Garden Irrigation

Some obvious and some not-so-obvious observations on garden watering.

Changing Climate.
Ensuring your garden plants have sufficient water to develop properly has always been a concern for gardeners everywhere, but with our changing climate, and its tendency to get warmer and drier, garden watering has become more important than ever before. Since our arrival at Winsford in 1999, we have noticed that not only have successive summers become warmer and drier but our winters have tended to become drier.

UK tap water is second best.
In the UK normal tap water contains chemicals that very effectively sterilise it. It even contains chlorine and fluoride! Not only does tap water contain a reduced amount of the valuable trace elements so necessary to healthy plant growth, but I also believe this sterilisation tends to 'burn' the fine microscopic root hairs of all plants so necessary for them to absorb all nutrients in the soil.

As a result, there is nowadays a very clear difference for all gardeners between watering with 'commercial utility water' and a good downpour from mother nature.

Rainwater storage.
Winsford is most fortunate for the forethought of the original Victorians who built the garden. There is a whole series of water tanks which once collected all the winter rain from the thirteen greenhouses. The water collected could also be used to effectively quell any house fires. Though this seems like a risky prospect, containing hundreds of gallons of rainwater in a suburban area was seen as an effective use of space at the time. Predictably, the practice was well thought-out - imagine how low the quote from Aviva would be if you had an industrial quantity of fire-fighting material? Nowadays, copious rainwater is collected from the rooves of our home, exhibition and restored greenhouses. Collecting rainwater is only half the problem and the easy half at that. Distributing the water to the plants that need it, when they need it and without wasting this precious resource is much more difficult.

Plant needs first!
Using a garden hose has obvious advantages and most people use a 12mm or 1/2" hose. At the end of a 50m run of hose, the pressure is noticeably reduced and it will take a couple of minutes to fill a two gallon watering can. On that basis if your new shrub is going to receive a minimum of four gallons you will need to water each plant for4 minutes. Just ten plants will take 40 minutes. Most people don't have the time to water properly in this manner. Hence the need for proper irrigation.

Did you know that a 50m 22mm hose or 3/4" hose will fill a two gallon watering can in about 25 seconds? That extra 1/4" makes a terrific difference on the volume of water delivered. Those same ten garden plants can have same volume of water not in 40 minutes, but in 4 minutes tens seconds! Do you still want to go out and get that standard 1/2" hose? Of course, the flip side of all this is that if you become 'distracted' when the hose is on!

Best time to water
The best time to water your garden is in the evening as this allows your plants the maximum time to enjoy their refreshment before the next days' blast of sunshine. Watering in the evening also gives your plants time to enjoy the extra moisture on their foliage which would otherwise quickly evaporate.

If you do not have garden sprinklers and must stand with the hose which, sad as it may seem, is my prefered method because I actually enjoy it as a means to wind down and properly assess my plants at the end of a series of successive hot days. With a 3/4 hose I can put a deluge around the base of a large thirsty shrub in about 30-60 seconds, whereas a sprinkler would take several hours to do the same and waste a lot of water in the process.

The worst thing that you can do in the summer is to go out and water with a milk bottle for each. (I've seen it done!) Under-watering does not reach the deeper roots and does more damage than good as it tends to draw the roots back to the surface, where they are more likely to die in summer and freeze in winter. If, for whatever reason, you don't have time to water all your plants, it is far better to water fewer plants but water them well.

Plastic push-fit hose fittings?
These are everywhere, particularly the push-fit systems from Hosefit and Gardena. But plastic fittings crack and leak and must be replaced, and quality brass fittings have come down in price so much that there is almost no difference between plastic and brass in some retail outlets. However, the biggest disadvantage with any push-fit fittings is that they can very easily blow-off. Everyone has suffered at least a wet shirt at some time or another.

Geka hose fittings
For little more than the cost of common plastic alternatives the very best method of connecting garden hoses is the brass geka coupling (pictured right). Their superior design ensures there is no danger of a connection blow-off. Fittings simply push together and then the all-important quarter twist secures. Once a hose is properly secured to the long shank of the brass Geka couplings using a Jubilee clip your days of burst connections are history. Pictured right is one of the take-offs located around Winsford walled garden which enable me to use shorter hose lengths, which are 'plugged in' to the permanent 40mm circuit wherever required.

Fixed water circuit at Winsford
After one summer of hauling heavy 50m long hoses around the garden I made sure that a new fixed pipe work was installed during the very next winter. As a result there is now a permanent 40mm pipe hard plastic pipe from the largest water tank with a series of geka fittings along its length. The pipe acts just like the ring main in your kitchen, enabling shorter, more convenient lengths of 20mm (3/4") hose to be added just like when you connect appliances wherever you need in the kitchen. The great benefit of 40mm pipe is that it can supply such a volume of water that several draw-offs can be used simultaneously.

After a blazing summer in 2006 a similar, shorter 32mm pipe circuit is planned for the plant sales area in the East Garden during 2007.

And a final word on water storage
Throughout the hot summer of 2006 visitors marvelled at the sheer exuberance of the plants despite our drought (which lasted 13 weeks at Winsford), and I considered converting one of the underground boiler houses to a large cistern during the following winter. It would need some minor brickwork to seal the stairwell, and entail a simple timber/acrylic roof to keep out falling leaves, plus a power supply, submersible pump and pipework. Not a big job by any means. Unfortunately, the butyl liner alone worked out far more expensive than it would cost to fill the cistern with tap water for at least ten years consecutive years! So that idea was put on 'hold'.