(Image credit: openclipart.org, artist jhnri4. Used under the Creative Commons Zero 1.0 License.)
Our horticultural help desks, in our obviously unbiased opinion, are fantastic tools for sharing gardening knowledge. The main help desk is staffed by Piedmont Master Gardener volunteers and can be reached at albemarlevcehelpdesk@gmail.com or 434-872-4583. Walk-ins are welcome! The Help Desk is located at the Virginia Cooperative Extension office in the Fifth Street Extended Albemarle County Office Building (460 Stagecoach Road). Hours are Mon./Wed./Fri. 9 AM – noon from October 15 – March 15, and daily 9 AM – noon the rest of the year.
We also have help desks at the Charlottesville City Market (1st/3rd Saturdays), the Crozet Farmer’s Market (2nd/4th Saturdays), and events like the Albemarle County Fair and our Spring Plant Sale. Our Events Calendar has information about these and other PMG goings-on.
What kinds of questions do we field at the Help Desk? In other words, what are the main issues faced by gardeners in our area? We use a “ticket” system to record questions and responses at our main help desk. The chart below shows the number of tickets in the 50 most common categories of questions. For the top 10, here are some brief thoughts, as well as links to resources:
10. Pruning and deadheading are critical for appearance and health. The health benefits can’t be over-emphasized! Pruning creates space for airflow around leaves and branches, reducing dampness and fungal growth. Prune to remove diseased areas, preventing pathogen spread. Finally, pruning can remove broken, awkward (i.e. likely to break), and rubbing branches. Deadheading is less critical for health, but can extend flowering seasons.
Keep clippers and saws sharp and clean. Disinfect with a 70% rubbing alcohol solution.
Resources:
Pruning Basics and Tools (VCE publication 430-455)
Pruning Deciduous Trees (VCE publication 430-456)
Pruning Evergreens (VCE publication 430-457)
Pruning Shrubs (VCE publication 430-459)
Stop Topping Trees! (VCE publication 430-458)
9. Weed control should use methods appropriate to the problem. Don’t pull out the flamethrower for some ground ivy – just pull it up, if possible. If chemicals are absolutely necessary, use Integrated Pest Management (IPM) techniques. When using herbicides, always follow the directions on the label and use personal protective gear.
Timing is key to weed control, regardless of method. Apply pre-emergent herbicides before, well, emergence. Remove flowering weeds before they go to seed. It’s always easier to tackle a few weeds now than to wait until they’ve spread (easier said than done, of course).
Resources:
2021 Pest Management Guide – Home Grounds and Animals (VCE publication 456-018)
Virginia Tech weed identification website
Noxious Weeds (Virginia Department of Agriculture and Consumer Services)
Pests in Gardens, Landscapes, and Turf: Weeds (University of California Integrated Pest Management)
8. Leaf spots have many causes: fungal and bacterial diseases, mites, and insects like aphids and thrips.
The bad news is that once leaf spots appear, often little can be done. Prevention is better: remove dead plant material at the end of the season, prune to prevent dampness, and don’t wet leaves when watering. The good news is that leaf spots often are benign. Maple trees in particular are prone to “zonate leaf spot” in late autumn, after the leaves have done their job.
To identify causes and suggest remedies, we need the following: species/name, when spots appeared, environment (e.g. shady/sunny/moist), and clear pictures of the spots and the entire plant. We can look at samples under a microscope in the VCE office.
If needed, we can send samples to Virginia Tech’s Plant Disease Clinic for diagnosis. The cost is $35. A proper sample is essential! Collection instructions are towards the bottom of this website.
Resources:
2021 Pest Management Guide – Home Grounds and Animals (VCE publication 456-018)
Leaf spot diseases of trees and shrubs (University of Minnesota)
Aphids (Virginia Tech Publication 444-020)
Thrips in Greenhouses (Virginia Tech Publication 444-281)
Spider Mites (Virginia Tech Publication 444-221)
Insect and Mite Pests of Boxwoods (Virginia Tech Publication ENTO-42NP)
7. Invasive plants are, of course, best handled early. Learn to recognize seedlings of common invasives like Asian bittersweet and autumn olive. And be sure not to plant an invasive! Virginia maintains a list of invasive species, many of which are unfortunately still commercially available. Virginia also keeps a list of native alternatives.
Removal methods depend on the plant. Some, like Japanese stiltgrass, are easily pulled by hand. Others, like English ivy, are much harder to remove manually. Herbicides, judiciously applied, are good tools for large-scale removal – but aren’t necessarily the best tool: many plants, like English ivy, are resistant to foliar glyphosate application. Brushing herbicide on freshly cut stumps works well for trees and shrubs like tree-of-heaven (Ailanthus altissima). Before trying that, consult the detailed guidance on control methods and cautions at Blue Ridge PRISM Factsheets–Control Methods.
Persistence is key, no matter the method. Many invasives have deep root systems and resprout after cutting. Repeated mowing or weed-whacking, which eventually exhausts the roots, might be required.
Resources:
Exotic Invasive Plants (VCE publication 420-320)
Blue Ridge Partnership for Regional Invasive Species Management (PRISM) Factsheets
Virginia Department of Conservation and Recreation Invasive Species Factsheets
6. Tree/shrub transplant and care should start by picking the right plant for the right place. Match location with sun or shade tolerance. Avoid poorly-drained soil. Test the soil to ensure proper nutrition and pH. Plan ahead: will the tree/shrub interfere with other plants, or power lines? Will it be too close to buildings?
The best time to transplant is fall, winter, or early spring, during dormancy. Transplant into a hole 3-5x the root ball’s diameter, deep enough that the top of the roots are just above ground level (for heavy/compacted soils, a little higher). Backfill and water thoroughly.
Care mainly entails pruning, fertilizing, and irrigating. Sufficient – not excessive! – irrigation is especially important in the first year or two.
Resources:
Problem-free Trees for Virginia Landscapes (VCE publication 450-237)
Planting Trees (VCE publication 426-702)
Fertilizing Trees and Shrubs (University of Maryland publication)
How to Evaluate a Tree (VCE publication SPES-313P)
5. Insect/tick ID is important because many insects are beneficial. Handle pests using suitable methods. Some ticks, like the deer tick that spreads Lyme disease, are worse than others.
The Help Desk can identify insects and ticks from physical samples (prepared according to these guidelines) and clear photos. Virginia Tech’s Insect ID Lab (idlab@vt.edu) is a great resource. Google Image Search – can be helpful; simply describe the bug – and reverse image search (click the camera icon and upload a picture).
Resources:
Insect Identification and Diagnosis Request (VCE publication 444-113)
4. Soil testing is always a good idea. Collect a representative sample by mixing sub-samples from about 10 spots. Sample boxes and submission forms are in a plastic box outside the VCE office (460 Stagecoach Rd., Charlottesville). Clients must mail samples to the lab themselves. Results will be emailed.
Test results include a soil amendment plan. Sometimes these are hard to follow – or it’s unclear what kinds of fertilizer are needed – so don’t hesitate to contact the help desk after receiving the results.
Pay particular attention to pH recommendations. Availability of many soil nutrients depends on pH. Calcium is a classic example: low pH impairs calcium uptake, so squash and tomatoes may show blossom-end rot even in calcium-rich clay soil if the pH is too low.
Resources:
Virginia Tech soil testing lab
Sample information sheet for submission
3. Tree/shrub browning or decline is a common question because there are many causes: root damage/disease, environmental stress (e.g. cold/heat/drought/salt), circulatory system (i.e. phloem/xylem) diseases, and diseases directly affecting leaves.
Outcomes also vary. Drought damage can usually be reversed, and salt damage is typically superficial. Root damage, e.g. from construction, might be survivable if it isn’t extensive and doesn’t lead to disease. Root and circulatory diseases, however, are likely fatal if untreated. Leaf spots, as discussed above, are often not serious. However, “Discula” anthracnose on dogwoods causes widespread leaf browning and eventually death.
Prevention is always better than cure. Plant disease-resistant varieties. Maintain vigor by pruning, watering, mulching, and fertilizing. Practice sanitation: remove leaf debris and prune using clean, sharp tools.
If necessary, we can send samples to Virginia Tech’s Plant Disease Clinic for diagnosis. The cost is $35. Collecting a good sample is critical! Instructions are at the bottom of this website.
Resources:
Tree Decline: What is it? (University of Missouri publication g5200)
Understanding Decline in Trees (Iowa State University publication SUL2)
Dieback and Decline of Trees (University of Tennessee publication SP686)
24 Ways to Kill a Tree (VCE publication 430-210)
2. Plant ID can usually be done electronically. Send clear pictures of as many parts of the plant as possible: leaves, bark, flowers, fruit. Also send pictures of the whole plant.
Google Image Search and reverse image search can be useful. Many websites and apps apply “artificial intelligence” to identify plants from pictures. (I have used Pl@ntNet, iNaturalist, and Flora Incognita.) Also helpful are “keys”, linked below, that use process of elimination.
Always feel free to bring samples to the office for closer examination! (Bring as many parts of the plant as possible.) Sometimes subtle differences in, for example, leaf vein patterns may be the key to identification.
Resources:
1. Boxwood browning/decline was our winner! This is a popular topic because, unfortunately, boxwoods suffer from many problems.
Boxwood blight is the most notorious – so famous, it has its own taskforce. The identifying characteristics of boxwood blight are defoliation and black streaks on stems. (Other diseases, like Volutella, Colletotrichum, and Phytophthera root rot, leave dead leaves attached.) Boxwood blight is usually fatal.
Nematodes are also common. Nematodes attack roots, causing dieback and/or leaf discoloration. Leaves remain attached. Voles and moles also damage roots, causing similar symptoms. Mites, and insects like psyllids and leafminers, damage leaves, though usually not severely.
Finally, consider abiotic issues. Boxwoods can suffer cold damage, which usually causes browning on top of the plant. Drought/heat/salt damage can harm foliage.
Resources:
Best Management Practices for Boxwood Blight in the Virginia Home Landscape (Virginia Tech publication PPWS-29NP)
Insect and Mite Pests of Boxwood (Virginia Tech publication ENTO-42NP)
Selecting Landscape Plants: Boxwoods (Virginia Tech publication 426-603)
In conclusion, we hope everyone will feel free to call the Help Desk (434-872-4583), or send us an email (albemarlevcehelpdesk@gmail.com), with questions about any horticultural topic. It’s never too early to think about next year’s landscape project or vegetable garden – or how to get the most out of the plants you’re already growing!
