For those still waiting for water levels to fully subside, the ‘better’ weather of the last few weeks can be little consolation but those who have seen the waters come and go without actually flooding their home will be assessing possible damage to the garden and thinking about bringing it back to normal.
The first question has to be: “what kind of flood water”…
• Excessive rain without flooding
• Moving flood waters from a river etc.
• Static flood waters from a river etc.
• Flood waters that have brought up sewage from the drainage system
As the last of these is also a risk to human health, specialist advice must be sought to determine whether or not it is safe for you to resume gardening. As disgusting as it may be, the fact remains that gardens are far less fussy about the source of its fertilizer than we are, but do take care and check.
Moving up the list, the dislike of most hedging plants of having their feet wet for prolonged periods is well recorded, here and elsewhere, and only time will tell if your hedge or lavenders have succumbed. Plants that have been submerged for less than a week may well recover – but don’t rush to judgment and assume the worse before nature has had time to respond. On an established hedge it will be some weeks before the consequences of rotted (and therefore dead) roots work their way up to the foliage. On younger hedging plants, you will probably already be able to see whether or not they have survived.
If you have had moving water coming across your garden, plants may not have drowned, but the waters will almost certainly have taken a fair proportion of your topsoil; with it and hedges and specimen plants will need to be top-dressed with at least a good mulch.
Depending upon the location and orientation of your garden, it is possible that the rains on their own may have had a lesser, but similar, impact, leaving plants in need of a little extra TLC.
Finally, plants growing in containers. If they have been submerged or standing in water for a period, you will have to play the waiting game to see how they have fared. Also, the potential effect of the rain or flood waters on the nutrient levels of the soil needs to be considered. At the nursery, we use a temperature sensitive fertilizer in our containers, so the additional rain will not have leached the nutrients away, but as container plants in a domestic setting are not generally fed during winter, now’s the time to top-dress and add a standard dose of slow-release fertilizer. One last thing concerning container plants: don’t let the fact they’ve had excessive watering in the recent past distract you from keeping an eye on them – we’re at the start of the growing season and if there’s no rain for a few days, they may well need watering!
A couple of tips:
• Don’t walk on a waterlogged garden until all the water has drained away
• To drain a waterlogged lawn or area of earth, wait until some of the water has dissipated and the lawn/ground is visible. Use boards to walk on and spike the grass/ground with a garden fork at regular intervals. The holes should be visible, as deep as possible and (on a lawn) can be top dressed with horticultural sand