Wondering what the general feeling is for all the self watering planters that have made it into the local retail shops. I am setting up my sunroom with some rather large specimens and don't want to run into trouble with wet feet or water logged plants. It seems like the larger plants suck these dry fairly quickly and smaller plants have quite damp soil. Any thoughts?
These can work good for outdoor summer container plantings, especially of annuals; the type that you have to water almost every day in the summer heat. Not so good for indoor tropicals though. Besides the much higher risk of overwatering, these usually aren't getting the flow-through/rinsing of the soil at every watering; and every drop of nutrient & water hardness & impurity that you add stays in the soil, building up and compounding over time as only the pure water evaporates. So they might work ok for awhile for some select indoor plants, but long-term they'll be weaker than a proper pot with normal watering and flushing.
Those little self watering trays are a nuisance. if you fill the tray itself, you aren't flushing or evenly distributing nutrients and if you don't take them off and empty the/clean them out really well at least once every week or 2 you end up with a problem. Mine was the fungus gnats breeding in them after I cleared them out of everything else and it got so bad i pitched the plastic tray for the self watering part and went to the ones that are easier to clean out. my outdoor plants had started growing some lovely algae also but we had quite a bit of rain. If you can afford it/make it/have a friend who can make you some, the unglazed ceramic pots with multiple holes in the bottom in a tray no deeper than about 1/3 of the pot's total height are your best bet (if you or your friend are making, be sure to put 'feet' on the bottom to keep the bottom of the pot at least 1 cm off of the bottom of the water tray). You can keep the big ones moist by flooding them, emptying the water tray then putting some clean water in it when you water. If you can't physically pick them up due to the weight, wet vacuums and clean dishrags work great - just use a bit of hydrogen peroxide in water to slosh around the bottom when you are cleaning it out. Clay is more breathable and less likely to accumulate moisture in the soil touching the actual container. Make sure if you go with custom made ones that they are not salt fired or glazed. You do want a high fire temperature because it will make them less likely to crack, but the salt fire will create a silicate (glass) buildup which is not porous enough to allow even moisture loss. You should post asking about soil compositions for your plant types that are drying out so fast and check to see if they are root bound by sliding them gently out of their pots and looking for roots making rings around the outside of the soil inside the pot. If they are root bound, that is most likely your problem keeping them moist and you may need to do some root pruning to thin the root ball before re-potting if it is really bad, your plants have not been producing new root growth, or you want to keep them in a similarly sized/the same pot. If you are still having issues keeping your plants at their ideal moisture level after putting them in ceramic with a good soil composition, you may want to consider setting up a hydroponic drip system for the ones that dry out too quickly. The stake and ring ones that you can stick around the base that shed small amounts of water work well to create a steady drip (and the ring is just a piece of light-proof rubber tubing that you poke holes in to cause it to drip so you can make it larger as your plant grows). In your case, I would not add nutrients to the water as it is just to keep the plant from drying out too much and not their sole source of plant food. You would still need to check your reservoir (which should be light proof) fairly often to make sure it stays full enough for your water pump to work. You would need a large plastic water reservoir, a water pump of an appropriate size for your water system, opaque flexible rubber tubing, the irrigation stakes, some regular tent stakes to hold up the 'ring' if it is larger than about 10 cm, and an outlet or extension cord near the reservoir. You may also want to get one of the soil moisture level testers so you can adjust the flow of water or turn off you drip system as needed to keep from drowning your plants. I don't remember the technical term for those and I am not sure which ones work best - I use the poke-your-finger-into-the-soil method to check mine which is not as accurate but still works.
Thanks for all the info about flushing the soil. Thanks to the big box stores (cheap pots) I now have about 10 of these pots in service, mostly for my larger specimen plants, hybiscus, palms, bird of paradise, etc. I think I will drill drain holes into the bottom and go back to the conventional watering method. My original thought process was that this will ensure I don't forget to water and loose my plants. I guess I need to get with the program and be attentive to the plants needs.
