To learn more about periodical cicadas including answers to frequently asked questions, details on their life cycle and more, check out this blog post from the Sophia M. Sachs Butterfly House as well as our cicada information page.
2. What is wrong with my Azaleas (Rhododendron)?
Azaleas (Rhododendron), particularly evergreen azaleas, have had a rough few years in the St. Louis area, and the winter of 2023-2024 did not help.
A cold snap in January subjected gardens in our region to temperatures around -7°F with a gusty north wind. Combine that with a similar cold snap in December of 2022, as well as less than ideal growing conditions such as clay soils, alkaline soils, and drought, and you create a stressful environment for azaleas.
Plants with poor vigor, reduced flowering, dieback, or discolored foliage were a routine topic of discussion at the Kemper Center, particularly in April when they would normally bloom. Stressed azaleas are also more susceptible to damage from lacebugs, thrips, and spider mites.
For more information about growing rhododendrons and azaleas in the St. Louis region, check out our FAQ page.
3. How do I start Rainscaping?
Above average rainfall in July of this year prompted many people to ask for advice on rainscaping.
Rainscaping with native plants can provide many benefits including reducing the amount of storm water that enters sewer systems, controlling erosion, and providing habitat to animals and pollinators. This blog from the Garden’s Sustainability Division and the Kemper Center for Home Gardening provides a good beginners guide to rainscaping.
A more detailed step-by-step Rainscaping Guide is also available online.
4. Why do my Hostas have holes in them?
Late spring and early summer saw many reports of hostas with holes in the leaves and no obvious culprit.
Nocturnal feeders such as slugs, variegated cutworms, and pill bugs were primarily to blame, although hail damage to hostas was also reported.
While gardeners have few options to improve the appearance of their hostas once the damage is done, the long-term health of the plants is rarely impacted by this kind of damage.
Check out our Visual Guide to Hosta Problems for more information.
4. How do I keep deer out of my garden?
How to find plants that these large herbivores will not mow down is a common question at the Plant Doctor Desk, usually followed by an exasperated sigh.
The truth is that they will eat anything if they are hungry enough, and areas with an overpopulation of deer (including the suburbs and exurbs of St. Louis) often see the highest feeding pressures throughout the year.
Repellants and scare devices can work for a time, but fencing is the only consistently effective control measure. For more information, see our deer information page.
5. How Can I Keep harlequin bugs Out of My Vegetable garden?
Harlequin bugs are colorful stink bugs with piercing-sucking mouthparts that can cause damage to a range of ornamental plants and vegetable crops, though brassicas such as cabbage and kale are some of their favorites.
Adult harlequin bugs will overwinter in weedy debris, leaf litter, or mulch and emerge in the spring to mate and lay barrel-shaped, black and white striped eggs.
Keeping the vegetable garden clean can reduce the population of overwintering adults, and removing eggs, nymphs, and adults as they appear during the growing season can help protect vulnerable crops.
For more information, read our harlequin bug information page.
We’re here to answer your gardening questions
The Kemper Center for Home Gardening is here to answer your gardening questions. Whether you visit us in person, call us, or email, we will connect you with information and resources to help make your garden the best it can be.
Plant Doctor
Expert Garden staff and Master Gardener volunteers are available in person to answer your gardening questions. This walk-in service is available free with admission. Please leave plant material at home if you plan to visit to keep our collections safe.
- April – October: Open 7-days a week, 9 a.m. – 3 p.m.
- November – March: Monday – Friday, 9 a.m. – 3 p.m.; Closed weekends
Horticulture Answer Service
Garden staff and Master Gardener volunteers provide personalized answers to your specific gardening questions over the phone or through email.
- Hours: Monday – Friday, 9:00 a.m. – 12:00 p.m.
- Phone: 314-577-5143
- Email: plantinformation@mobot.org
For more information including a wide range of online resources, visit our Help for the Home Gardener home page.
Justine Kandra | Horticulturist with the Kemper Center for Home Gardening
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