The first thing to realise is that no plant on the planet is truly an indoor plant. All plants evolved outdoors and that is the environmental condition they need to thrive. What is really meant by indoor plant is that the environmental conditions inside houses (low light, low air movement, no rain) are tolerable for the plant. But the plant is unlikely to thrive it kept indoors exclusively.

All of these plants are rainforest understory plants (except the baby breath, I have no idea what plant that is). In the rainforest they are subjected to high humidity,. low light and little air movement, and frequent rain.

You need to try and mimic those conditions as much as possible. Most ambient light (except direct sun through a window) i still too low a light level even for a rainforest understory plant. If kept indoors 100% of the time they will eventually die. You need to rotate they plants into a protected outdoor spot at least once per week to keep them healthy.

The other thing to remember with nursery plants is this.

1. Most of them are already very pot bound by the time you purchase them. This means they have outgrown their pot and need to be transplanted into a larger vessel with more soil as a matter of urgency if you want them to live. It's very important with these plants that you use the proper potting mix, orchids especially do NOT live in soil. They live in a special mix of dry matter designed for orchids. Don't even attempt to plant them into normal potting mix, Ferns need a mix that retains a lot of moisture and allows air into the roots. Bamboos are a completely different type of plant again.

2. Nurseries keep these plants healthy by over-feeding and over-watering them. They use a sprinkler system that feeds all of these plants a weak fertiliser mixed into water several times per day. They have to because the plants have already exhausted all the nutrients out of the potting mix. If they didn't the plant would already be dead. You don't have one of these systems inside your home. You need to do more than just tip a little bit of tap water on them each week. A good safe bet is to buy a small bottle of seaweed liquid fertiliser and use that mixed with water every single time you water the plant. You should also get a spray bottle and use the same mix in it every SINGLE day. This keeps the humidity in your home up to what the plant is used to as well as foliar feeding it, the plant is also used to that.

If you've ever wondered how you managed to kill every single plant you've ever purchased from a nursery this is the reason. I used to have the same experience. But once I repotted every single plant I purchased on the same day into a larger pot with fresh potting mix then fed it with a misting spray bottle I suddenly developed a green thumb.

Nurseries don't do this to trick you, the reason is simple. Smaller pots are cheaper to use. They use less potting mix, they take up less space on the nursery shelves enabling more plants to be offered, smaller plants can be sold at a cheaper price, moving stock along. But you have to be aware that 99% of the time that plant which looks so healthy is in desperate need of a new pot and plenty of food. Provide it.

Whenever I buy a plant at a nursery I also buy it a new pot, and new potting mix. If this seems too much then buy fewer plants. I never leave a nursery plant in it's existing pot for more than 24hrs. A plant that dies is the most expensive plant there is, one that doubles in size and becomes a lovely part of the home or garden is good value.