the
washington
post
.
thursday,
june
9
,2022
DC
10
high school students, partici-
pants looking at real pansies for
three minutes felt more relaxed
and comfortable than those
looking at artificial ones. Gu’s
point about mood effects beyond
visual cues may help explain
these findings.
Placement: Although re-
search on this is sparse, some
studies suggest that having
plants closer than 10 feet to
a person has a positive mood
effect. A study by Knuth of
North Carolina State shows that
most people put houseplants in
living rooms, bedrooms and
sometimes kitchens. With the
expansion of working from
home, placing plants in home
offices or other work areas can
be helpful.
It’s important to remember
the caveats of many of these
studies: Some were carried out
in highly controlled settings and
primarily among college stu-
dents. They reflect snapshots of
time rather than long-term ef-
fects. And their real-world impli-
cations for a more varied group
of people — for example, among
older adults or those in low-re-
source environments — may be
different. But it’s hard to ignore
the volume of research showing
that houseplants have a signifi-
cantly positive effect on mood
and physical health. So, as we
find ourselves spending more
time indoors — whether because
of the pandemic, work or weath-
er — perhaps it’s time to pick up
some houseplants.Lala Tanmoy Das is an MD-PhD
student in New York City doing
research in molecular cardiology. Find
him on Twitter: @TanmoyDasLala.theory. Studies have found that
the plant-induced “restoration” ef-
fect has a wide reach: renewing
positive emotions and increasing
productivity, creativity and atten-
tion capacity.A data-driven guide to
investing in houseplants
How do you choose what
houseplants to buy? Research
can provide some practical guid-
ance:
Number of plants: Although
there is no magic number, hav-
ing five or more foliage plants
can increase positive emotions.
For example, in one study, par-
ticipants in a room with bamboo
palms, Chinese evergreens and
heart-leaf philodendrons (five in
total) felt more carefree and
friendly compared with those in
rooms without plants. Alterna-
tively, one tall potted plant
(about five feet) or three or more
small floral displays (such as
sweet pea, larkspurs or wood-
land sage) can elicit similarly
positive responses.
Color: The greener, the bet-
ter? In a study using English ivy,
green-yellow and bright-green
leaves increased feelings of
cheerfulness and relaxation,
whereas whitish-green leaves
stimulated mostly negative emo-
tions. As for flowering plants, a
study found that purple, green,
red, pink and white ones could
lower people’s blood pressure
and heart rate. However, purple
and green flowers were more
effective in relaxing the body,
reducing anxiety and improving
mood. Another study found that
red and yellow roses elicited a
more calming response than
white ones.
Real vs. artificial: In an in-
door space, having any type of
greens — including photographs
of plants — is better than having
none at all. However, real plants
have a greater mood, attention
and relaxation effect than faux
plants. The same applies for real
vs. faux flowers. In a study of“it is not only seeing a plant that
improves our mood so quickly, but
the smells can also make a huge
difference,” although studies on
plants’ effects on nonvisual senses
are limited.
Plants bring relief in enclosed
spaces. If you are stuck in an
office or other small space for
hours at a time, plants can bring
about feelings of escape. In a
study conducted during pandem-
ic stay-at-home orders, partici-
pants who had indoor plants ex-
perienced significantly fewer
symptoms of depression and
anxiety than those who did not.
Being surrounded by houseplants
led to feelings of “being away”
from social or physical demands.
Plants can reduce stress. Oth-
er studies have shown that inter-
acting with plants suppresses the
system in our bodies that gets
activated when we sense distress
signals. Young adults in one study
who spent a few minutes repot-
ting and transplanting an indoor
plant reported feeling a lot less
stressed at the end of the task
compared with peers engaged in a
computer-based activity. In addi-
tion, blood pressure measure-
ments were much lower among
people who handled plants, sug-
gesting that plants have the po-
tential to mellow the body’s fight-
or-flight response.
Plants can recharge us. “Plants
also have a huge restorative capac-
ity,” said Melinda Knuth, an assis-
tant professor of horticultural sci-
ence at North Carolina State Uni-
versity. “Whether it’s outdoors like
in a yard or indoors with house-
plants, nature can help us feel
recharged and grounded.”
When we focus on demanding
activities for a long time, such as
our jobs, it can lead to mental
fatigue and negative emotions
that can affect how well we can
pay attention. Seeing a plant in
this situation can provide a spark
of interest, redirect our attention,
and restore our depleted mental
and physical resources, an idea
known as attention restorationPeople and plants are naturally
connected. Humans have an inher-
ent connection to plants and other
living things, according to what’s
known as the biophilia hypothesis,
an idea popularized in 1984 by
naturalist and writer E.O. Wilson.
Since then, more than three dec-
ades of research spanning the globe
have confirmed the hypothesis and
shown that natural environments
have a sizable effect on increasing
positive emotions and decreasing
negative ones.
“When people state the com-
mon belief that being in nature
relaxes them, that it helps them
recover from stress and tragedy,
that it’s a healing process to be in
nature, we now know there’s a
solid basis for that,” Wilson said in
a 2015 interview with The Wash-
ington Post.
And when people started
spending more time indoors,
we brought in pieces of the natu-
ral world to continue feeling
connected.
Plants can quickly improve
mood. Our connection to plants is
so strong that sometimes it takes
only a few minutes of being in
their presence to start feeling bet-
ter. Studies have found that less
than 20 minutes is enough to
make us feel more at peace. In one
experiment, participants who
spent even five to 10 minutes in a
room with a few houseplants felt
happier and more satisfied than
those in a room without plants. In
another study, participants felt
more peaceful and positive after
spending 15 minutes in a room
close to a tall plant (about five
feet) compared with other objects.
However, Gu reminds us thatFROM PREVIOUS PAGE
How houseplants affect our mood