Are there concrete plant-watering schedules?

Question

I'm in the progress of making more of my house plants survive, better. (I'm doing OK, but too many of my plants die, or sometimes suddenly nearly die for mysterious (to me) reasons.)

I've started looking up a whole bunch of my plants, and while I found vague instructions (e.g. "keep moist" or "water when the top 1in/2.5cm are dry"), but rarely anything specific (e.g. "water every 5 days"). At the same time, there are very clear/specific instructions out there for fertilizing!

My plan right now is to create a list of the various watering rules, monitor each of my plants daily for a month or two, keep track of when I water them, and then build a "static" schedule (water plant A every 2 days, plant B every 7, plant C every 8) that I can set up as recurring reminders.

Is there a better way? Does everybody do this?

Answer 1

There are no concrete watering schedules because it's not viable - there are too many variables, so it's according to need. For the majority of houseplants, the general rules are:- the plant should always be in a pot with drainage holes; when the surface of the soil feels just about dry to the touch, water thoroughly, allowing excess to drain away freely, and empty out any outer pot or tray after 30 minutes so the plant is not left sitting in water. There are exceptions - cacti and some succulents may require much less water and less often, and certain plants may need to be kept damp all the time, though not waterlogged..

How often you need to follow this routine will vary according to the temperature of the room, the size of pot and plant, whether the plant is in sunlight or not, and whether the plant is actively growing, or has slowed down for winter. Plants require more water during the growing season than they do in winter, unless they are kept in very hot rooms when they may need a little more. In my own home, I check mine about every 5-7 days, when they usually require watering, though flowering plants may need water more often, but it varies according to the factors mentioned above.

Answer 2

It is difficult to have a general rule. Some irrigation system (also for pots) have a humidity sensor, so that the system could adjust itsself. But also in this case, it requires user input, according the type of plant (desert or wetland plant). Pot size and plant size is also relevant..

Also on large irrigation, true gardeners will adapt every week or two the amount of water (regardless weather sensor): different vegetable stage requires different amounts.

In general: potted plant requires more often watering (pot soil do not retain much water: normal soil on pot will rot). If I remember correctly, the holiday kit of Gardena tell us to water every 8 hours, for very short time. I would go with less watering (one or two per day), but I would try the usual method (see Bamboo): check how much water a pot could contain, and adjust watering. Indoor you will have more controlled irradiation ("sun") and temperature, so it could be easier to build an automatic system.

Plants cannot move, so they should be able to cope with different weather conditions, so usually they could resist on "wrong watering" (within limits). Just some plants are very delicate, but there are two cases: not sold as house plants, or they are Orchids. So if you have a difficult plant, you will have also much more literature on how to care such "special plant".

Note: outdoor irrigation is totally different (the rule is water more but less frequent, so around twice a week, but also it depends on climate and plant), so you should always be careful on interpreting water data: it was for potted plants, or for outdoor plants.