It's Teacher Appreciation Week! And plants make ideal gifts for your favorite teacher. Unlike cut flowers, plants can last a long time, growing and getting bigger and better each year (and with each class of students). Plus, lots of plants are wonderfully efficient at purifying the air, making the classroom safer and healthier for both the teacher and students. A number of scientific studies show that having plants around can also help improve our mood, lower stress levels, and increase memory and problem-solving skills. 

While just about any plant makes a perfect gift, here are five we think will earn high grades from teachers:

Orchids.

Beautiful, elegant, and much easier to care for than most people think, orchids are ideal gifts. Their blooms last a long time -- up to three months or more -- and reappear every year when the plant is watered regularly and has good light levels (in general, good light for an orchid is if there's enough light most of the day to be able to read an essay page without having to add supplemental lighting). Plus, orchids come in a wide range of flower colors, from pure white to deep purple, so it's easy to personalize an orchid.

Colorful and Red Aglaonema.

While the name is a bit of a mouthful, the plant couldn't be easier to grow. It's amazingly tolerant of just about every care condition, from infrequent watering to low light. Colorful and Red Aglaonema offers its cheery leaves all year long, adding a delightful splash of color to the classroom. There is a range of varieties available, as well, so you can match a plant to the teacher's favorite look. 

Desert Gems Cacti.

The most colorful cacti you'll ever see, Desert Gems offer a range of jewel-like colors that practically glow! While, like most cacti, Desert Gems do have spines, the spines are smaller and softer, making it a little more friendly to have around kids. (That said, children shouldn't handle Desert Gems cacti unattended.) Desert Gems are easy to grow, too -- all they need is bright light (enough to cast a h2 shadow most of the day) and watering once every 10 to 14 days. 

Anthuriums.

Anthuriums are a fabulous flowering plant that can bloom on and off throughout the year. The flowers typically come in shades of red, white, and pink, but you can also find types that have lavender, orange, or even multi-color striped flowers! The blooms are long-lasting, too -- they can go weeks longer than a bouquet of cut flowers. When not in bloom, anthurium's glossy green foliage looks attractive. And it's one of the most efficient air-purifying plants around! 

Peace Lily.

Peace lily is a delightful, easy-care relative of anthurium and has similar flowers, but in pure white. It has shiny, dark green leaves that make a great backdrop for those fun flowers. It's also one of the best air-purifying plants available, making it ideal for classrooms. While many plants will suffer if they're overwatered, peace lily doesn't mind having wet feet, making it a great choice for teachers -- or students -- who might tend to overwater. 

Written by Justin Hancock