I don't quite follow Paul. When I water I take the plant pot out of the plant holder and put it on top of a couple of lollipop sticks in a shallow aluminium dish about one to two inches deep. The lollipop sticks ensure that the pot is slightly above the base of the tray so the water can get under the base. I pour water directly into the tray until it is just below the rim of the tray, I don't water from the top apart from the misting. My reasoning being that the roots will "drink" whatever water they need in the hour or so that I leave the pot in the tray. When I lift the pot out I let it drain before putting it back in the plant holder. The plant holder has a couple of inches of small pieces of welsh slate in the bottom to ensure that the roots don't get soggy. I estimate that the plant takes up much less than half a litre each week so I can't see how i'm watering more than you would?
Thanks for the tip about giving the plant a plunge, That's on my list of things to do. I'm going to stop using rainwater from the water butt and put a couple of large buckets down the bottom of the garden to catch the rain.
Many thanks for the advice, top man
Just read my reply. Apologies for the length of post!!
OK. I see the confusion, my fault. I'll try to explain. There is nothing wrong with your regime, you're clearly putting a lot of care and attention in to your plants. This is excellent and suggests your creosote idea may well be correct.
I only ever use tap water. I will feed once every 3-4 waterings in winter. I've just switched over to feeding every other watering as we're entering spring and I can see growth.
A soil or compost is full of spaces which hold water or air. When we plunge a pot in to water so the compost surface is underwater bubbles rise to the surface, this is air being forced from the soil spaces as water fills these spaces. When the bubbles stop all the air has been on forced out of the compost and replaced with water. Technically this is known as "field capacity" which is the maximum amount of water a given volume of soil/compost can hold. When we stand the pot to drain the excess water the compost cannot absorb drains away.
Roots need access to both water and oxygen via the soil/compost. If a pot is always wet there will be no oxygen in the soil pores, this is what causes death from over watering. Good watering is a balance between providing adequate water while retaining adequate oxygen.
The difference between our regimes is this. You are watering weekly but it sounds to me you never allow the compost to dry out. While this is not wrong it does mean the plants are always sitting in a compost which contains relatively little oxygen. You said the roots are "drinking," they're not, the compost is simply absorbing all the water it can.
In winter my plants are dry. If I pull a plant out of its pot the root ball will be dry - small amounts of compost will fall away from the root ball at the slightest touch. When I water with 0.5/1.00 litre all of this is absorbed by the compost. No run off or water draining out. I watered today, my five feet tall Kentia palm was given a one litre feed! In my view the plants aren't growing so only need sufficient water to sustain themselves. It's easy to add more if needed. Removing water from a wet compost is impossible.
In spring/summer when the compost is dry I plunge the pot under water, wait for most, not all, bubbles to stop and then drain. Alternatively I stand the pot in water as you do until the compost surface is moist. This has forced much of the air out of the compost BUT at this time of year my plants are taking up a lot of water, taking the water out of the compost which allows air back in to the compost. I do this when the compost is dry, not on a regular basis. Quite often I'll notice something wilting, then it gets watered.
I hope I'm clear, if not please ask. I don't think your regime is wrong but have the impression your plants will be quite moist all year round. I'm not sure they need to be.
Keep in mind I'm a hardened ex-grower. I tend to apply my ideas to the home and allotment. For example when I plant out on my allotment I give a single watering. After that the plants fend for themselves. Why? I want root growth, if there's no water the roots have to grow to find it!! Keep giving the plant the water it needs and it won't produce more root!! Why bother it's wasted energy.