Knowledgebase

Larges areas where the grass won't grow. It's expanding! #821003

Asked February 23, 2023, 4:28 PM EST

There are two areas in our garden where the grass will not grow and the affected area is expanding. This has been getting worse over the past few years. Prior to that our grass was doing alright. In the back there is a patch which is all dirt. It's perhaps 4-5 feet in diameter (and increasing). A couple of years ago I tried planting grass in the area and it geminated and then died. In the front, next to the flagstone path we have the same problem and it has moved into the pachysandra and down to the stone wall next to the sidewalk. We do not use salt to melt ice so that is not a problem. Now the pachysandra is not looking well either. All of our neighbors' pachysandra is looking fine. The grass in the front was originally zoysia (see the photo!) but there is some fescue (?) and I think that's what's dying. I'm thinking it is a soil problem, though, rather than the kind of grass. My pachysandra, ivy and grass in the front always looked good. Now it's hideous. Can I send a sample of the soil to you? I've had "experts" come in and they've suggested different ideas or most had no ideas. One said a fungus, I see no visual evidence of that. Any thoughts appreciated. Thanks!

District of Columbia County District of Columbia

Expert Response

Unfortunately we routinely see infections in Pachysandra beds and the culprit is usually Volutella (related to, but not always identical to, the Volutella fungal disease that afflicts boxwoods). We do see several lesions on the stems in the photo that point to Volutella. As with many plant diseases, an infection's severity can depend on many factors, including weather (plus irrigation, since wetter conditions usually worsen disease spread), plant crowding and the buildup of debris around the crowns (where stems emerge from the soil), since both of the latter issues contribute to poor air circulation. Reduced airflow slows the drying time of foliage after rain, dew, or high humidity, all of which ties back into the surface moisture issue because leaf wetness allows for easier infection by the disease spores. Preventative fungicides are not recommended in this case because they are not very effective or practical to apply several times a year (as would likely be required in perpetuity).

While it may seem drastic, the simplest solution for Volutella is to trim back all affected sections of the groundcover and rake or blow-out any accumulated fallen leaves or other debris. Sanitation can go a long way towards reducing the spread of any spores that are left. Discard the trimmings and raked-out material; don't compost it because it could remain infectious. If the Pachysandra was otherwise healthy and not suffering from the next-most-common ailment, root rot, then the plants should rebound and regrow well as we move into spring. If root rot has taken hold or is at least partially responsible for the thinning and yellowing of the plants, then nothing can be done and bare areas might need to be replanted with alternatives tolerant of poorer drainage or soil compaction.

Does a water source keep either of these areas more damp? For example, does a nearby roof downspout empty near either location? If so, redirecting it may help prevent this problem from recurring. Even if this is not a new drainage pattern, our changing levels of rain over the years can be a reason behind the development of disease when nothing else has changed in the landscape. 2018 was an exceptionally wet year in our area, for instance, and sensitive plants are still succumbing to its after-effects. Is the soil more compacted in either spot from human or pet foot traffic, either cutting across that part of the yard or by stepping off the pathway? This too can tax roots to the point of dieback, both for the Pachysandra and the turf.

We presume the zoysia is what's pictured in the second photo (as it's still dormant), so is the other photo with greener grass the fescue area? The care over the course of the growing season between these two turf types will differ, which is why we ask. Plus, the green-looking grass in the first photo might actually be the weed Annual Bluegrass (we can't see enough detail in the photo to tell for sure), since this weedy grass greens-up pretty early in the season. Although Annual Bluegrass by itself is not a serious lawn weed, it can indicate soil that is too compacted and damp to allow for vigorous turfgrass.

What appears to be moss in the same photo also suggests either dampness, compaction, acidic soil, and/or part shade is a factor in the lawn's decline. If the site conditions are not ideal for turf (full sun, good drainage, near-neutral soil) then we encourage gardeners to replant the area with lawn alternatives, whether those are other types of groundcovers or different plantings entirely. If you want to keep this area as lawn for its tolerance of foot traffic or for aesthetics, then having a laboratory soil test performed might be wise before attempting to adjust the site to retry establishing lawn. We don't test samples ourselves (there's a lab list on the linked page) but can certainly help you to interpret the results if desired.

In the second photo with zoysia, we can't quite tell what the site conditions may be like since zoysia requires full sun to thrive and Pachysandra is stressed by full sun, preferring mostly shade. While it's of course possible a shadow is cast over the Pachysandra section but not the lawn, it's probably the case that the conditions there to do not suit both plants simultaneously. Either plant being stressed by its conditions could make it more vulnerable to dieback from other issues, which is why we ask. If the trouble spot between the lawn and Pachysandra continues to not support either plant's growth, perhaps using a low shrub or other accent there instead would be the best approach. We can make some suggestions if you prefer but would need more information about desired mature size (without pruning), any seasons of interest you prefer, if you think the soil skews wet or dry there, and how much summer sun it receives. Whether or not deer regularly visit the yard is also important.

Since you mention ivy (we're presuming English Ivy), we'd encourage you to remove it entirely if it's giving you a good opportunity to do so by having dieback problems as well. Both English Ivy and Japanese Pachysandra are non-native invasives, and particularly in the case of English Ivy, can colonize woodlands in natural areas. English Ivy can contract a bacterial leaf spot which causes decline, which may be what you're seeing if it's ailing. A replacement groundcover could consist of a medley of native species or just any mix of non-invasive candidates.

For any area you intend to reseed or re-sod with turf, we have a range of web pages about lawn care and maintenance that should help with the details of how and when to do certain steps, usually separated by fescue or zoysia lawn types. (Either on separate pages or discussed separately in the text when it's relevant.)

Miri
Miri,
Many thanks!! You are amazing and so very thorough. I do feel a bit overwhelmed though!! I’m not sure what to do next short of really cleaning out the area of pachysandra for a start. Can I do this now??  If I have to replant that area what do you suggest??  I’m not sure that water or poor drainage is the culprit here. This is in our front yard, away from the house and gutters and drainpipes. It’s a slope so there is natural drainage but there is no question that everything has changed in the past few years as we have had excessive rain.  This is also not an area where people or pets would trample down the soil and damage the roots. 

This is all in the front where the zoysia is. The front is shadier now than when the zoysia was planted (perhaps 50 years ago!!), however as much as I hate zoysia it does get green and that’s all I want!! 

I’m not surprised that you identify a weed in the 1st photo. That’s in the back. Drainage is definitely a problem there and I know alot of what grows is not “proper” grass. And yes! We have a lot of miss!! I should mention we had our trees seriously trimmed/ pruned 2 years ago and that helped a lot. It was, indeed too shady!  

For aesthetic reasons I really do like grass - also we have lived here for 40 some years and most likely will only be in the house another 8 years or so. hence I don’t want to invest a fortune in the lawn or lawn alternatives. I love gardening and have beautiful plants but for this lawn issue I’d like to hire someone. I had several well recommended companies come to make suggestions and give estimates a year or so ago but they varied in price and direction so much I didn’t know where to turn!! 

I like the idea of planting a small shrub where the pachysandra is dying but is the soil damaged too?? Will a shub survive in affected soil?? Suggestions for a shrub??  Not too tall, no, we don’t have a deer problem, the house is on the south side of the street so it’s relatively shady. I think I should send soil samples out to know a bit more (thanks for the list!). 

What other ground cover do you suggest as a substitute for the ivy??

How do we find landscapers/ garden companies/ turf companies who really know what they are doing??? 

Many many thanks, Miri. This has been immensely helpful!!
Ann


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On Feb 24, 2023, at 3:10 PM, Ask Extension <<personal data hidden>> wrote:


The Question Asker Replied February 26, 2023, 3:22 PM EST
Hi Ann,

You should be able to do a trim on the Pachysandra now, even though new growth is still a few weeks away yet. As for replanting either of those areas (or the Ivy) with another groundcover, there are a number of possible candidates. We encourage gardeners to use native plants for the sake of wildlife value, but non-natives are fine as long as they're not invasive. (On that front, we would discourage the use of Ajuga, Vinca minor, Creeping Jenny, and creeping Liriope spicata.) If the site is partly or mostly shaded, we've heard many folks be successful with the native perennial Golden Ragwort (Packera aurea), which spreads into a patch and has golden yellow daily-like spring blooms. It retains most of its leaves into winter. Two non-native ideas would be Barrenwort (Epimedium, which is sometimes evergreen and sometimes not) and Mondo Grass (dwarf or otherwise, both evergreen; Ophiopogon) which is are slower spreaders.

Few other native species are evergreen, but their roots and leaf debris would help protect the soil from erosion during winter. Woodland Phloxes (either Phlox stolonifera or Phlox divaricata) can contribute fragrant blooms in spring. Foamflower (Tiarella cordifolia) can spread, with some varieties running more than others, and it tends to retain some leaves into winter. For more sun, Moss Phlox (Phlox subulata), certain types of creeping Juniper (including Juniperus communis varieties for a near-native), low-growing St. Johnswort varieties (Hypericum), plus several other non-native perennials and low shrubs could work well.

Since you prefer the look of grass, though, in areas you want to re-"lawn" you might try either the Mondo Grass (despite its name, it's not a true grass) or one or more varieties of sedge (Carex). Many sedges are native here, but a handful commonly sold are not, so both groups are on the market in our area. A great resource for selecting the most appropriate (and most appealing) sedge is available from Mt Cuba, a Delaware public garden and research facility that specializes in native plants and who recently completed a trial with many types of sedge (visit the link for the results, accessible in a handy pamphlet or spreadsheet). You'll notice that a few of the evaluated sedges can even be mowed once in awhile for gardeners who like that aesthetic, though it's not something the plants require for their health. In general, sedges are an excellent grass look-alike for areas that have become too shady (or perhaps too wet or dry also) for turfgrass to thrive.

To make a replanting of either area simpler and possibly cheaper, if you went with a native species or one of the native sedges, you may be able to source plugs via mail-order (they aren't as commonly available in physical stores). Plugs are plants that are older than seedlings but not as mature as the plants sold in larger pots at most garden centers. They will be much cheaper per plant, but are usually sold in volume (say, a full tray of the same species, where the tray may hold anywhere from 30-odd to 50-odd individual plugs). This makes them more economical to plant over larger areas (if you were replacing the Pachysandra, for instance), and despite their younger age, plugs tend to fill-in reasonably quickly. As with any new plant, they'll need to be monitored closely for watering needs their first year, but are otherwise relatively low-maintenance.

If you wanted to hire a consultant or a landscaping company, you may find someone suitable through the Chesapeake Bay Landscape Professional program (use the "find a pro" link on their site), who are trained in sustainable gardening practices and who may have more familiarity with using native plants (selecting, sourcing, and installing them). We don't compile a list of area landscapers, but you can find other tips for vetting candidate companies from the Landscape Contractors Association. If you use social media, you could also solicit recommendations or feedback about landscaping companies or landscape consultants from members of local or state-wide gardening groups, especially among those that put a focus on native plants if that's the direction you want to go in.

The soil in trouble spots isn't necessarily damaged per se (at least, not when there isn't a serious contamination from something like a chemical spill or salt exposure, so it won't need replacement), but compaction can make it harder for plant roots to access the oxygen they need, and in a similar way it can negatively impact any beneficial soil microbes that would be helping plant roots stay healthy. Compaction can be reduced over time by adding organic matter to the soil (via annual topdressing with compost or biodegradable mulch after planting, or by amending with compost upon planting) and avoiding stepping on the site too often afterwards.

If the site skews wet after rain, or even dry in summer, there are perennials or small shrubs that can handle that stressor. For example, if a partly-sunny spot with occasionally damp but not soggy soil, candidates include dwarf varieties of Black Chokeberry (Aronia melanocarpa, like the 'Lo Scape' series), Lowbush Blueberry (Vaccinium angustifolium) or one of the dwarf Blueberry hybrids (Vaccinium), or even a dwarf Winterberry (Ilex verticillata), though the latter requires a pollinator somewhere else in the yard and would take up more room overall than the other two suggestions.

By itself, moss is not a problem and can be a great groundcover either used alone or with a mix of perennials, where it can be left to spread where there is room. Mainly, it's just a useful indicator of the light, moisture, and soil conditions which help it thrive. Moss won't tolerate too much shade, so if other plantings are put into that area and they spread to cover the moss, it may die out on its own.

Miri
My thanks, yet again, for your help and suggestions. The idea of plugs is very helpful. You mention  mail order. Any ideas of companies to contact or should I just google sedges/plugs?

I failed to mention that I often find grubs in the garden and “lawn”. What do you suggest about dealing with them? 

I appreciate your mention of the Chesapeake Bay Landscape Professional Program. 

What a fabulous resource you are. A million thanks!!
Ann


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On Feb 27, 2023, at 3:27 PM, Ask Extension <<personal data hidden>> wrote:


The Question Asker Replied March 14, 2023, 1:16 PM EDT
You're welcome!

Grubs in lawns can occur without causing notable damage to the turf (or to garden beds or other plantings that may replace turf), so their presence doesn't necessarily mean treatment is needed. You can compare the density of grubs observed with the information on our Identification of Grubs page, since different grub species can cause damage at different densities. When control actions are warranted due to high grub numbers, you can explore your options on our White Grub Management page.

We don't keep track of nursery suppliers or what they grow/sell, nor do we recommend particular businesses, so unfortunately you may just need to search the web or ask for source recommendations via social media gardening groups. Not many nurseries producing plugs are located in Maryland currently, but several are probably in the mid-Atlantic region at large or in southern New England and thus not too far in terms of climate compatibility.

Miri
Again I thank you for your help. Things continue to look bleak but the pachysandra is showing some growth and I am somewhat happy. Should I use any fertilizer to encourage growth? I DID cut back all the areas which were dead, dying, or unhappy.  Perhaps that helped. Should I do anything to augment the soil? 
I am wondering about something else I observed.  We have a huge (over 100 year old) Red/ Japanese Maple which rises above the ivy and pachysandra. Of course it creates shade, but another issue I am seeing is that the leaves of the ground cover are coated with a shiny accretion. It does not appear to be sticky but has that appearance. I am wondering if it is coming from the red maple. Wherever the tree overhangs, the shiny coating exists. Any idea what it is? Could it be affecting what is beneath? I have attached photos, although they don't quite reveal the surface effect.
 Many thanks, I look forward to hearing from you.  

Ann
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The Question Asker Replied April 12, 2023, 8:32 AM EDT
Hello Ann,

We suggest not using fertilizer, not only because the soil probably isn't deficient (a laboratory soil test is the only way to determine this) but because over-nourishing plants ailing from a pest or disease tends to make the situation worse. (It triggers the production of new growth the plant won't be capable of defending.) Augmenting the soil also probably isn't necessary and would be hard to do without disturbing established groundcover and tree roots. Compost is a good top-dressing for established plants (only about an inch layer atop the soil but below any mulch used) but its use may not be needed here.

The sticky or glossy residue is almost certainly honeydew, the waste product of sap-sucking insects present in the tree canopy. It could be from aphids, a common but very minor pest on many plants (including Japanese Maple), or soft scale, also relatively common and which could be present but not causing the tree too much stress. You can have a certified arborist examine the trees if you're not certain scale are present and, if they are, what treatment options make the most sense. As far as we're aware, the honeydew itself should not cause any problems for plant health below the maples, though if sooty mold grows atop it then its shading of the leaves might slow growth or cause temporary decline. (The mold itself does not infect the plants.)

Miri
Miri
As always, many thanks. 
This is extremely helpful! 
Ann

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On Apr 12, 2023, at 10:23 AM, Ask Extension <<personal data hidden>> wrote:


The Question Asker Replied April 12, 2023, 11:34 AM EDT

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