health and wellbeing series houseplants and office · – miracle-gro – fafard (quebec company)...

McGill Health and Wellness Series:

Office Plants for your Health

What We’ll be Covering

• Houseplant benefits.• Houseplants for the office.• Houseplant care:

– How to water– Differences in soil– Pots, and how to use them.– Fertilizer…?

• Common unhappy houseplant symptoms.

Houseplant Benefits

(Larsen et al. 1998; Shibata and Suzuki 2002; Han 2008)

• Several studies using different experimental designs have linked the presence of houseplants to a range of positive psychological and physiological benefits.

Psychological Benefits

• Fjeld et al. 1996:– Fatigue symptoms 30% lower in

offices with plants.• Rappe and Linden 2004:

– Plants in nursing homes greatly benefitted the mood of patients.

• Larsen et al. 2005:– Participants reported increased

levels of comfort with plants.• Bringslimark et al. 2007:

– Self-reported greater productivity and lower stress.

(Kaplan and Kaplan 1989; Ulrich et al. 1991; Kaplan 1995; Larsen et al. 1998; Shibata and Suzuki 2002; Han 2008)

Psychological Benefits

• Lohr et al. (1996) Journal of Environmental Horticulture:– 96 students– Looked at images with and without

plants in the room.– Image recognition test– With plants:

• Better test results• 12% faster• Felt more attentive• Smaller rise in blood pressure while

performing task (less stress)

Physiological Benefits

• Include:– Faster post-operative

recovery time (by 1-3 days).– Fewer post-operative

complications.– Lower heart rates.– Lower blood pressure. – Greater tolerance to short-

term discomfort.– Fewer sick days from work.

(Fjeld et al. 1998; Lohr and Pearson-Mims 2000)


• Fjeld et al. (1998) in Indoor and Built Environment:– 51 subjects randomly exposed to

extended periods with and without plants.

– Study assessed neuropsychological, mucus membrane, skin symptoms.

– Plants = 37% reduction in cough, 30% reduction in fatigue, 23% reduction in dry/hoarse throat and skin dryness.

(Fjeld et al. 1998)


• Park and Mattson 2008:– Compared 90 appendectomy

patients before and after surgery.

– 45 in plant rooms, 45 in rooms without.

– Plant room patients:• Needed fewer pain medications

after day 3• Lower heart rate before and after

surgery• Lower systolic blood pressure

before and after surgery.• Lower rates of anxiety, fatigue

(self-reported)

(Fjeld et al. 1998)

Houseplant Benefits

• Why would houseplants positively effect health and stress levels?

• Psychological benefits hypothesis:– We evolved around green spaces,

they still relax us!– Low stress = better health!– But may be a placebo effect.

• Also… air quality improvements!

(Fjeld et al. 1998)

Air Quality

• The great indoors is a harsh place:– Low humidity– High ambient CO2– High microbe count in air.– Volatile Organic Compounds

(VOCs)• Toxic compounds released by

many common household items.

– Paints– Cleaners– Printer ink

(Brown et al. 1994; Orwell et al. 2006; Solomon et al. 2008; Burchett 2009)

Air Quality

• Increase ambient humidity.– Release water vapor from

leaves.– Indirect effect of watering.

• Decrease CO2:– Stomata in leaves takes CO2

out of air, releases O2.– Microbes in soil also

sequester CO2.• Best benefits removal of

VOCs and particulate matter.

(Brown et al. 1994; Orwell et al. 2006; Solomon et al. 2008; Burchett 2009)

Air Quality

• Can remove 100% of some volatile organic compounds– Effectiveness varies by species– Function of both plant and soil.– Soil microbes take up some

VOCs, break them down or sequester them.

– Plants can take some up directly through stomata and through roots.

(Tarran et al. 2002; Orwell et al. 2006; Liu et al. 2007; Burchett 2009)

Air Quality

• Formaldehyde example– Wolverton et al. 1984– Common VOC– As little as ~50 ppb can cause

adverse health.– Chlorophytum elatum var.

vittatum (spider plant)• 37 ppm to <2 ppm in 24 hours.


Air Quality

• Have also been used to remove unpleasant odor molecules indoors.

• Oyabu et al. (2003):– Plants in nursing homes– Removed hydrogen sulfide,

ammonia and methyl mercaptan through leaves.


Air Quality

• Particulate matter:– Wolverton and Wolverton 1996.– Compared plant filled and empty

rooms in real homes.– Microbes examined included fungi

and bacteria.– Airborne microbial levels 50%

higher in plant-free rooms after just 48 hours.

• Modes of action:– Antimicrobial compounds released

by plants – Soil uptake.


Houseplants for the Office

• Office environment is hostile to many plants.– Poor light– Dry air– Temperature extremes

• However some plants can thrive in these conditions.

Office Plants

Office Plants


• Plants we recommend:– Jade plant– English Ivy– Mother-in-law’s tongue– ZZ plant– Begonia– Inch plant– Spider plant– Golden pothos– Christmas cactus

Office Plants


• Make your space more plant friendly!

• Artificial office light is very poor for plants.– Missing a wavelength crucial to

plant growth.• Can buy a cheap plant light

which provides all the light a plant needs, even indoors!– Comes as a halogen light or

normal light bulb.

Caring for your Plants.

Watering

How to Water

• #1 way people inadvertently kill their houseplants.

• There is a proper technique!• Too much water kills faster

than too little.– “Killed with kindness”

• Most houseplants like to dry out between watering.

Rules of Watering

• Always have a watering tray.– Never have your plant in a pot

without a drainage hole.

• Water with lukewarm water.• Water when the soil is completely

dry (for most species).– A soil moisture meter can tell you for

sure!

• Water until a little bit of water drains from the bottom of the pot.– If a LOT drains, pour out the water.

What is Soil?

• Soil is your houseplant’s entire world!

• VERY important.• Can be made of many different

things:– Peat– Sand– Little rocks (vermiculite and perlite)– Styrofoam

Types of Soil

• Different plants need different soils.– Soils differ by how well they retain

water.• Peat holds water well, sand drains

quickly, ect.– … and how well they retain fertilizer.

• Vermiculite, perlite and Styrofoam do this.

• Most houseplants are tropical.– Like ‘water retaining soil’.– Most ‘houseplant soils’ are water

retaining, with lots of peat.

Types of Soil

• Specific soil mixes now available in many stores:– Use appropriate soil where possible.– “Cactus soil” for cacti species, ect.

• Never buy dollar store or no-name brand:– Sub-par soil.– Your plants will suffer and may die.

• Best brands:– Miracle-Gro– Fafard (Quebec Company)

Types of Pots

• Many different styles and varieties to choose from.

• Decorative vs. the actual pot.– Many new decorative styles.– Difference:

• Decorative have NO drainage holes.– NEVER have your plant in a

decorative pot alone.• No drainage = dead plant.

• Plant in a cheap plastic pot, then put plastic pot inside decorative pot!

Repotting

• ALL plants will eventually need repotting.– Frequency depends on the species.– If roots are coming out the bottom of

the pot, it’s time.

• Choose a pot at least 2 cm diameter larger than the previous one.– Will increase the time to the next

repotting.

How to Pack a Pot

• Bottom of pot:– Can put rocks or Styrofoam to increase

drainage.• Necessary is you plant in a decorative pot!

– If you don’t want soil falling out of drainage holes, cover with a coffee filter!

• Planting the plant:– Leave ~1cm of the pot above the soil

line.• Will make watering easier.

– Try to cover the old soil with a layer of new soil.

Fertilizer

Fertilizer

• All houseplants benefit from fertilizer.– Some need it to survive!

• The more often you repot, the less you may need fertilizer.– Many soil mixes now contain some level of

fertilizer,• MANY different brands and

concentrations.• Three numbers on the front:

– N-P-K– N: Nitrogen � Leaves– P: Phosphorus � Flowers and fruit– K: Potassium � Roots and immune system

Fertilizer

• Higher number of one relative to the other two:– Trying to emphasize that type of growth.

• Balanced fertilizer has equal numbers:– Ex: 20-20-20

• Most fertilizer brands tell you what they’re good for!

• Too much fertilizer WILL cause problems.– Follow the label!

Common Problems

Leaf Problems

• Leaves with curling dry ends (common in ferns)– Humidity is too low!– Mist plants periodically.

• Sticky or shiny leaves:– You have a bug infestation, check for

other symptoms to figure out which one!

• Leaves with brown edges.– Watering problem. You are watering

too much or too little.

Leaf Problems

• Little black dots on leaves:– Those are likely insect faeces.– Check for thrips or caterpillars.

• Yellowing of leaves between veins.– Your plant is suffering from a nutrient

deficiency. – Fertilize it right away!

• Leaves getting large spots which are light brown and crispy:– Have you moved your plant recently?

It’s now getting too much sun and the leaves are burning.

Overall Problems

• Plant getting long and straggly (lots of stem between leaves).– Plant is not getting enough sun and is trying

to grow towards the sun.• Entire plant is wilting:

– Likely it has been overwatered very severely or underwatered very severely.

• Will recover from underwatering, not overwatering.

• Lots of leaves are starting to die (oldest first), but the plant was doing well before.– You probably need to repot.– When stressed, plant will kill its least

efficient (oldest) leaves first.

Overall Problems

• Plant declining slowly, with no obvious cause.– Is it in the appropriate soil?– When did you last fertilize it?– Did you move the plant to a

darker spot in the room?– When did you last repot it?

• Go through this list, and you should be able to figure it out.

Conclusions

Conclusions

• Even a few plants can have a profound impact on your mental and physical wellbeing!

• Try new plants! Don’t feel discouraged if some die.– The people with the most

houseplants have also killed the most houseplants!


Thank You.

Questions?

Pests…

The Big Bad Five

• Five most common insect pests:– Mealybugs– Scales– Spider Mites– Thrips– Fungus Gnats

• Important to know how they reproduce, and how they spread.

• Also, always isolate an infected plant!

Mealybugs

• Looks like a white fungus.• Lays eggs in the plant itself, or can give

birth to live young.• Moves from plant to plant by crawling.• Control:

– Safer’s Soap– 50:50 ratio of isopropyl alchohol and water,

with 1% detergent.– If houseplant is cold tolerant, place outside!

• Mealybugs are tropical, they can’t stand the cold.

Scales

• Looks like a brown spot on your plant.

• Also moves between plants by crawling.

• Similar lifecycle and control as the mealybug.– On broad-leaved plants, you

can also wipe them off with a cloth.

Spider Mites

• Little red bugs that make webbing on your houseplant.– Gets its name from the webbing it makes.– Less than 1mm long, you’ll see the webbing

but not the bug.• Doesn’t mind the cold, can’t kill by

putting the plant outside.• Crawls between plants.• Reproduces VERY quickly.

– 5 day lifecycle, and each female lays 100s of eggs.

• Spray with an insecticidal soap, and spray LOTS!

Thrips

• Tiny, VERY problematic bug.• Will likely see damage and

poop, before you see the insect.

• Adults can fly. – An infestation can quickly get

out of hand!

Thrips

• Immediately quarantine infected plants!– Putting them outside is best.

• Let the soil dry out as much as possible without harming the plant.– Larvae need wet soil to thrive.

• Spray every inch of the plant with Safer’s Soap (bottom AND top of leaves).

• Pray.

Fungus Gnats

• The traditional office “little fly”.• Little black flies.• Larvae live in soil.• Two ways to control:

– Let your soil dry out completely before watering.

– Use yellow fly tabs.• The gnats are attracted to yellow.

• For a VERY bad infestation, use “pantyhose” method.– Cover the top and bottom of your pot with

pantyhose.– Air can get through, but gnats can’t! So

nowhere to reproduce!

Literature Cited• Bringslimark T, Hartig T, Patil GG. 2007. Psychological benefits of indoor plants in

workplaces: putting experimental results into context. HortScience 42: 581-587.• Brown SK, Sim MR, Abramson MJ, Gray CN. 1994. Concentrations of volatile organic

compounds in indoor air – a review. Indoor Air 4: 123-134.• Burchett M. 2009. Towards improving indoor air quality with pot-plants – a multifactor

investigation. Horticulture Australia Ltd, Sydney.• Chang C-Y, Chen P-K. 2005. Human response to window views and indoor plants in

the workplace. Hortscience 40: 1354-1359.• Fjeld T, Veiersted B, Sandvik L, Riise G, Levy F. 1998. The effect of indoor foliage

plants on health and discomfort symptoms among office workers. Indoor and Built Environment 7: 204-210.

• Han K-T. 2008. Influence of limitedly visible leafy indoor plants on the psychology, behaviour, and health of students at a Junior High School in Taiwan. Environment and Behaviour 41: 658-692.

• Kaplan R, Kaplan S. 1989. The Experience of nature: A Psychological Perspective. Cambridge University Press, Cambridge New York.

• Larsen L, Adams J, Deal B. 1998. Plants in the workplace: the effects of plant density on productivity, attitudes, and perceptions. Environment and Behaviour 30: 261-281.

• Liu Y-J, Mu Y-J, Zhu Y-G, Ding H, Arens N C. 2007. Which ornamental plant species effectively remove benzene from indoor air? Atmospheric Environment 41: 650-654.

Literature Cited• Lphr VI, Pearson-Mims Ch. 2000. Physical discomfort may be reduced in the presence of interior

plants. HortTechnology 10: 53-58.• Lohr VI, Person-Mims CH, Goodwin GK. 1996. Interior plants may improve worker productivity

and reduce stress in a windowless environment. Journal of Environmental Horticulture 14: 97-100.• Maller C, Townsend M, Pryor A, Brown P, St Leger L. 2005. Healthy nature healthy people:

‘contact with nature’ as an upstream health promotion intervention for population. Health Promotion International 21: 45-54.

• Orwell RL, Wood RA, Burchett MD, Tarran J, Torpy F. 2006. The potted-plant microcosm substantially reduces indoor air VOC pollution: II. Laboratory study. Water, Air, and Soil Pollution 177: 59-80.

• Raanaas RK, Evensen KH, Rich D, Sjøstrøm G, Patil G. 2011. Benefits of indoor plants on attention capacity in an office setting. Journal of Environmental Psychology 31: 99-105.

• Rosenstein LD. 1985. Effect of color of the environment on task performance and mood of males and females with high or low scores on the scholastic aptitude test. Perceptual and Motor Skills 60: 550.

• Shibata S, Suzuki N. 2002. Effects of the foliage plants on task performance and mood. Journal of Environmental Psychology 22: 265-272.

• Soldat AS, Sinclair RC, Mark MM. 1997. Color as an environmental processing cue: external affective cues can directly affect processing strategy without affecting mood. Social Cognition 15: 55-71.

Literature Cited

• Solomon SJ, Schade GW, Kuttippurath J, Ladstätter-Weissenmayer A, Burrows JP. 2008. VOC concentrations in an indoor workplace environment of a University building. SAGE Publications, Los Angeles.

• Tarran J, Orwell R, Burchett MD, Wood R, Torpy F. 2002. Quantification of the capacity of indoor plants to remove volatile organic compounds under flow-through conditions. Final Report to Horticulture Australia, Sydney, Australia.

• Tennessen CM, Cimprich B. 1995. Views to nature: effects on attention. Journal of Environmental Psychology 15: 77-85.

• Ulrich RS. 1984. View through window may influence recovery from surgery. Science 224: 420-421.

• Ulrich RS, Dimberg U, Driver BL. 1991a. Phychophysiological indicators of leisure benefits. In: Driver BL, Brown LR, Peterson GL. (eds) Benefits of Leisure. Venture Publishing, State College Pennsylvania.

• Ulrich RS, Simons RF, Losito BD, Fiorito E, Miles MA, Zelson M. 1991b. Stress recovery during exposure to natural and urban environments. Journal of Environmental Psychology 11: 231-248.

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