Solomon’s Seal

(Question)

I live in zone 3, Edmonton, Alberta.  For the last 3 years or so, I have experienced puckering…then some splitting on the leaves of my Solomon’s Seal.  And some have yellow veins occurring.  The problem isn’t contained to one area of the bed, it’s popped up in a few different places. The plant clump is about 8 foot by 2 to 3 forming a sort of hedge, the originals plants are old and they spread very well.  I put compost down every 2nd year or so, and they have always grown well.  Last year I put some copper and some Epsom salts watered in.  Hope you know what’s wrong and what to do.

(Answer)

The symptoms your Solomon’s Seal, Polygonatum, experienced of yellow veins, leaf puckering, and leaf splitting could be caused by many different things happening within your garden bed.

Yellowing of the leaf, chlorosis, could be from a mineral deficiency such as iron or nitrogen, an excess of phosphate interfering with the uptake of available copper and zinc, or magnesium unavailability.  This is difficult to identify unless a proper soil test is performed, so I would suggest you get this done.  It will also indicate your soil pH and this is important, as some plants have difficulty extracting certain nutrients from the soil if it is too acidic or alkaline.  Therefore, before adding any other amendments to your soil, get all the data you need, be cautious and then add only what is deficient as sometimes you can inadvertently make the problem worse, or even push a mineral’s availability up to toxic levels.

The symptom of leaf puckering, when not accompanied by the presence of insects, is usually caused by irregular watering.  A plant’s ability to grow uniformly is disrupted when it has to deal with sporadic draught.  This is because plant cells, when subject to draught, harden even when adequate moisture is later reintroduced.  These hardened cells cannot divide, expand and grow, while the other, non-draught stressed cells can.  This results in uneven growth, leaf buckle and pucker.

Some common pests of Solomon’s Seal are slugs, snails, and Solomon’s Seal sawfly and these could be the cause of the leaf damage.  This last insect, phymatocera aterrima, could very well be your main villain as it has a habit of eating elongate strips out of the leaves.  It is actually its larvae caterpillars that do the most damage.  They are greyish white with black heads and can be found on the undersides of the leaves, mostly after the plant has finished flowering.  Hand picking these little critters off is your best bet or asking at your local nursery if there is a control you can use safely in your area.

Some other thoughts to ponder – could the damage be as a result of herbicide or insecticide use, or could this be a viral infection?  Without a photograph of the symptoms, we cannot be certain.  It is also possible that there is no problem with your plant at all. Puckering and yellow veination occur naturally in some varieties of Solomon’s Seal.

In conclusion, I would advise getting a soil test done, adoption of a regular watering schedule once the plants starts growing again, continuous monitoring for insect infestation and, if you have been using herbicides or insecticides, either cease use this season, or protect Solomon’s Seal from spray drift if it is windy.  If the symptoms return, take a photograph and write to us again.