Thursday, March 15, 2012

Giant leaves and hosepipe bans. An impossible combo?

During the past week there have been gloomy announcements about the state of the UK's water supply. Or more specifically, the East and South East's water supply. We are in drought! A particularly dry spell has not re-filled our reservoirs or ground water supplies and a number of rivers are running at reduced capacity. 

The result? Hosepipe bans coming into force on the 5th April for much of the South East, with threats of more areas to follow later in the year. You can read the bbc's report on this news here.

As much as I think that Boris Johnson is a bit of a wally, I couldn't help but quote him on this: 'The rain it raineth on the just and the unjust, says the Bible, but frankly it raineth a lot more in Scotland and Wales than it doth in England'. He has a point. Scotland, Wales and the West is wetter than the East. But that has always been the case. Is it just me that wonders whether the massively densely populated SE corner is extracting far more water from its finite resources than is sustainable in the long term? Or what about the state of our crumbling and leaky pipes? Perhaps it is safer to leave that train of thought there before I get carried away in a bit of a rant.

Here in Devon (in the South West) we are lucky. The regular Atlantic fronts that sweep in from the sea bring enough rainfall to keep us from hosepipe bans and such annoyances. At least they have so far!

So anyway, what does all this mean for those of us who grow big leaved plants? How can exotic gardeners possibly hope to create their own version of a Borneo rainforest when water is scarce and limited? What about the Ensete ventricosum? The Musa basjoo? The Tetrapanax 'Rex'?! Plants with leaves of this size are thirsty!

Musa sikkimensis - this much foliage is going to use a lot of water!

Is is feasable to grow large stands of Musa basjoo during a drought?
I've spent a few moments thinking of a few solutions:

There are the obvious suggestions, like installing a water butt. Or if you already have one, adding a second or a third! Not that this will make watering the garden any quicker, but is does save water, so it can only be a good thing.

How about saving dishwater or bathwater for watering the garden? Using so called 'grey water' is common practice in many parts of the world, so there is no reason why we can't do the same here. I'm sure we can all be a little more resourceful with the water we use if we put our mind to it.

Another thirsty plant that does best with regular watering - Tetrapanax papyrifer 'Rex'

How about adding a mulch of bark chippings or composted woodchip to your borders? This has the benefits of conserving ground moisture, and will eventually rot down and nourish the soil over a period of years. Laying the mulch on ground that is already wet after rainfall is really important! That way, the moisture that is already present is conserved. Research has shown that keeping a thick mulch can conserve water deep down in the soil. Plants with shallow root systems or that lack deep taproots, such as bananas for example, will really benefit from this treatment.

Tree surgeons often have shredded chippings that they are only too glad to get rid of, and this can be a cheap source of mulch. However, a word of caution here - only spread woodchip that is old and part rotted, rather than fresh. The fresh stuff will start to rot down on the beds and use up valuable nitrogen, leaving less available for your plants.

Improving the soil structure can help conserve water. Horse manure or well rotted compost is generally pretty water retentive as well as being full of nutrients. Try working lots of this into your soil. I have recently seen a photo of an Ensete ventricosum grown in pure horse manure and the results were very impressive!

If you plan to plant up tubs or pots of annuals, or even grow large leaved exotics such as colocasia in tubs for the summer, how about using water retentive gel in your compost mix. This stuff is widely used by bedding plant growers to make watering more efficient. Obviously, only plant actively growing colocasia in this, and not dormant or just 'waking up' corms if you want to avoid them rotting!

If you really crave plants with that 'wow' factor, and don't want to risk putting up with stunted bananas and dried Tetrapanax, then maybe the xerophytic route is the option for you? This style of garden uses drought tolerant plants, including cacti, succulents and yuccas amongst others. A sunny, south facing site with extremely free draining soil is essential for long term success, along with careful plant selection. This is a style that has been largely pioneered and developed in the UK by a well known exotic gardener, Paul Spracklin. Will Giles has created a xerophytic garden at The Exotic Garden in Norfolk.

Well done if you've read down this far. You just have one final suggestion to go - buy a bigger watering can!

What other ideas has anyone come up? It would be interesting to hear your suggestions.


  1. Yes I've read it all the way down! Entertaining and thought provoking post. There are are many ways indeed to cope with the hosepipe ban, after all we've been through this before (a few summers ago). We'll need to buy more watering cans too!

  2. Hi Mark and Gaz, interesting - did you find that a hosepipe ban negatively impacted your garden at all last time round?

  3. Is there a real problem for dedicated gardeners?
    As far as I know you can use drip irrigation attached to a timer although no one actually says how long the timer can be on. Leaky hose is cheap, easy to lay, and can be hidden under a layer of bark chips if you not inclined to sink it into the soil.

  4. Hi Don, that's a good point. I hadn't considered that idea, obvious though it now seems! I guess it would be a good idea to check with your local water authority whether soaker hoses or drip irrigation are still allowed.

    I think you've summed it up well your comment about dedicated gardeners. A dedicated gardener would get the watering done regardless, even if it means 100 trips with the watering can!

  5. Interestingly, according to Landscape Juice (an interactive network of landscapers and garden designers) the hosepipe ban is likely to spell disaster to many landscaping businesses, as new plantings and turf etc cannot be properly watered after April 5th. Here is how they describe it:

    'There looms a crisis for the landscape and horticulture industry that is potentially more devastating than the credit crunch and the big freeze put together.'

    I'm glad to be based in the wetter west!