What You Will Need:
- Institution-size food cans. In our area the local pizza parlor leaves them at their back door and are free for the taking
- Milk jugs, one gallon size
- Pair of old scissors (I think the plastic would ruin a good pair, but use your own judgement)
Remove the bottom of the can. The top will already have been removed from whoever you got it from, of course, and it will most likely be clean. You end up with a short fat tube, open on both ends. Place this tube around your newly planted seed, and push it down into the soil an inch or two. . OR plant the seed let it sprout, then plan on covering it. Either way works.
Next take a milk jug and poke holes in it around the top and sides (a screwdriver heated over the flame on your kitchen stove works great). Remove the bottom of the milk jug so you are left with the top, straight sides, and no bottom. Now, using those old scissors again, cut a slit at two or more of the corners of the jug so it will fit over the outside of the can. It needs to be snug enough so the wind or watering will not knock it off, so don't cut too deep at first go. Take your time and keep checking the fit until you get it just right.
Do NOT leave the cap on. You want to give your seedlings protection, but they will need good air flow, too. If you leave the cap on you will cook your little plants when they sprout. Take the milk jug portion back off and water your newly planted seed thoroughly. Check on it every few days to make sure it doesn't dry out.
Leave this contraption on your plants until the seed has sprouted and grown large enough that the can/jug combo becomes too small, and you see the plant will soon be growing out of the top. By the time the plants are filling up your can/jug they should be past that tasty stage the bugs like so well and they can be removed.
It isn't pretty, but it works very well.