What a winter! Plant losses and what to do about it.

This year has been extraordinary. We have many clients who have reported plant losses, and whilst a few do tend to go over winter, it is usually just the odd one, not whole rafts of plants that normally over-winter happily. New stock is always more susceptible to winter loss as it does take plants a few years to get fully established and they are at higher risk if the winter is bad.

Looking more broadly, there have been reports of a higher than usual number of plant deaths this year across the UK from gardeners and suppliers. There are several factors that may have contributed to this phenomenon.

Why do plants suffer over winter?

• Typically it is getting waterlogged, frosted or drying out. This year has largely been a combination of the first 2. Plants have different tolerances for cold temperatures. Some plants, like many evergreens and conifers, are adapted to survive the winter and will typically continue to thrive despite the cold. Other plants, however, are not as hardy and may struggle or die if exposed to harsh winter conditions. Whilst this winter has not (on average) been colder than many others, it is the timing of the cold snaps that have hit the plants hard. Milder weather encourages the plants to break dormancy early, even put new buds and shoots out, and if a frost hits those tender shoots, it causes them to freeze, rupturing the cells and causing irreversible damage. This may cause the whole plant to die, or just result in die back of existing leaves and some branches.

• Extended wet weather makes everything worse, causing hard freezing around waterlogged plant roots, and the plants are likely to have already been under stress as few species like to sit in water for long periods.

• Snow sitting on evergreen plants causes die back in the leaves (Portugal Laurel in particular seems to have suffered with that this year)

• Just to prove that you can’t win with gardens sometimes, in other years, one of the main reasons that plants die over winter is due to a lack of water. During the winter, plants go into a state of dormancy and don’t require as much water as they do during the growing season. However, if there isn’t enough rainfall or snow to keep the soil moist, the plants may become dehydrated and die.

• There can also be the normal problems with pests and diseases, with a hard winter making foraging animals more problematic as they go further and further to get food, and eat things they normally would not touch.

How do I reduce the chance of winter losses next year?

So, what can you do to prevent your garden plants from dying over winter? Here are a few tips:

• Choose plants that are appropriate for your climate. Make sure you’re selecting plants that are hardy enough to survive the winter temperatures in your area. If they are not fully hardy, take steps to protect them. Tree ferns, Olives, Acacia trees and Palms in particular have largely been fully hardy in the South of England (especially London) for years, but many people have lost those in the last few years.

• Do a good mulch before winter hits- spreading 5cm of a good organic compost around the plants after they have been tidied for the winter not only makes the beds look better, it keeps the moisture in and the ground temperature a little higher as well as providing some protection from smaller critters looking for food

• Keep an eye out on the garden in winter- don’t just leave it entirely. Remove snow from plants that you can do this to- shake branches on shrubs bent over in snow before they break, and sweep snow from the tops of clipped hedging if possible. Keep an eye out for animal damage, and do assume you will have to water as soon as the weather dries in Spring if there is no rain

Now I have lost a lot of plants and my garden looks bare what do I do?

Gardens do tend to look a little bare at this time of year, and many plants that look as if they have died may yet surprise you. Looking at local gardens I note that Pittosporums and Hebes have suffered in a way that I have not seen before. Hydrangea ‘little lime’ has also been hard hit, but some of these are now putting on new growth and coming back. I suggest leaving it another few weeks before pulling out the dead plants unless they have definitely gone.  Once the plants start to grow back it is always a bit surprising how much ground they cover.

Once you know what you have lost, take stock and perhaps spread plants that are doing well or aim for a top up. In more normal years I would not recommend replacing like for like as you risk losing them again, but I think I would judiciously replace those that “should have” survived with the same again as long as it is not a huge investment. Balance that with some hardier varieties and a general stock take of the shape of the garden. Perhaps this gives you an opportunity to perk up beds that were overdue a reshuffle, and since it tends to be multiples of a single variety of plant that have gone, you can shift the colours or seasonal interest a bit.

If you need any help to review what has gone, and advice as to what to replant or how to give your planting an overhaul do feel free to get in touch.

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