Watering your plants and hedging

The vast majority of plants that fail in the first year do so due to incorrect watering! Failure to correctly water your plants will invalidate your guarantee.

Bare-rooted plants once planted, by definition, will have their roots in direct contact with the soil and, therefore, rain will have a significant effect on their watering. However, even small whips or transplants will need occasional watering in dry weather, and larger bare-rooted hedging or trees will need more frequent supplementary watering.

Container-grown stock will need regular watering for the first two years or so until properly established. Assume that rain will not sufficiently water the plants for you – the foliage will act like an umbrella and the size of the rootball is too large for water from the surrounding soil to penetrate to the centre of the root zone (unless of course there is a drainage problem, in which case the plants are at risk due to waterlogging!). In fact, as far as watering goes, for the first year you might as well treat the plants as if they are still growing in pots and are reliant on you for their needs. Rain will have some effect of course, if the foliage is wet then the plant is not losing as much moisture through evaporation, and therefore will not need watering as often.

The moisture requirement of the plants is largely driven by evaporation from the leaves, so the faster the evaporation the more water will be needed – so a good analogy would be that if it is good weather for drying laundry your plants are drying out! It should not be necessary to water every day (unless using carefully controlled, automatic irrigation), in fact we strongly advise against it, but in extremely hot, dry, windy, sunny weather on freely-draining soils it may be necessary to water three or even four times in a week, whereas during prolonged periods of wet weather (proper rain, not just a little drizzle) it may be sensible to reduce the frequency of watering to less than once a week. However, on average, assume that watering will be necessary once or twice per week during the growing season (spring to autumn). The amount of water required for each plant will vary depending on the size of the rootball (a tree grown in a 250 litre container will of course need more than one grown in a 36 litre pot), but apply 5-9 litres (one to two gallons) for a 36 litre container and twice that for a 77-115 litre container.

There are a number of ways to aid watering, such as a sunken watering tube around the side of the rootball, using “Treegator”s (heavy duty bags holding up to 15 gallons of water, which zip around the stem of a tree and release their contents slowly over six hours), but one of the easiest and possibly most reliable is simply to make a raised “doughnut” of soil around the base of the tree or shrub to help create a reservoir which can drain slowly downwards rather than simply running away.

Remember that too much water can do as much harm as not enough! Waterlogging will effectively suffocate the roots and, if not rectified, will kill the plants.

If you are unsure whether or not to water don’t simply make a judgement based on whether or not the soil at the base of the plant looks damp; a little drizzle may dampen the soil surface but not penetrate much deeper, or the surface may look dry but the bottom of the planting hole may still be holding water (especially on clay soils). Therefore, if in doubt, push your fingers deeply into the soil and have a feel!

For rootballed stock, the general guidance is as for container-grown stock but be aware that the soil in the rootball is likely to be of a higher density than the back-fill that surrounds it in the planting hole or trench. Therefore be careful to water rootballs steadily, such as with a hosepipe on trickle rather than at full pressure, to ensure that the water soaks through them rather than flowing around them.

For container-grown and rootballed hedging the easiest, and probably most efficient method of watering would be to use soaker hose attached to an automatic timer. Attach the timer directly to the nearest outside tap, which needs to stay switched on permanently (if you are likely to need to use the tap for other things, fit a double or multi-tap connector to the tap before attaching the timer), run a length of hosepipe from the timer to the start of the run of hedging, and then lie the soaker hose on the soil surface, directly on top of the rootballs, for the full length of the new hedge. At normal tap pressure on level ground, soaker hose can water a length of hedging up to 40-50 metres long; for longer lengths or where the water pressure is diminished it may be necessary to set up more than one system. Set the timer to run either once or twice per day for the appropriate length of time, based on the output of the system, from early spring to late autumn. Be aware that evergreen hedges may also require occasional watering during mild, dry periods in winter but ensure that end caps are removed, the timer brought inside and the system drained down to prevent damage from freezing before frosts are due.

If your plants begin to look stressed then check the watering. If you are not sure if they are too wet or too dry simply dig down the side of the rootball to the base of the planting hole and check. If in doubt, if you are concerned, please contact us as soon as possible.