Hello Andrea,

Crown rots and root rots are widespread and caused by an array of different fungi, but the symptoms on the Ajuga look like Southern Blight, a common disease which can wipe-out patches of a dense groundcover because of the reduced air circulation around the stems. You can inspect the bases of the plants near the soil line to look for signs of fungal sclerotia and mycelium, as pictured/described on the linked page. If not found, this might be Web Blight instead, which is caused by a different but equally-common fungus. No treatment is possible for either at this point, but you should remove all dead growth and, if applicable, lessen the amount of mulch used in that area since it can increase the risk of recurrence.

Not all groundcovers contract or succumb to these diseases (though we don't have a list of resistant species), but if replanting the area, we suggest using a medley of different species so their susceptibility to future issues won't be equal. Ajuga is non-native and can be invasive in Maryland, so a different groundcover would be preferable. Wild violets (Viola sororia and many others), for instance, doesn't seem very vulnerable to blight diebacks like this, and is native and supports pollinators and fritillary butterfly caterpillars.

Southern Blight and many of the other "blight" fungi can infect several kinds of vegetables as well, but the symptoms of fungal growth and spores looks the same. More likely ailments on tomato include Early Blight, Septoria Leaf Spot, and Fusarium Wilt. "Blight" is a catch-all term for a fast- or extensively-killing infection, so one blight doesn't necessarily relate to another. That said, many fungal and bacterial infections take advantage of plants under stress, plant injuries, and the right weather conditions, which usually involves damp plant surfaces from rain, dew, irrigation, or very high humidity. (In general, wet leaf surfaces are easier for spores to infect.) These shared preferences means that different blights can cause problems on different plants around the same time. You can check out our Growing Tomatoes page for other possibilities.

Vegetables and other plants grown in containers can be more easily stressed by heat, fluctuations in soil moisture and nutrient levels, limited space for their roots, and other environmental conditions. It's difficult to diagnose the tomatoes at this point in their decline, but several ailments may have overlapped by now with symptoms that are hard to distinguish. The purplish tinge to some of the leaves suggests a nutrient deficiency issue, though weather this lies with the soil itself or with struggling roots we cannot tell. Depending on if or how the plant was fertilized, it is probably the soil that needed supplementation. In general, choosing tomato varieties with the best disease resistance (though none are immune to all of them) and growing them in the ground, where feasible, are the best way to reduce the risk of significant plant stress or dieback. When containers are the only or preferred option, make sure each plant is in a minimum container size of 5 gallons. (These appear to be large enough, but it's hard to tell if they're 7, 10, or 15 gallons.)

If you're wary of the soil in those pots, you can discard it at the end of the season and start fresh with new potting mix next year, cleaning the container out of soil residue in between. Fungal spores can always blow back into an area in future years, though, so this measure of sanitation helps but isn't foolproof. The soil around the Ajuga can be scraped off (just the surface couple of inches) or forked into the soil to "till" it under to remove or suppress any Southern Blight spores present, but this too is not a foolproof measure. Even so, no fungicide is recommended because they will not be practical or effective to apply; plus, they are preventative measures only, not curative, and by the time symptoms manifest, it's too late to treat. For the tomatoes, harvest what fruit you can as it begins to color-up (brining them inside to finish ripening) and dispose of the plant itself when they don't appear to be producing much more of a crop. If you haven't fertilized in a while, you can try giving the plants a dose (follow package instructions for potted plants), but this might not result in much more growth or fruiting.

Miri

Hi Miri, 

Thank you for your thorough answer to my question concerning my Ajuga and tomato plants. I've been meaning to thank you with follow up questions, but hadn't had a chance until now. I apologize for not thanking you sooner. My follow up question was going to be about a tree that was planted in the same location as the Ajuga. It was a Redbud tree that I think had Verticillium Wilt, and I removed it  year ago. I was wondering if whatever affected the tree could have been related to the other plants dying off. I was never certain that it was Verticillium Wilt either.

But now I have a new concern. I have another tree growing on the other side of my fence, about 5 feet from where the Redbud was. This tree (a Japanese Tree Lilac) appears to be suffering possibly from Verticillium Wilt also. As you can hopefully see in "Trees01"

Please let me know if I should start a new ticket/inquiry for this new question.

Thanks again!

Andrea 

You're welcome.

The loss of the Redbud might have been unrelated to the damage to the Ajuga; it's hard to say, especially after one or more of the plants involved are already dead. (Symptoms are more diagnostic while they are actively causing damage but less so after those tissues have died.) The photo of the dead/dying main stem on the Redbud before removal suggests something affected its vascular system (the tissues transporting water and nutrients into the canopy), but Verticillium Wilt isn't the only possibility, despite wilt being a prominent initial symptom.

Since environmental conditions that stress plants (like drought or overly-wet soil) often precede problems with insect or disease outbreaks, perhaps something happened to cause both the Ajuga and Redbud stress. Ajuga is so vigorous and potentially weedy that it's fairly adaptable, but could still succumb to root or crown rot, or blights like Southern Blight or Web Blight in soils that are too wet. Redbud isn't very tolerant of soggy soil, and it can also contract Botryosphaeria, a fungal canker disease, when stressed by drought. Any of the various pathogens that kill, damage, or block the water-conducting tissues in the wood can cause near-identical foliage symptoms of discoloration, "burning," wilting and premature shedding. Wood-boring insects, also often targeting stressed trees preferentially, will have similar impacts as they chew into sapwood (just under the bark) or those inner tissues supplying moisture to the canopy.

Japanese Tree Lilac, while not grown as widely as Common/French Lilac shrubs, can still contract comparably aesthetically disfiguring leaf spot diseases. Although we can't see them very clearly, the spots on the foliage of the pictured tree suggests this has occurred, but you don't need to spray for it since fungicide treatments don't always work (and can be expensive and a hassle to apply multiple times each growing season). You can rake-up any fallen lilac leaves and dispose of them, though this isn't a foolproof way of preventing re-infection in a future year. Growing seasons with periods of wetter-than-average weather can increase the incidence of disease, since often wet leaf surfaces are more vulnerable to infection, so it's possible the infection will subside on its own in a future year with drier weather during the window of spore dispersal.

For now, just keep periodically monitoring the trees for watering needs, and water the root zone thoroughly when the soil is become somewhat dry to the touch about six inches deep. This weekend's projected rains should be plenty for a little while, but we have had dry spells in autumn in years past that have caused plant damage later the next growing season, so it's good to keep monitoring until the ground starts to freeze.

Miri

Thanks again, Miri. You are really quick! I just want to make sure you had noticed the pale colored bands around the trunk/branches of the tree. I'm attaching a few more images so you can see what I mean. The other Tree Lilac (the healthy one) does not have this banding at all.

Andrea

Hi Miri, 

Thank you for your thorough answer to my question concerning my Ajuga and tomato plants. I've been meaning to thank you with follow up questions, but hadn't had a chance until now. I apologize for not thanking you sooner. My follow up question was going to be about a tree that was planted in the same location as the Ajuga. It was a Redbud tree that I think had Verticillium Wilt, and I removed it  year ago. I was wondering if whatever affected the tree could have been related to the other plants dying off. I was never certain that it was Verticillium Wilt either.

But now I have a new concern. I have another tree growing on the other side of my fence, about 5 feet from where the Redbud was. This tree (a Japanese Tree Lilac) appears to be suffering possibly from Verticillium Wilt also. As you can hopefully see in "Trees01"

Please let me know if I should start a new ticket/inquiry for this new question.

Thanks again!

Andrea 

Yes, the banding is interesting but not likely an indicator of a problem. Lichen growth (which is harmless) can sometimes be nearly two-dimensionally flat like that, though probably wouldn't be so linear. It may just be a normal feature of the bark, especially if these happen to be different cultivars (several types of Japanese Tree Lilac are sold although they look nearly identical). It superficially resembles Smooth Patch on oak, though we don't know if lilac is affected by that or a similar organism. In either case, the vertical fissure lower on the trunk that looks like older, mostly-sealed damage would generally be of more concern, even though there is nothing that can be done about it at this point.

You'll have to wait and see if the tree leafs-out normally next spring and doesn't drop its foliage prematurely for any reason. If symptoms of dieback manifest next spring or summer, feel free to send more photos for assessment.

Miri

Thanks again, Miri! I really appreciate your time and all of this great information! I will hope for the best. Luckily we are getting the rain!

The use of free mulch and woodchips provided by your municipality should be just fine, as most pathogens do not survive the chipping/shredding process.


Christine

Okay, great. Thanks Christine!

Hello!

I'm hoping you're able to see the thread of emails dating back to my first inquiry on 8/13/22, because they are all related. I have an area in my front yard where plants & trees are sick and dying off. So far I have lost a Redbud tree (pictured in an earlier thread), a large patch of Ajuga ground cover, a few healthy perennials/Salvia (planted last summer), a Japanese tree Lilac that is struggling on the other side of the fence, in addition to the boxwood shrubs that appear to be stunted/not growing as large as the ones further away from the problem area.

While I don't claim to know if they are all related, I do have a suspicion/concern. About 15 years ago, I had to dig up the front yard down about 12 feet, near the problem area, due to a leaking/broken sewer line. The repair was made and the area was filled back in. The sewer line was only repaired up to a certain point, pretty much right before the spot where the plants are dying. I'm wondering if the original/un-replaced sewer line could be leaking into the earth and contaminating the plants. Is there a soil test that tests for sewage leakage?

Thanks, Andrea

Hi Andrea,

Yes, we can still see the prior question history for this submission, and we reviewed the situation to refresh our memory. While sewage leak contamination in terms of a microbe problem is not likely a factor, the added moisture from a consistent leak might be a contributing factor, though we doubt a leak that far under the surface would be resulting in symptoms this varied and inconsistent. (Twelve feet under a perennial, shrub, and young tree is quite far down.) A nutrient overload can "burn" plant roots just as if they were over-fertilized, but the symptoms that have manifested so far do not point to that, and again, it would be occurring so far under the primary root zone of these plants that it's likely a non-issue even if a minor or moderate leak is present. We are not aware of testing options as this is not something a standard laboratory soil test can screen for, but you could inquire with your local health department to see if they have recommendations for determining if a leak is suspect.

Could the ornamental pond in the photo be leaking slowly, perhaps from a puncture in its liner? Does it need regular topping-off that might not be accounted-for by evaporation alone? It looks like the pond is slightly uphill from the zone of struggling plants, so if there is a leak, the direction it would travel is plausibly right into that problem spot.

We can't see much detail in the images regarding the boxwoods, but they look fairly normal; many cultivars grow slowly and if a root stressor was causing them enough trouble they'd probably have branch dieback instead of just being slower than their neighbors. Boxwoods have comparatively shallow roots and are vulnerable to an array of pests, diseases, and environmental stress factors so can be a "canary in the coal mine" for several problems, like soil that's too compacted and wet. Avoid worsening their vulnerabilities by not over-pruning them, as dense foliage that results from regular pruning worsens air circulation within its branches, increasing the odds of infection or pest outbreaks. Perhaps the stunted-looking individual boxwood that's closer to several pathway stones is struggling from more soil compaction in that area given what we assume is a greater degree of regular foot traffic there.

We suspect not given the groundcover plantings, but is there landscape fabric used under the mulch in this garden? If so, it might be affecting how easily perennial and shrub roots can access oxygen and moisture from the soil surface.

When you've dug into the site where the redbud was lost and removed, was the soil more gray-brown than red- or yellow-brown, assuming the base soil type is clay? Grayer soil can indicate low oxygen levels, whether due to more consistent wetness or soil compaction (or both).

It still could be a coincidence between the different plants succumbing to different kinds of dieback in this general area. If anything, it does suggest an abiotic issue (that is, one that is not due to a living organism like a pest or disease) that is stressing roots. Unfortunately, it's challenging to figure out what that exact issue may be.

Miri