The summer months bring sunshine, happiness, escapades and mirth!  But it’s also a time of high risk!  Insects are in abundance and they want to find their way to your indoor plants! We asked our main man Zorro Torro to explain how the war on pests is won through a series of simple preventative methods. Mr Torro, the stage is all yours…

Plant pests and indoor gardens do not mix. The environmental checks and balances that are natural controls out of doors—i.e. weather and predators—are not factors indoors. The indoor garden presents a veritable Garden of Eden to the pest that gains entry. Abundant food, good weather conditions and lack of predators allow them the opportunity to enjoy their two favorite pursuits: eat or suck on plants, and reproduce. Over millions of years they have been self-selecting and are excellent at both activities.

You may remember school graphs and factoids regarding unrestricted reproduction of rabbits: an exponential increase in population could result in one year. Mites and insects have a much faster maturation cycle and produce many more eggs or young than rabbits. In just a few generations, produced in two months or less, a tiny infestation becomes a life-threatening attack on a garden.

There is no stabilization that occurs in nature: in this uneasy equilibrium, pests, plants and predators reach a balance that generates a minimal loss of crop. Indoors, however, the optimum conditions leave their population growth unchecked, bringing plants under siege.

It is for this reason that I firmly believe in a zero tolerance policy for garden pests. (I should probably practice this policy in life too, to eliminate many unnecessary disturbances.) This means that no pests are allowed in the garden. You may have read elsewhere that once your garden is infested it is impossible to eliminate pests. This is wrong. Pests can be eliminated, but it’s a far better idea to keep the growing space pest free in the first place.

Let’s say you purchased some meat that was infested with vermin. You would consider it inedible. Then why would you tolerate eating infested vegetables? Prevention is less costly than cure in material, labor, and injury to the patients—so it is wise to integrate preventative designs and practices for the garden while it is being constructed. If the garden is already in operation it should be retrofitted for prevention.

In 1668 Francesco Redi proved that spontaneous generation was a myth. By covering one jar of meat and not another he showed that maggots did not just appear; they were the result of eggs flies laid in the meat. Organisms don’t just suddenly appear. All pests found in an indoor garden originated somewhere else. Once they wend their way into the garden they find the Promised Land— free food, no species competition, no predators, and a comfortable climate.

There are only a few ways that insects can enter an indoor garden. Blocking their access is the best way to practice preventative medicine and deter plant damage.

THE EASIEST PEST IMMIGRATION ROUTES

• Piggyback a ride on humans.
• Piggyback a ride on pets.
• Ride in on outdoor garden tools.
• Arrive with un-sterile or un-pasteurized soil or planting mix.
• Immigrate with newly acquired plants or clones.
• Fly in through an unfiltered air intake pipe or an open window.
• Crawl in through cracks and holes.

PIGGYBACK A RIDE ON HUMANS

Gardeners should be careful to wear uncontaminated clothing, which can carry pests from outside into the garden.

Insects can catch a ride on humans. When we are outdoors we come in contact with nature. Grass, bushes and trees are all hosts to pests that want to colonize your garden. Mites and aphids are the most likely culprits, but small caterpillars, thrips, fungus gnats and whiteflies also use this route of entry.

All clothing that has had even casual contact with outdoor plants should be considered contaminated. Ninety-nine percent of the time this isn’t true. It is that one bad apple out of 100 that you are worried about. You step on some grass in the crack of the sidewalk and a mite hitches a ride on your footwear. You walk under a tree in the parking lot and a thrips drops on your hat or hair. A pregnant aphid catches on the fiber of your jacket.

PIGGYBACK A RIDE ON PETS

Pets are naturally curious, but should be kept out of the garden because they could be carrying a plant pest.

Pets are worse pest carriers than humans. Fur and bare feet provide good hiding places for the ride into the Promised Land. Pests use dog and cat ears, tails and bellies as handy saddles.

There is just no reason to allow a pet into the garden area. They can provide no useful service to the garden and their presence is harmful. Pets can carry an infection into the garden and transfer it by brushing up against a plant. Their fur is also a problem as it constantly shedding, along with dander particles, which then float in the air with any breeze or air circulation in the garden.

RIDE IN ON GARDEN TOOLS

Outdoor gardens are a hotbed of activity when you get down to the small level. Ants, beetles, and other creatures are scurrying about. Aphids, scale and mites are contentedly sucking plant juices. Whiteflies, gnats and leafhoppers go airborne in their pursuit of vegetation. Underground there is even more activity. Thrips and fungus gnat pupae are maturing for their above ground debut, while fungi, molds and all kinds of micro-life are playing their bit parts in the ecological cycle.

Tools should be cleaned before they are used in the indoor garden to ensure no outside pests are hitching a ride.

Just as plant pests may hitch a ride on you, they can take trips on your tools. All it takes one mite or aphid hiding on a clipper or some thrips pupae or infectious agents on a hand hoe. For this reason tools should not be returned to the indoor garden space after being taken outdoors. Only after the tool is thoroughly washed with no visible plant parts or debris may it be returned to the indoor garden.

IMMIGRATE IN SOIL OR PLANTING MIX

Most planting mixes are composed of either bark or peat moss and other ingredients such as compost, puffed minerals, sand and nutrients. The ingredients have never been in contact with plants or plant pests so they are free of contamination.

Pasteurized or sterilized soils and planting mixes are free of pests and infections. Although soil is not currently a popular medium, a high quality loam can invigorate plant growth when it is included in planting mixes. Pasteurized and sterilized soils are the only ones to use.

Importing unpasteurized planting mixes that contain soil, landscape mixes, or used soil or planting mix can be risky. They all contain a host of microorganisms that may be beneficial but they also may contain insects, their eggs, and other soil dwelling pest and disease organisms. Landscape mixes are not meant for indoor use. Outdoors, the natural balance of nature rules, so insects and other organisms are in a wavy equilibrium. Indoors, these creatures are not subject to natural controls such as weather and predators. When contaminated planting mediums are used indoors the pests they harbor will soon make themselves at home and raise large families—and you know the kids are always hungry.

New plants, even from commercial nurseries, should be quarantined before they are brought into the garden.

IMMIGRATE WITH NEWLY ACQUIRED PLANTS OR PLANTLETS

If you were a plant pest, what would be the most convenient way for you to travel? Hitch a ride on a plant that’s about to go on a journey! All plants imported into the garden should be suspected of harboring pests. Plants from hobbyist gardens, houseplants and outdoor plants are most likely to be infected. Plants from commercial nurseries are supposedly grown in sterile conditions so there is probably less chance of infection from them. Even so, they should be handled with care.

To keep your garden pest and disease free, all incoming plants should go through proper immigration procedures. First, they should be visually inspected. If they show any signs of infection the choice should be made. Are these plants so valuable that they should be disinfected? Even if no pests or infections are apparent there may be problems. For instance, mite, thrips and white fly eggs are hard to find and may be overlooked. They will hatch in three or four days and become apparent.

Using a photo loupe or magnifying glass you get a much clearer look at what’s happening close-up. Any eggs or pests become sharply defined. What were little dots become fearsome creatures with legs, crawling around, messing with your plants.

Quarantine Rules

• New plants should be kept in a totally separate garden area from any clean garden plants. The spaces should be kept as far apart as possible.
• New plants should be cared for only after other gardens are serviced.
• New plants should never be placed with other plants until they are fully certified disease-free.
• New plants should be checked daily. Both telltale marks left by the pest and the pest itself are used as indicators.

FLY IN THROUGH AN UNFILTERED AIR INTAKE PIPE OR OPEN WINDOW

I recently saw an ad for a “travel blind” vacation. You sign up for a tropical weekend and they don’t tell you where you’re going until you get there. Insects travel a lot like that. We’ve discussed how they can hitch rides on people and things. However, they can also become airborne. Swept up by the wind, they travel on air currents. It’s a risky proposition for them and many are lost to inhospitable environments where they drown, roast or starve to death. However, insect survival theory takes the losses into account. Thousands may be lost, but one successful colonization may result in hundreds of thousands or millions of progeny. It’s a risk reward ratio that has helped insects be successful for hundreds of millions of years.

Here’s where the theory literally hits the fan. Gardens are often ventilated using air from outside. On breezy days anything can be caught in a wind current. Even on calm days some pest may be flying around and get sucked into the vortex created by the air intake. The solution is simple. Place filters over all intake tubing. Not only will it protect the garden from pests, but also from dust, dander and fur. Nobody likes to see lint on his or her veggies.

I live in a part of the country that stays mild all year. During the warmest months an open window or door usually suffices to adjust the house temperature. Needless to say, my houseplants are constantly getting infected with scale, aphid and mealy bug infections. Between the breezes and the people walking in and out there’s ample opportunity for pests to get to the plants.

In a serious indoor production garden there can never be an open window. All windows must be kept shut. All air that comes in from outside, whether from under the house, through tubing in the window, or any other outside location must be filtered before it enters the room.

CRAWL IN THROUGH CRACKS AND OTHER OPENINGS

Yards are often a source of infection. Insects that hang out in host plants are only a few feet away from Paradise. If there is vegetation next to the building or house you might wish to change the landscaping. Cover the yard in used commercial carpet, installed upside down. The carpet stops all light from reaching the ground and prevents plants from reaching the light. Cover this with gravel stone or decorative mulch. With no plants growing there’s less chance of herbivore pests hanging out in the back yard. The carpet is thick enough to stop plants from growing through it, but it lets the rain soak through. It is free, and available outside any carpet store. It is convenient to use when cut into three-foot wide strips

Secure the perimeter of the indoor space. Using foam caulking, every crack and crevice should be sealed. Before sealing, place a mixture of 50% each boric acid and cinnamon in the cracks using a small spoon. Boric acid is toxic to many insects if they ingest it. When they touch it, granules stick to the exoskeleton. They lick it off and burn out, inside first. Cinnamon is toxic and repulsive to ants. When the mixture is placed in the crevices it signals to pests, “Don’t crawl here.” Make sure there are no open cracks. Even the cracks in the floors should be sealed to make it extremely difficult for insects to crawl through.

By preventing pests from gaining access to your garden, you won’t have to try to eliminate them later. The old adage proves true: an ounce of prevention is worth a pound of pesticide…