I'd say that the water from your tumble dryer is probably safe to put on plants.
But Duff please note the use of that weasely word '
probably'.
To cut out the guesswork you need to be really sure of what type of waste water you have ended up with. And to be sure, you first need to ascertain the pH value of the water in your tumble dryer...that's because plants are notoriously very picky about the alkalinity or the acidity of the water they sit it. The level of alkalinity or acidity of the waste water will either make your plants thrive - but get it wrong and it will kill them stone dead.
Fortunately there are plenty of ways to test the pH value of water and you could just google the words...
Ways to test the ph level of water . I won't babble on, it is best if you read what WikiHow has to say. You can simply double click on
https://www.wikihow.com/Measure-the-pH-of-Water and get all the info you need.
To cut a long story sideways, WikiHow says that the best (and simplest) way to test for pH is to use a gizmo called a
pH meter. I heartily agree with WikiHow - and I can give you some more really good news...you can pick up pH meters from Amazon for as little as £3.99.
To recap: It is absolutely essential that you test the alkalinity or acidity of your waste water before you splurge it all over your garden - and a cheap pH meter is the best way to be sure
before you go merrily asplurging. Get the pH level right and you'll be rewarded with a lovely garden - but get it wrong and your garden will soon be a barren necropolis of plants.
Then, depending on the measured results, you can either google
Plants that like acid water or
Plants that like alkaline water and you learn which of your plants to drench with tumble dryer water or not.