Seed beds can have the covers put right on the soil. The covers keep moisture in the ground, keep soil temps steady and keep driving spring rains from turning a fluffy seed bed into something resembling concrete. This greatly aids in germination.

Most plants don't like the weight of covers on them so it is advisable to use hoops. We put up hoops as soon as we notice seeds have germinated . We put up hoops over all transplanted seedlings that will be getting covers. The length to cut the material depends on the width of your beds and the height of the plants to be covered. For wire I use 8' lengths for 4' wide beds and 2' high hoops. PVC and Conduit come in 10' lengths so that is the usual length used for those materials. Hoops are very important for season extension as plants touching row cover in cold weather will get frost damage.

Here is a list of equipment that can be used for row covers.

• Wire
  I use #9 gauge wire which can be bought in bulk at any farm supply store. These are thin and tend to fall over in very wet conditions but they are cheap and don't leach chemicals into the soil.
• PVC Pipe
  PVC needs to be anchored with rebar. It is wider than wire and doesn't damage the covers as much because of the width of the pipe. They are also less likely to fall over. PVC can leach chemicals into the soil though, is tough to dispose of and might cause chemical reaction with UV stable plastics. It is not UV stable so it will degrade in 2 or 3 years. It is not structurally strong. PVC needs to be used with rebar anchors.
• Metal Conduit
  Conduit is sturdy and long lasting but initial cost is more than PVC (though over 10 years costs become cheaper than PVC). It is not reactive with any plastic. Conduit needs to be used with rebar anchors.

Anchoring the Covers

• Bricks and Rocks
  Bricks or large rocks (5 to 10lbs) should be spaced every 3' or so. If there are big winds (25 mph+) I space the rocks every foot. The big advantage is that they are cheap and usually plentiful.
• Fence Stakes
  Fencing stakes are heavy and long and do a decent job of keeping covers in place but they tend to rip the cover. They're heavy and sometimes hard to move.
• Soil
  Soil is used by digging a shallow trench and burying the edges of the covers. This does a great job of holding covers in place but it is hard to move covers for maintenance and harvesting.
• Spring Clamps and Clothes Pins
  Works decently but spring clamps are expensive and covers tend to rip where clamped. Use spring clamps with PVC or Conduit and clothes pins with wire.
• Staples
  Staples are U shaped wire you stick in the ground to anchor covers. These tend to be pricey if premade but you can make your own with #9 wire. Some folks love these things and other hate them.

When to Use Row Cover

Summer Use For Insect and Weather Protection

Covers can stay on plants the entire summer. The covers keep drying winds off of the plants, keep moisture in the soil and keep the median temp at around 80°F to 85°F. A 2003 study by a Spanish group of researchers found that crop quality and yields were better under covers than plants exposed to the elements. We have found that some crops do not do well under row cover at all. Green beans tend to get too leggy even under the lightest weight covers and than fall over when full of beans. We do not use cover on beans other than for germination. Other crops such as lettuce, squash, peppers and brassicas thrive under cover.

Most flowering plants need pollination and the covers should be removed about a week before the female flowers bloom so the pollinators can find them. The problem here is if you leave the covers off for more than a day the insects you were excluding will find the plants and set up housekeeping. When the covers go back on you will have a far worse problem than leaving the covers off for the remainder of the season. Either leave the covers on and hand pollinate or remove them permentantly.

Row covers go on as soon as the seed or seedling is planted. Be ready by having all materials (hoops & anchors) with you when transplanting so that it is easy to apply the covers as soon as possible.

Row covers work by excluding and camouflaging the plants from insects. The row covers are white, not green, so many bugs do not recognize that there is a food source around, even if the cover has holes in it. That said, some insects, especially aphids, flea beetles, cucumber beetles and European bean beetles can find their way into holey covers. A cover in good condition that is well anchored will exclude almost all insects except those that are already in the soil and emerge under the covers. We have had this happen with Japanese beetles this season. They mysteriously appear under the covers. This is why one must check under the row covers regularly

Season Extension

For season extension the covers need not be removed except for maintenance and harvest. They need to be put on before the freezing weather arrives. They have to be be well anchored so that high winds do not remove them and kill or damage your crops

Row covers work great in conjunction with unheated hoophouses. Every layer over the plants means a higher (warmer) growing zone. So if you live in zone 5 and put a heavy cover on your plants you have taken them to zone 6. If you put a hoophouse over that you have taken them to a zone 7 environment.

Row covers do not work well in heavy snow areas. The snow tends to mash down the hoops, leaving the covers flat on the ground. This does not usually hurt the plants in any way (snow makes a wonderful insulating mulch) but it is impossible to remove the covers for harvest without destroying the covers and possibly the plants.

Problems with Row Covers

There is a learning curve with Row covers. They are not easy to use at first but with time they become indispensable. Still, they are not perfect.

Insects Most pest insects love the row cover environment and can decimate a crop quickly. For flea beetles and other pests I use a container filled with water and covered with Tanglefoot to control them. The water warms up during the day and at night the bugs are attracted to the heat and get stuck. I have tried introducing beneficial insects with limited success. Ground spiders seem to be very attracted to row covers and do keep some pests under control. Any pest insect caught under a cover can become a problem quickly so it is good to check for them often, at least every other day. We have tried vacuuming insects from under covers with fair success. We used both a hand vac and the vacuum on our 8 hp chipper shredder.

Anchoring If row covers are not anchored well they tend to blow away or they come partially loose and whack the crop they are suppose to be protecting. In a worse case scenario the row cover will get ripped up. Anchoring is the hardest thing to learn, in my opinion. The covers need to be applied squarely and be pulled tight from end to end to stay on well in high winds. This can be done with one person but two makes the job a lot easier and more effective

Animals will punch holes in them, especially if they are on hoops. We have had cats that love to jump into them and form large holes. Deer will also walk and run through them once they get use to them, leaving holes behind.

Disposal They are made out of plastic and hard to dispose of ecologically. The exception here are the cotton row covers which can be composted. There are companies that will recycle plastic row covers and irrigation tape in some parts of the country.

Out of sight, out of mind. It is easy to not check plantings under row cover as often as one should. Both weeds and insects can get out of control. Simply setting up a schedule for looking under the covers solves this.

Row covers are an essential on our farm for insect and weather protection, as a germination aid, season extension and improvement in crop quality and yields.

Web Resources

Sources for Row Cover

Nolt's Produce Supply
152 N. Hershey Ave
Leola, PA 17540
(717) 656-9764
(Amish company, no website)