Pieris Japonica all turned yellow this spring - Ask Extension
I have 6 Pieris Japonicas all of same variety. They blossomed this year with white blooms but haven't grown much in 3 years.
They started turning yel...
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Pieris Japonica all turned yellow this spring #789164
Asked May 03, 2022, 7:43 PM EDT
I have 6 Pieris Japonicas all of same variety. They blossomed this year with white blooms but haven't grown much in 3 years.
They started turning yellow last fall and I amended the soil around them and put down organic compost. They are evergreen but I don't see many green leaves.
I do see lots of little brown spots on the top of their leaves and a lot of bare branches. I don't see any insect activity under the leaves
Yamhill County Oregon
Expert Response
Hi Vivian,
Pieris need slightly acidic soil. So first thing you can do to improve their health is to manipulate the soil pH. Aim for 5.0-6.0. You may take a soil sample into the OSU Extension officefor pH testing. Presuming that the soil is too alkaline, you can purchase fertilizer which is specifically for acid loving plants like blueberries, rhododendrons, and azaleas. They might just need more fertile soil than they have.
Next, Pieris need consistently moist soil. This means that you have to be diligent about watering during summer. The past 3 summers have been hot and dry. Keep the plants well mulched to protect their roots from drying. Here's a link to a page of information about Pieris from the Missouri Botanical Garden. You should note, that they consider these plants high maintenance.
Another one of their pet peeves is wind. They don't fare well in windy spots.
Lace bugs can be a problem with Pieris as can leaf spot. It is difficult to tell from photos whether either of these is an issue with your shrubs.
Give the above suggestions a try to see if the plants turn around. If not, then taking a branch into the OSU Extension office for them to look at a physical specimen would be helpful.
Hope your shrubs turn around and start looking better.
Pieris need slightly acidic soil. So first thing you can do to improve their health is to manipulate the soil pH. Aim for 5.0-6.0. You may take a soil sample into the OSU Extension officefor pH testing. Presuming that the soil is too alkaline, you can purchase fertilizer which is specifically for acid loving plants like blueberries, rhododendrons, and azaleas. They might just need more fertile soil than they have.
Next, Pieris need consistently moist soil. This means that you have to be diligent about watering during summer. The past 3 summers have been hot and dry. Keep the plants well mulched to protect their roots from drying. Here's a link to a page of information about Pieris from the Missouri Botanical Garden. You should note, that they consider these plants high maintenance.
Another one of their pet peeves is wind. They don't fare well in windy spots.
Lace bugs can be a problem with Pieris as can leaf spot. It is difficult to tell from photos whether either of these is an issue with your shrubs.
Give the above suggestions a try to see if the plants turn around. If not, then taking a branch into the OSU Extension office for them to look at a physical specimen would be helpful.
Hope your shrubs turn around and start looking better.
