Nine ways to protect your plants in wet weather
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As more rain is forecast, Hannah Stephenson asks garden expert Jonathan Webster how to protect plans from drowning and waterlogging
Winter flooding seems to be a regular occurrence these days, with milder, wetter winters becoming the norm, which can lead to puddled lawns, drowning plants and waterlogged beds and borders.
So, with the Met Office forecasting a wet January and February, how can we protect our plants from becoming a soggy mass?
“You won’t find whether deciduous plants have been affected until spring, when they normally burst into life. The roots of dormant plants may still die off if they become waterlogged over the winter,” says Jonathan Webster, curator at RHS Garden Rosemoor in Devon.
“If the roots of evergreens start to die, the leaves may go brown, because drowning plants display the same symptoms as those which are starved of water, as the waterlogged roots are unable to supply water to the leaves.”
Keen to protect your plants from drowning and minimise the risk of waterlogging? Webster shares the following top tips…
1. Clear out your gutters
Clear blocked drains and gutters of leaves and debris. This will ensure water isn’t flooding towards your borders and is being drained off to the right place.
2. Avoid walking on grass
Try to avoid walking on wet soil or soaking grass, which will become compacted (especially with heavy clay soil) if you start treading on it during prolonged wet weather.
If you have to walk in wet areas of your garden, lay down planks or boards. If you’re tending to beds, try to remain on pathways to do your work. Incorporate organic matter to increase the oxygen content and aid drainage.
3. Add mulch
Add a mulch or leaf litter, which will help minimise soil compaction on the surface, which may be caused by torrential rain. A permeable mulch, which allows water to permeate down through the soil, can help. If you have a claggy soil, try to dig in compost in the early autumn before the winter rain comes.
4. Choose the right plant for your soil
Plants which thrive in a heavy, wet soil – such as dogwoods and willows – are more likely to survive, as are bulbs such as camassias, which love a wetter soil. Tulips, on the other hand, are more likely to suffer in persistently wet conditions.
5. Position your plants in the right way
If you have a heavy soil, pierce the sides and the bottom of the planting hole when you plant, adding crocks and gravel at the base to help moisture seep through. Avoid smearing the sides of planting holes on heavy soils – use a fork for digging and break down the sides.
You may want to try ‘mound planting’, where half the rootball is sticking out of the soil, which is mounded up. If you have a high water table, that takes the rootball out of the danger zone.
However, remember that during the hotter, drier spells you will need to look after it and make sure it doesn’t dry out. You won’t need to replant it deeper come summer, as the mound planting remains in its permanent position. This planting method is good for rhododendrons, which don’t like sitting in wet soil.
6. Create raised beds
If you live in an area with a high water table, having raised beds can help your plants avoid the wettest area.
7. Cover plants
You can cover plants to a certain extent, as long as there’s still plenty of air circulation. Popular methods include throwing a cover over an area framed with bamboo stakes, attaching the cover to the stakes but allowing oxygen to circulate underneath the cover around the plants.
Plants such as agaves, grown in pots, could be brought closer to the house to shelter them from winter rains. Make sure vulnerable container plants are placed on feet and preferably make new plantings in permeable pots which can breathe, such as terracotta.
8. Replant vulnerable container plants
Upturn waterlogged plants in pots. Remove the parts of the root system that are affected and replant into fresh compost. A smaller pot may be required due to the reduced root mass. Over time, compost in a pot degrades and loses its structure, so repotting in new compost should help reinvigorate the plant.
9. Help land drainage
Use more permeable hard surfaces to make more water go to ground, rather than run off. Bound resin gravels, which are totally permeable, are becoming more popular. And if you can capture water in a pond, water butt or on a green roof, that will delay run-off.
Few plants will tolerate extended periods of waterlogged or flooded conditions, according to the RHS, but the following trees may be grown in soils that are permanently moist: Alder (Alnus cordata, A. glutinosa, A. incana), birch (Betula pendula), Amelanchier lamarckii, poplar, pear, willow, elder and rowan or mountain ash.