Dealing with insects in the garden

There are literally hundreds or thousands of different insects that find their way in and through our gardens every year.  Some are there all the time, some just come and go.  Most are harmless to you and your plants and lots are even helpful.  Encouraging them is worth the effort.  Some insects (the pests) are annoying.  Some are destructive and have a significant impact.  Managing them is a challenge.  Regardless, we first have to accept that insects are there (whether we like it or not) and from there we can move to minimizing the impact of the pests.

What follows is a brief and simplified list of some the things that you might consider doing (alone or in combination) to minimize the overall impact of pests, by reducing or preventing infestations and making things less “pest-friendly”.

• Start clean – Insect pests can, and will, arrive under their own power.  Some walk.  Some crawl.  Lots fly.  Others catch a ride.  However, bringing them into your garden seems a bit foolish and is a bit like tempting fate.  It is kind of like saying “They probably won’t like it here”.  Therefore, the strategy is to ensure that any plants that you introduce to your garden are free from insects or other pests.  Give the plants you are buying a good once-over and pick those without any stowaways.  Also, make sure that any plant material that you plant is healthy, so they have a good head start on life. 

•  Know your friends – There are many (a huge number) beneficial insects running, flying or crawling through the garden.  Try to understand what the insects that are present are doing.  Recognize the insects that that aren’t doing any damage or that might be helping out.  Just because it is on the plant, doesn’t mean it is hurting it.  Some good insects may resemble the bad ones, but you can often tell friend from foe using the statement in the Bible that said “Wherefore by their fruits, ye shall know them.”  Watch what they are doing. You’ll see the clues.

• Know (and understand) your foe – Just like knowing your friends is important, you have to be aware of the different pests that can damage your plants (a.k.a. your enemies).  Know that what they and their damage looks like, as well as a bit about their life cycle.  This way, you can know whether you have a problem or not and how best to minimize their impact.  The idea is to know what their Achilles heel is and where to hit them.  By knowing how they move, how they overwinter, how they reproduce, if they need specific hosts, what climatic conditions they prefer, you’ll be better equipped to counter them.

• Encourage rivalries – Once you know friend from foe, you should consider encouraging and/or introducing beneficial insects as a way to manage the problem insects.  You can do this by being judicious in your pesticide applications, planting species that serve as a “home” for the beneficial insects and implement practices that encourage them to stay.  Sometimes you have to sacrifice a bit of quality and a small pest problem to keep your beneficial alive and productive.

·         Exclusion – Some plants can be protected by keeping the pests off.  Essentially, you tolerate them in the neighbourhood, but you don’t let them live on your plants.  It is important to understand the habits and life cycles of the pests you might encounter.  Depending on the pest, you might protect using plant covers, short mesh screens (for those insects that are low flying), barriers around the base of the plants or other means of keeping insects from either feeding on or laying their eggs on or around the host plant.

• Lure and trap the scoundrels – If you can’t beat them in a direct and fair fight, trick them, then destroy them.  Many insects are drawn to plants by detecting the unique chemical “odours” put out by the plants.  Others are drawn by colour or other triggers.  Use this natural habit to your advantage.  Try the following:

o   Putt out trap plants – these plants serve as sacrificial lambs, which you either drop the bomb on or that you remove once they are loaded (or they just load up on the pests, while the plants you actually like pass unscathed.

o   Place sticky traps - these yellow or blue cards are meant for monitoring, but they catch a fair number of pests, as a side benefit.  They are simple, cheap and just need a bit of sticky stuff to be effective.  Their orientation relative to the ground and their height relative to the canopy will determine what you catch.  Change them when they start to fill up.

o   Place baits (liquid or solid) – these are geared to drawing the pests to where you can either remove them or kill them.  Some people use shallow pans of a beverage or maybe a partially buried piece of potato, depending on the pest.  You might need to change or “recharge” them occasionally, if they are popular.

• Remove and destroy – Some pests are big enough or occur in dense enough populations that you can pick them up and remove them (and perhaps the plant part that they are on) easily.  Anything that you can do to interrupt their life cycle and cut down the population, the better off you’ll be.  This method ties in nicely to trap plants or baits.  In lots of cases, you need to go after either eggs, adults, nymphs or other immature stages, such as larvae.  I still remember the Great Potato Beetle Hunt of ’85, where a bounty was offered for adults and larvae in a jar and for crushed egg groups. What I don't remember is being paid...

The overall message is that you can have healthy, good quality plants in your yard and garden.  You just have to take steps to accept, encourage, recognize and exclude and with some mental and physical exertion, you should make out fine.

Plants are just like People ... sort of.

Do you have a green thumb, or aspirations to such?  Do you ever get that sense that you relate better to something inanimate than to Billy Bob, your neighbour (this may depend a bit on who/what Billy Bob is, as well as the size of his truck)?  Or on the flip side, do you find the mysteries of the Plant Kingdoms beyond you?  Never fear.  Whether the world of photosynthetically-active green “people” calls or repels you, there is hope.  The two sides aren’t that different, at all.

Most of us humans have a reasonable understanding about what we need to live and thrive.  Plants are very much the same.  Meet the basic needs and you are good to go.  As a horticulturist, I am strongly inclined to explain things in terms of what plants do and how they act and react, sliding dangerously across the line that divides plant appreciation and the feeling that plants are live and interactive.

Regardless, please allow me to outline how plants and humans aren’t all that different.  For the plant-lovers, you’ll recognize the truth and maybe appreciate humans a bit more.  For those that don’t “get” plants, maybe you’ll gain a better appreciation and understanding about what makes those plants tick.  A few more plants will live and we’ll be the better for it.

Basic Needs:

In Mosby’s Medical Dictionary (8^th Edition – 2009), it defines the basic needs of humans as “the elements required for survival and normal mental and physical health, such as food, water, shelter, protection from environmental threats, and love.”  Without these things, humans can’t survive.  Indeed, in times of crisis, we work hard to restore a supply of the basics, before trying to get things entirely back to normal.

True to form, plants are really no different.  Plants need sunlight, air, water, nourishment, adequate temperatures and freedom from pests.  Let’s delve into each, since we want to learn more about how plants and humans are similar.

Light:

The fundamental function of plants is to capture and harness the energy the sun’s rays, converting it into products such as sugars, through processes that take in carbon dioxide (CO₂), water (H₂O) and other elements and releasing oxygen (O₂).  Without light, plants can’t capture the energy they need, create the food they (and others in the food chain) need and we start running a bit low on oxygen.

In the absence of light, or when light gets low, plants tend to be light-coloured or pale, even whitish.  Growth is weak, plants become stretched and spindly.  Over time, they diminish and eventually fall prey to illness or just die from starvation (essentially). 

Now, the non-plant people may be thinking, “We aren’t plants.  We don’t need sunlight to survive.  Why bother to even bring it up?”  You are partly correct.  However, I think that a good argument can be made that we do need sunlight to be healthy AND happy.  When we don’t get enough sunlight (and we need the sun to get Vitamin D – other than through supplements), we aren’t healthy.  Picture that weird cousin (you know the one) that never leaves the basement or house.  We become pale and anemic, pasty and weird (debatable).

The medical community now recognizes a disorder known as Seasonal Affective Disorder (SAD), which results in lack of energy, fatigue and depression, with typically “normal” activity in summertime.  SAD is also known as winter sickness, seasonal depression, winter blues, etc.  The basic treatment for SAD is simple: Sunlight.

People and plants that get too much sun have a similar reaction.  They experience tissue damage and don’t function properly for some time (remember how much it hurts to move with a lobster-esque sunburn).

Air:

We all need air to breathe.  Specifically, humans need oxygen.  Plants need air, specifically CO₂.  At higher levels of CO2, plants really thrive, because they become more efficient.  In conditions without any oxygen (anaerobic), both humans and plants don’t thrive.  They die.  Similarly, both plants and humans do poorly when air becomes stale and stagnant or polluted.  A bit of air movement and replacement of the air goes a long way to a healthy life for both of us.

Water:

Humans need water to stay alive.  We also use it to wash (ourselves and other things in our lives) and to stay cool and refreshed.  We are hydrated organisms.  So are plants.  Plants are comprised of up to 90+ per cent water.  Plants need water to maintain their cellular structure, for their physiological processes and reactions and to move elements things around within the plant.  Plants need a constant supply of water to stay hydrated and react very strongly to changes in both the soil moisture content and the relative humidity of the surrounding air.  Plants don’t sweat but they do make adjustments to ensure that there is fluid moving through them at the appropriate rate.  Plants can be protected from overheating and from freezing by the application of water.  Water is necessary to wash off the plant or plant parts, certainly after harvest.

If humans or plants are exposed to too much or too little water, they don’t do well.

Nourishment:

Whereas plants can produce their own “food products” from the sun, air and water and mineral elements in the soil, humans have to consume their nutrients (from plants or other animals).  Regardless, the need for food or nourishment is consistent between humans and plants.  When we think of food or nourishment for plants, we think more in terms of the supply of mineral elements (such as nitrogen, phosphorus, potassium).  Plants that are supplied with enough nutrients are healthy and productive, grow at a good pace and are more resistant to attack from disease or pests. 

Undernourished plants are weak, off-coloured and unproductive and may die.  Plants that get too much nutrition become unhealthy, in that they grow rapidly and weakly, often becoming soft and lush or tender and often sicken more quickly.  They can produce less fruit (and more leaves) and may “forget” to shut down for the winter.  Most of those descriptions sound a lot like what happens to over or under-fed humans.

Protection from the elements:

Humans need shelter.  This represents a protection from temperature extremes and other weather elements.  Plants need to be protected from these same things.  Plants (just like people) grow better at different temperatures, typically not the extreme ones.  If it gets below freezing (or even just colder), humans put on layers of clothing or go inside their homes.  Plants adjust somewhat, but then will eventually die.  The use of greenhouses, cold frames, or other plant covers (essentially “plant clothing”) are all that we can do to give plants a break from the colder elements.  Shading or misting is necessary to cool off plants when things heat up.

Space:

Humans need their personal space (some people forget this) and certainly do not thrive when they are packed like sardines into any particular space for an extended period of time.  Plants are no different.  Whereas the initial affect that many humans experience is probably more psychological than physical, plant overcrowding result in direct completion for limited resources.  Plants that have (too) close neighbours will be weakened or may be literally choked out (think of weeds).  The stagnant air that can develop will result in an increase in disease or other issues.

Plants that lack competition thrive to a certain extent, but also become a bit overgrown and wild.  Humans that lack contact with others become a bit wild or anti-social.

Freedom from pests:

No one likes to be sick, whether you are human or green.  We all suffer from various ailments and attack from different pests.  Humans take medicines.  We treat plants with “medicines” to try and fight off attack.  Both species become a little stronger if we are attacked in limited degrees.  But in general, we need to be free from pests or disease if we are going to thrive.

Love:

The original definition of basic human needs included a need for love.  It is interesting, but certainly not all that surprising.  We thrive on relationships, or are at least healthier contributors to society (remember your weird cousin?).  Are plants that different in this need for companionship or relationship?  They rely on us for a supply of nutrients, water and support (physical).  We protect them from the elements, from excessive competition and provide a bit of grooming.  Some might consider it a utilitarian and emotionless relationship, but anyone that has shed a tear after a frost or a big wind, knows that there is more to it.

Conclusion:

When you lay it out, it isn’t hard to see the similarities between humans and our green friends.  We both need some basic elements to survive and to really thrive.  The only thing that is maybe a bit different is that plants need to grow in soil (to supply structure/support and nutrients and water).  Humans don’t necessarily need dirt between our toes, do they?

Horticulture – Origins and Impact

According to the dictionary, the word horticulture comes from the Latin words hortus (garden) and cultura (to grow).  Horticulture is further defined as “the cultivation of a garden, orchard, or nursery; the cultivation of flowers, fruits, vegetables or ornamental plants” or “the science and art of cultivating such plants”.  Within horticulture, you’ll find the areas of edible crops (i.e. fruits, vegetables, potatoes), medicinal, herb and spice crops, as well as ornamental crops, such as trees, shrubs, turfgrass, sod and golf course, cut and potted flowers and bedding plants.  Plants are grown indoors and outdoors, in the soil, in pots or containers or in other areas.  You’ll also find a host of assembly, support or maintenance industries, including landscapers, landscape architects and designers, lawn care professionals, arborist, horticultural therapists and the list goes on.

Most of the time, when you mention or indicate an interest in horticulture, you are greeted with a blank stare or a hearty “huh?”  I suspect that most of the confusion comes from a lack of understanding of the term, rather than a true lack of comprehension.  That being said, most people are unaware of the millions of impact points of horticulture in their daily lives.

Take a walk with me through an average day and see how you are “touched” by horticulture.  Maybe you’ll feel a little more horticultural at the end of it.

You wake up and hear the rustle of leaves on the trees outside in your yard or on the boulevard. Maybe you hear the whir or rumble of the neighbour’s lawnmower or the smell of fresh mown grass.  You prepare a healthy breakfast, complete with orange juice, cereal or pancakes topped with fresh berries or toast with jam.  Splurge and have an omelette with sweet bell peppers and chives or green onions. 

As you head to work, you pass a green space, rows of trees, decorated flower beds and hanging baskets.  Your lunch has carrot sticks or a mixed garden salad.  The atrium in your building is full of tropical plants.  You bail out early to hit the links with some friends, enjoying the tightly mown, immaculate greens and shady trees lining the fairway.  You pick up a potted plant or a bouquet of fresh cut flowers to decorate the table at home.  You head out in the yard after dinner and weed the vegetable garden and flower beds.  And you relax.  Calmness ensues.

And that is just one stereotypical day.  Horticulture has significant references throughout history.  More recently, horticulture represents multi-billion dollar industries.  Gardening is one of the top pass times or hobbies in the world.  So many of the commonplace activities or events in our daily lives are influenced by horticulture, it really is amazing.  The next time you have a chance, hug a horticulturist.  We matter.