Pieris Japonica Looking pale and sickly

Does anyone have a suggestion on how to proceed?

I have a hedge of about 12 pieris japonica (Purity) in a small-walled garden that are a very pale, yellowish green this spring. The leaves are dull, not glossy, and there are very few blooms. They are pretty pathetic looking., but pieris just outside garden is doing great. Could this be an acid problem -- I also have 2 rhododendron in the garden that are yellowish and I plan to try iron and hollytone. Any thoughts about whether this would help with the Pieris? I really don't want to have to replace this whole batch.

thanks much!

My thoughts are that they are related. Pieris are Ericaceous Family plants, same as rhodies and azaleas. Usually Pieris is a bit more forgiving than the others, but they still need acidic soil and good availability to iron and magnesium. I'd try a little of the iron and a regular dose of the HollyTone.

Scott

Thanks for the reinforcement -- I will go ahead and try the iron treatment and the hollytone and give it a week to see if they improve.

I will let you know if it works.

I'd recommend sprinkling a light layer of peat moss over the soil for the full length of the hedge and maybe add some slow release fertilizer.

HollyTone, being an organic fertilizer, is slow release, and it drops the soil pH some. It is generally not recommended to use peat as a mulch (or as an "on top" amendment) because it tends to dry easily and blow away. If it doesn't blow away, once dry, it is next to impossible to re-wet, and in its dry form it shells and then repells water.

However, peat is an excellent way to lower pH over a longer period of time than almost any other amendment. The best way I have found to add it is to buy it by the bale. Put the bale near where you are going to use it. Poke a small hole in the plastic, insert the nozzle of your garden hose and turn the hose on to a moderately slow flow. Allow the bale to swell until you think it will explode. Turn off the water. Go inside. Enjoy your life. Go to bed. Wake up the next morning. Go to work. Come home, and by about that time the peat will be good and wet. Now, spread two or three inches on top of your bed and gently work it in, being careful not to disturb the often shallow and fine roots of your Ericaceous plants. Cover with finely shredded pine bark mulch or pine needles. If you're fortunate enough to be amending a new bed without any plants in it yet, you can add up to five inches and till very thoroughly. Be sure it is well dispersed within your natural soil and little, if any, remains on the surface.

Another way to lower soil pH which is easier and cheaper is to add granulated sulfur every year. You can buy it in garden stores or (even better) at feed stores or agricultural supply centers. Just scatter the sulfur on top and rake it in if you want to. Rainwater slowly converts it into a mild sulfuric acid solution, which works its way throughout the soil. Instructions for proper amounts are always on the bags.

Scott