Watering Plants under Cloches

Rain which falls on cloches it trickles down the glass and into the soil just outside. When moisture enters the soil it moves principally downwards, but also sideways, the degree of lateral movement depending on the nature of the soil and particularly on its humus content. Plants’ roots similarly grow not only downwards but also sideways, so that crops grown under cloches can obtain all the moisture they require from water falling outside the cloches.

It is important that the soil is moist enough before seed is sown to be covered with cloches. It may be necessary, for instance, to give the ground a good soaking in the summer before it is dug over for cloche culture. The moisture reaches down properly if this is done. However, most cloche sowings are made in the winter or early spring, when there will be plenty of moisture in the the soil. It is important that the top 50mm to 75mm should not dry out and the incorporation of compost can be very helpful. Once the cloches have been put into position over the seeds, they should not need to be moved and it should not be necessary to water under the glass.

After germination, the roots will reach down and obtain all the moisture they require. When rain falls, it percolates downwards and seeps sideways just below the surface, right to the centre of the cloches. The more organic matter there is in the soil, the faster the lateral movement of the water will be. Once your plants are established there is no need to water so long as there is sufficient rain outside the cloches. It is recommended to keep the soil just outside the cloche hoed so that the rain is absorbed and does not merely run off the caked top surface.

If there is no rain you can water your plants just as if there were no cloches over them.