

THE GREEN SPOT 



To Screen or Not to Screen... 



That Is the question — especially If you're devel- 

 oping a pest management plan for a green- 

 house. To answer that question, take a look around 

 the building site to determine what flora and 

 fauna exist and remember this: screens will keep 

 most bugs out, but will also keep most bugs In. 



The Urban Jungle — concrete for as far as the eye 

 can see. The only pests likely to enter the green- 

 house are the ones which are already on the plant 

 material. The Influx of site-borne pests — and 

 beneflclals — will probably be very limited. Screens 

 might be a good Idea, but only If pest-rldden 

 plants can be Identified and culled out prior to in- 

 stalling them In the main structure. A holding 

 house should be at the ready. 



The Farm Land — cornfields and grasslands 

 abound. Both are magnets for both beneflclals and 

 pests. Screening will probably be a must. Left 

 alone, the surrounding area should create a nice, 

 healthy diversity. Mid- to late-season harvesting of 

 surrounding areas, though, may create havoc. There 

 are enough thrlps trying to get into a greenhouse 

 at year's end as It is. Clear-cut their harborage 

 and they're likely to swarm In and the beneflclals 

 are apt to not follow and you'll be stuck with a 

 terrible Imbalance. 



The Back Woods — old growth, new growth, lots 

 of growth, lots of diversity. This Is probably a 

 good candidate for an open-system, no-screen 

 greenhouse. Pests and beneflclals will make cameo 

 appearances all season long and should keep 

 themselves In check. As with any situation, proper 



scouting and record-keeping. In addition to proper 

 spot treatments, should provide trouble-free grow- 

 ing without screening. Just remember that ail bugs 

 aren't bad and that Mother Nature Is capable of 

 keeping things In line, so don't freak out every 

 time a critter Is spotted. 



Screens can reduce air circulation and hamper 

 cooling; they can contribute to the growth of dis- 

 eases, trap pests in with the plants, kill intro- 

 duced beneflclals trying to come and go, exclude 

 native beneflclals trying to get In to help. Screens 

 can Isolate your problems and successes, but can 

 also put you at odds with nature. 



The lack of screens can allow nature to work 

 with you, but in the wrong area, can leave you 

 open to nature's wrath. 



Consider screening only In late summer and 

 fall — when pests are looking for an overwintering 

 refuge. But before you go ahead, look around to 

 see what kind of area you're in and what your 

 goals will be. If bugs cannot be tolerated: screen. 

 And while you're at it (so the |ob Is done right), 

 consider pouring a concrete floor. Installing door- 

 way blowers, and having a quarantine greenhouse 

 situated on-site. 



Be warned though, that if you're going to battle 

 nature, you may want to grow the less Inviting 

 plastic plants instead. 



Mike Cherim, president of the Green Spot, Department 

 of Bio-\ngenuity, 93 Priest Road, Nottingham, NH 

 03290-6204, can be reached at 603-942-8925. 



PRUNERS 



SPRAYING ACCESSORIES- 



OESCO, INC. • PO Box 540 • Rte. 116 • Conway, MA 01341 

 800-634-5557 • 413-369-4335 • FAX 413-369-4431 • www.oescoinc.com • email:info@oescoinc.com 



12 



THE PLANTSMAN 



