We have Griselinia hedging surrounding our property. However, with the recent temperatures reaching -15 degrees, I am almost sure the poor thing is in the throws of its last weeks. As it stands at the moment, all higher branches seemed to have dried out. At the very base of the shrub, the main trunk of it does seem to have some form a sap going into it. There is growth of at least five years, but we have to make a decision, try our best to save it if it's possible or remove it and replant before it's too late. Can you please give me some advice?
It might be able to be saved, but it will be iffy and if successful, it will take some time for it to achieve its former growth. It is not really a decision I can make for you. It is more of cost of new plants vs time and effort for the old plants. Most people decide to plant new rather than go through the effort. You can give it some nitrogen rich fertilizer. That will help to boost the foilage growth.
Two years ago I planted fifteen Grisilinia as a hedge. Most of them are doing very well. However, one died a year of planting. Iremoved this. A year later I note that another Grisilinia in the hedge has blackening and drooping leaves. I think it is dying. What can I do to keeep the other plants healthy. What is causing isolated Grisilinias to die? Thank you
This sounds like a specific to cultivar fungal infection. I would recommend putting dolomitic lime and wettable sulfur around each one. This will help kill off anything as long as it hasn't progressed too far. Here is an article for their care: https://www.gardeningknowhow.com/ornamental/shrubs/griselinia/growing-griselinia-shrubs.htm
I have new griselinia hedge plants put in in January/February time. some are growing great but some have died and some have brown leaves. What can I feed with to bring them along. If they have brown leaves will they survive. I have noticed some have new growth on the bottom because I cut the top off. I really don't want to loose them as it cost me a pretty penny to have a gardener put them in properly. Thanks
This article will help you.
I have heavy clay soil dries up in dry weather and water logged in heavy rainy clay soil
Our experts say, "The shrub isn’t particular about the soil type as long as it is well-drained. It tolerates a wide range of pH, from acid to alkaline, but you should avoid extremes." So, it sounds like you need to do some soil amendments and pH testing before you plant. Here's an article about how to fix your soil to accommodate your new griselinia hedge: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/how-to-improve-clay-soil.htm
After you get your soil ready and the shrubs planted, here's a helpful article about how to care for your plants. https://www.gardeningknowhow.com/ornamental/shrubs/griselinia/growing-griselinia-shrubs.htm
I know the black is frosted tips, but the brown was there before the frost, and is not on neighbouring plants of the same kind. I have trimmed away a lot of the affected branches, but not sure what else to do.
These articles should help: