Death by watering Part 2

As promised, here are some photos of Japanese maple seedlings growing in an extremely dry environment. The pictures are quite small so I've put a link to a page on my web site where you can see bigger images; just click on the first picture. The first picture shows a general view of the tunnel that was used to grow understock; you'll notice that all the plants are red maples; the reason being that if the graft fails I still have a atropurpureum seedling to sell as they are always more popular than green forms. Even the experts such as myself(!) are not infallible! These photos were taken in April and the plants have just come into growth. The overhead irrigation lines were dis-connected when the crop, of which these seedlings were part of, was lifted thirty months prior to these pictures being taken.

The second picture shows the seedling in the centre of the tunnel whilst the last picture shows plants near the side of the tunnel. Notice that they are slightly larger due to condensation running down the inside of the film as indicated by the presence of moss next to the film. Also, because they are at the edge of the tunnel, they are the first to get the benefit of any deep moisture that migrates through the soil. The film is buried in a trench fifteen inches deep but moisture will still creep in as nature abhors an imbalance. Shade temperatures in the summer get up to 100 deg.F and the soil in the tunnel would have been bone dry but there would always be a small but constant supply of moisture at about two feet or possibly lower with the tunnel cover acting as a mulch to prevent fluctuations in moisture levels. Even in that environment, if I'd put a sheet of polythene on the ground, the soil would have been damp right up to the surface!

I hope that I've succeeded in showing you that watering a Japanese maple once it's been planted can be a dangerous exercise and that they are better left well alone. As water becomes increasingly scarce and expensive, particularly if your local utility has decided to ration it or impose a hosepipe ban, it is far better to let your maple fend for itself; they're much more intelligent than us when it comes to knowing what it's needs are as they've been doing it for a very long time!

Of course, all the above pre-supposes that you have a healthy plant waiting to be transplanted. The reality is likely to be somewhat different as most purchased plants exhibit some degree of poor health and may well need a period of convalescence before they're ready to go out into the big, wide world. This is another subject in need of a visit and I shall go into it in some detail in the near future.

Need more information? Get it at growing Japanese maples.

Death by watering

First, my apologies. The illustrations of Japanese maples growing without water will have to be postponed until later in the week. The raw pictures need to be processed before they can be uploaded but over the weekend I took advantage of the break in the weather to make a start on seed collection.

When it comes to watering Japanese maples, particularly during late spring and summer, most people will regularly apply water to the soil without understanding the affect this has on the plant. In hot weather most of the water will evaporate very quickly and what's left will moisten only the very top of the soil. The act of watering will also compact the soil and build up a barrier to air and water.

The fine feeding roots are encouraged to move up to the surface in search of moisture but if the surface is allowed to dry out between watering, very likely in hot weather, they can be killed by lack of moisture and heat build-up. Symptoms of so-called leaf scorching can lead to more water being applied to the extent that the surface becomes waterlogged and the feeding roots die through suffocation.

If no water is applied at all, the roots will gradually move down into the soil, following the moisture over the course of the season and a far healthier plant will ensue. There will be periods however, especially during late summer when soil moisture levels are at their lowest, when some leaf scorching can occur. For the reasons stated above, giving your Japanese maple a 'good soaking' is not going to help at all.

The ideal solution, therefore, is to mulch the plant and the best mulch is going to be a sheet of polythene. This can be held down by gravel, pebbles, wood chip or any material that is going to look more attractive than polythene sheeting! The purpose of this exercise is to trap moisture below the barrier and this will be fairly constant, allowing the plant to get all the moisture it needs without being stressed. Natural rainfall won't have any affect on levels under the barrier but will gradually move across through the soil avoiding any peaks.

To give you an example of this method in practice, lift up a paving stone or any other object that's lying on the soil surface and you will notice that the moisture has been trapped under it. Perversely, the hotter the weather, the more moisture is drawn up through the soil as the moisture is heated and rises, corresponding with an increase in the water requirements of your maple.

With this method, your Japanese maple will have an adequate supply of moisture throughout the growing season without the risk of stressing it due to fluctuations in watering.

Need more information? Get it at growing Japanese maples