Pacysandra Die Off

Asked April 4, 2020, 10:45 AM EDT

Hello, I have large beds of pachysandra that cover both front, side and back areas of my property. I've noticed considerable die off of it in some areas almost to the point of it being gone. The blight tends to be in front and side areas nearer the house, some possibly affected by leaf blowing. I've seen this in years past, especially after a rough winter, but nowhere near this degree of die off. I was very concerned about the spread, have cleaned out the dead stuff, and sprayed surrounding areas with Fung-onil, which doesn't seem to help (and may be hurting). So how do I proceed through spring? Should I cut it down and hope it comes back in a couple years (as you know, a slow grower). This would be tough for me because a lot is on a steep incline. Do I implant healthy plant material (the areas in back woods have healthy plants) within the diseased areas? Do I have to rip it all out and then transplant new, which would take me forever? Please let me know, this perfect ground cover is a major part of my landscaping plan, can be managed easily, grows on hills, and repels deer (a major plus). And now it's dying rapidly and I don't see signs yet of it regenerating. Thanks, I can send pics if you need.

Baltimore County Maryland

5 Responses

We've been getting a lot of questions about declining pachysandra.

Most recent pachysandra decline is related to weather and disease. Two summers ago we had abnormally high levels of rain. This led to a great deal of fungal disease in many old pachysandra beds. It weakened them. Here's what to do about volutella fungus: https://extension.umd.edu/hgic/topics/volutella-dieback-pachysandra-groundcover

Then, last summer, we had an extended drought. Combined with the volutella, it hit many pachysandra beds hard. You have a lot of mature trees. Usually trees have very little growing under them, because their extensive roots out-compete other plants for water. That kills plants under them.

Clean up what is in decline and follow the advice in the link above. Since mowing it on your hills would be difficult, you can use a string-trimmer to cut it back. A leaf blower blasting between plants might be handy to get the debris out.

Keep in mind that (Japanese) pachysandra is considered a non-native invasive plant, primarily when it is allowed to move into natural or park areas. There it smothers native plants that wildlife need. If yours has spread too far, now if a great chance to rein it in.

Ellen

Hi Ellen, thanks for getting back.

What's left in the damaged area is showing tiny new growth, so I probably wouldn't want to remove that at this point. I'm hoping that new shoots sprout from the roots, kind of hard to tell. I applied Fung-onil twice, fairly aggressively, and now I'm worried about that, as some areas where damage was severe are faded slightly. Did I do more damage than good?

Anyway, when I moved to this property years ago, pachysandra was everywhere and I was unaware that it was considered an invasive species. I did propagate it over the years out front as it was the perfect ground cover for my grassless wooded area - free, low maintenance and, most importantly, deer repelling. So if I was to remove any of it out back, whatever grows there would be consumed by the deer. And it is a slow grower, unlike the stilt grass, which is also taking over out back, far quicker than the pachysandra. And that grass is a pain keeping it out of my other beds, but it looks good out back because the deer don't eat that either. So bit of a quandary as it seems the invasive species are not favored (yet) by my furry friends, which guarantees their continuing success.

Thanks again.
Tim




Hello Tim,

There are several factors which could be influencing the discoloration of the Pachysandra growth. While mis-application of fungicides can cause plant damage, it may be more likely other causes are at play. Fungicides are only used as preventatives, and once a disease is inside plant tissues, fungicides are unlikely to be helpful. At worst, they will be wasted effort if the disease was not properly identified as one that product can control. Fungicides may also negatively impact beneficial soil life (like the good root-colonizing fungi) which would make the conditions more stressful for the plants in the long run. These are some of the many reasons why we rarely recommend a fungicide application for garden disease issues.

Unfortunately, monocultures (growing one plant over large areas) are prone to this kind of outbreak. Diverse plantings offer more of a safety net for pest and disease pressures (even environmental stresses) as often such problems are not going to impact all of the plants to the same degree, if at all. Plant mixes also can attract foraging predatory insects that help control pests before outbreak levels are reached. While likely not the case with your planting, it may be something to consider for the future if any patches of Pachysandra need replacing.

As you monitor your plants going forward, bear in mind that deer may indeed be starting to browse on Pachysandra, as herds with limited alternatives will feed on anything to keep from starving. We have heard of some gardens in the area seeing deer browsing on these of late, though it may still be sporadic. Plants don't really repel deer so much as keep themselves from being eaten by defensive compounds that browsers find distasteful or even poisonous. Thorns and spines are other defensive structures but these aren't always repellent to deer. (They don't seem to like Barberry spines but they will eat around rose thorns, for instance.) Concerning the Stiltgrass, one mode of spread is seeds that adhere to animal (like deer) feet as they move about the landscape. If your neighborhood permits fencing, you might consider such exclusion devices for the deer to help stem the tide of the Stiltgrass invasion.
https://extension.umd.edu/hgic/topics/japanese-stiltgrass

Miri

Hello again Ellen, Miri-

Wanted to check back about my ongoing pachysandra saga. It's been over a month since I applied Fungonil, in two applications, to the blighted, as well as surrounding areas and now I'm seeing some yellowing in both areas. But I also see new growth coming in so cautiously optimistic on that. But I'm wondering if there is some slow death, poisoning happening because of the Fungicide, or is it just a temporary situation? And I've fertilized once with Holly Tone, should I apply again after leaf out to combat the Fungonil further? Finally, would inserting new plugs from the unaffected back woods into the gnarly areas be worth the time consumption?

With everything going on in the world right now, the added stress of possibly destoying 30yr. old, large beds of (up to this point) virtually worry free ground cover is quite depressing. I do have plenty of other species on the one acre shade garden (Vinca, Loripe, Sedum, Creeping Jenny, and a silvery type Coleus) but they all need more attention than the Pach, and deer is a factor with some. So, guess I'll ride this one out and mow in the fall if it still looks like hell.

Thanks again for all your help.
Tim


The yellowing should not be related to the Fungonil unless the appllcation rate was wrong or the air temperature. You can only check the label and be assured you applied it properly. See comments above about Fungonil.

Holly Tone is a slow release fertilizer and you don't need to reapply it, probably ever.

The trouble of digging up pachysandra plugs is purely your call.

Keep in mind when assessing groundcover in woods that woods don't normally have "groundcover." Other than hay-scented fern, there is almost nothing that grows closely enough to be what humans call a groundcover. This is normal. A green forest floor is abnormal and unnatural looking. Unfortunately, non-native invasive plants take advantage of this and move in. It's amazing what they can do--they can even change the soil chemistry so native plants can't grow.

Many of us already have beds of non-natives (such as vinca and pachysandra.) As long as we control their spread, they have a place in home landscapes. However, in order to have any kind of natural areas, parks or wildlife, they need help and many homeowners are now planting more and more native plants!

Ellen