Can I convert my bathroom into a green house?

Have you thought about these?
I have never used them, so I don’t know if they work.

I haven’t but I have a cousin who tried them out and she said it didn’t work so well. I would also have to buy a lot of them.

String method watering is all I’ve ever used when I know I can’t be around. But, I have done both plastic bag method and saucer method (seen at same link) for outdoor plants or seedlings.

If doing string method, the video shows twine being used. I personally recommend cotton string, not twine for watering.

Having a moist environment would certainly help, but can you count on it being warm enough at the end of May to promote maximum humidity? I have used Soil Moist granules indoors and out in pots to lengthen the times between waterings.

I would recommend the wick method too. That much humidity will raise hell with your bathroom.

I have a FSIL (future son-in-law) who creates his own “water globes” as suggested by @chyna.
He takes plastic jugs (soda, water, whatever) fills them with water, puts the caps back on, punches holes in the cap and then sticks them in the dirt upside down. They leak out water over the course of several days.
You can regulate the flow by poking more or fewer holes in the caps and, by experimenting, adjust the rate to the particular soil conditions in your pots, the needs of the plants, etc.

I use the watering bulbs when we go away.

@Cruiser uses the watering bulbs, so I believe they must work. I don’t know why you couldn’t get the same effect with the cheap condiment (mustard and ketchup) dispensers from the Dollar Store.

Or just use @SpatzieLover‘s string method. I agree with @Adirondackwannabe that a high level of humidity in your bathroom for that long is going to play hell with the bathroom.

I remember my parent using a variation of the string method using newspaper. They sat the plants on wet newspaper with a wick of newspaper into a tub of water

This is an engineer talking. You have a month to work out a perfect solution.
First, you need to know how much water you need per plant, per day. That will bound the problem and tell you how much total water you need and the delivery rate. Measure your water for a couple of days so you know what is needed. Are you talking many gallons for many plants? You might be able to make a siphon and use water from the toilet tank. First you need to know how much is required.

I woul dnot make my bathroom – or any room – moist. I’d be afraid of growing mold.

Perfect solution. String method from the toilet tank. It will refresh as needed.

@ibstubro That is where I was headed. If only a gallon of water is needed, then I’d use a gallon jug sitting on the top of the tank. If much more is needed I’d go with the toilet tank since it automatically refills when low.

I would tie the strings to washers so the tank end would sink to the bottom and stay wet.

Another approach could be to use a cheap timer and a small fish tank pump with the toilet tank as the source. Maybe it only needs to run 1 or 2 minutes per day.

An added benefit to either the granules or the Aquaglobes is that you wouldn’t have to move all of your plants into one area. Each pot is self sufficient.

The granules and the aqua globes just aren’t sufficient at keeping plants moist enough.

Another thing I do to boost moisture is to add moistened coconut fiber into the potting soil, then top off the pot with moistened moss. This is best for plants where you want no drying out between waterings.

@SpatzieLover : I guess it depends on the type of plant, but I have used the granules for years with great success, water heavily just before I leave, and the soil is still not dry after 10–14 days. Mostly with herbs and small peppers. I wouldn’t recommend not watering developing tomatoes or squash for that long.

Yes, that’s what I logged on to add, @LuckyGuy. I’d tie stainless steel washers on one end and drop in the tank, tie paper clips (or the like) to the other end and shove in the soil until the string is buried.

@SpatzieLover Holy crap….that string method is so simple, awesome. Do you find it works really well?

Hey it worked. ( The tub idea) My plants survived two weeks without watering and are green and healthy.