I rely on a $10 garden store moisture meter; the kind with two long probes that indicates pH and light too. Is there a better method?
Dump it out of the pot, stick your fingers in the soil, learn what the top of the soil looks like when it is about time to water ...
Learn about your soil; is it sandy, silty or clayey? Estimating Soil Texture: Sand, Silt or Clayey? How deep is your topsoil, what is under the topsoil? Is it gravel, sand, silt or clay? - This will tell you about your drainage. Knowing all this will help you to develop right watering practices. Clayey soils should be watered less frequently than sandy soils, the same applies to badly drained soils. Badly drained clayey soils should be watered least frequently. Remember, too, that over watering can be more detrimental to the plant health than under watering. Monitoring the top of the soil only may lead to the development of a habit of frequent shallow watering which is the main cause of poor, shallow root growth and subsequent problems with the plant overall health, to the benefit of the manufacturers, advertisers and sellers of all kind of fertilizers, pesticides and fungicides, though. Water deeply but only when absolutely necessary. Remember however that newly planted trees, without well developed roots, need more frequent watering, let's say twice a week during the first year after planting.
I agree with everything you said except the last part about newly planted trees. In general, yes newly planted trees need more frequent watering but not always. I've learned this the hard way by watering once a week or less on some of my newly planted japanese maples and had deadly results. Even just once a week was too much for them. I've actually learned no watering gets the best results in all my planted jms unless drought conditions. For some reason my property retains enough moisture for them to thrive and they do not like being watered, newly planted or established. However, most other trees have benifited from weekly watering for the first year after planting. The rest of your post is right on, even for newly planted trees in some cases.
Thank you rufretic for your comment. It is always good to know other people viewpoint and learn from their experience. I agree that in the last sentence of my previous post I should add the clause "on well drained soils" (newly planted trees, without well developed roots, need more frequent watering, let's say, on well drained soils twice a week during the first year after planting). It looks like your soil is very moisture retentive, probably clayey, probably without good drainage. On such a soil watering too often could be very detrimental. My soil is sandy, very well drained (I have at least 400' of sand and gravel under my topsoil), the climate is hot and dry during summer. For best results I water my newly planted trees or shrubs about twice a week during first few months (June, July, August and September) after planting. So, for the question "how often to water?" the answer is "it depends". It depends on the soil, the climate, the plant itself (some are moisture loving, some not), is it newly planted or already established?
Well said! Just don't want anyone who may have a situation like mine to have to learn by killing a few maples. My yard is not the typical but yes my soil has clay in some areas. The top layer drains pretty well or I don't think I would be able to keep my japanese maples alive. I think the largest reason my area stays moist is because I am surounded by natural oak forest. I have moss and ferns growing freely on much of my property which is another pretty good indicater it stays pretty moist. Your statement pretty much sums it up:
