Finally caught the culprits eating my peas!
This is an 8 year story, so bear with me.
For YEARS I have been frustrated because SOMETHING has been gobbling my pea plants so badly I can hardly get a single pod. The first year or two after I started my garden here in Fort Collins I had decent luck with peas. But by the third year my plants were stunted, struggling and raggedy looking. A year or two later I realized it wasn't that the plants were unhealthy, the problem was they were being EATEN! Particularly when they were small, I could see that something was nibbling on the growing tips, tendrils and the newest tender leaves, chewing them all off. Some of the leaves had little 25 or 30 degree angle chunks torn out of them. Instead of round leaves, my pea leaves were just nubbins, or chewed to the ground, or you could see they had several of these little 25 degree triangles ripped out.
Well, that made sense. I knew the reason peas are resistant to frost is because there's a lot of sugar in their blood. I also had seen mice in the garden a number of times, so my first suspect was the mice. So that winter, and the following spring, I put out mouse bait, and made sure to keep it filled to kill off the mouse population. The result that year was no change. So the next year, I continued the poison, and beefed up my efforts with a couple of those metal box type traps. Still no change
I knew we've had a little trouble with rats in the neighborhood occasionally. I suspect they're partial to the irrigation ditch, since I know several people with yards next to the ditch have had to deal with them. Now I suspected Rats. The next year, in addition to the poison, and the traps, I sprinkled really hot chili powder solution on the young pea plants. Rats are SMART. (usually smart enough to not eat wayfarin) I figured if they get that powder a time or two, they will want nothing to do with my garden or my peas after that. The chili seemed to have some effect, but since my sprinklers go every 3rd night washing away the Chili powder, after about 2 weeks, I realized it would cost me a LOT in Chili powder to keep my peas healthy. So I quit the Chili powder, and within a week, once again my pea plants were raggedy and decimated. The weird thing is, I kept looking on the ground for some sign of the culprits. I looked for rat prints, or squirrel prints, or raccoon or rabbit prints in the mud, or poop on my carpet scrap mulch between rows. But there were no signs of such a critter.
This year I was BOUND and DETERMINED to keep mice, rats, squirrels, raccoons and all other sorts of vermin out of my peas. I bought several big rolls of hardware cloth at home depot, for each of my usual 3 rows of peas, I folded the hardware cloth into long triangular Teepees about 12 inches tall to cover the entire row. I dug furrows for the sides and buried the edges of these covers a good 3 or 4 inches to insure mice wouldn't have much luck if they tried to dig under my protective covers. I watched carefully to make sure nothing was trying to dig under there. Sure enough, the little pea plants took off like rockets inside the Teepees. For the first time in years they were strong and healthy and growing FAST. I figured that once the plants had good momentum and decent size, they could either grow out through the hardware cloth, or I could just remove the teepees entirely. But as soon as they reached the hardware cloth and started to send growing tips or baby leaves out through the holes, I could see once again they were getting chewed off as soon as they stuck out past the holes. Still no footprints or signs of critters.
Since apparently anything exiting my Teepees was getting chewed off, I waited until it seemed like my plants were all very strong and vibrant. Then I removed the teepees. I figured, surely a few mice or a couple of rats or squirrels couldn't possibly eat 3 whole rows of strong pea plants already 12 or 14 inches tall and growing fast. So I removed the teepees. It worked! Once again, I could see they were being eaten. More than I expected, but at least my plants were already big enough they were not decimated. I was surprised to find the plants were getting chewed up even more at the top than near the bottom. Why would a mouse or rat climb up to the top of my little wire fences to eat pea plants rather than just chomping away in safety near the ground? Again, the pattern of little triangles torn out of leaves, and now with the plants much bigger and healthier the pattern was more obvious, since the critters weren't able to chaw the plants nearly to the ground.
Then, it happened. One day, I was sitting on my deck drinking a beer, when out of the corner of my eye I caught some kind of motion down in the garden. I never wear my glasses at home, and my eyes aren't what they used to be, so I couldn't tell what it was, but there was definitely something moving in the peas. I grabbed my binoculars, and then I SAW THEM! FINCHES!!! 10 or 20 of them. Little red and brown house finches! They were GOBBLING my pea plants! I knew right away, it HAD to be them. It must have been the finches ALL Along. On closer inspection, I now noticed little bird droppings on the leaves, and I realized the little triangular shaped rips on the leaves must be from the triangular shape of the beak of the finches.
Within an hour I had one of those fine black bird net things intended for a fruit tree, covering all 3 rows of peas. Sure enough, now my peas took off and grew gangbusters, right up until they tried to poke out through the top of the net, where the finches could get them. The net meant my daughter and I had to crawl under the net between the rows to pick the peas, but this year we got a bumper crop of peas. Sugar snap, Japanese pod peas, and regular old garden peas, they all did well.
All those years, I guess those little guys are shy enough they would always fly away before I could get close enough to the garden to see them without my glasses. I've heard birds can have collective memory about food sources, I guess the first year or two of my garden, they were just discovering this new food source. Well now that the mystery has been solved, next year I'm planning to put up some kind of a hoop house to hold the bird netting up high enough over the pea patch so that I can walk upright to get in there to pick and weed. (Since I won't be needing them next year, I've recycled my hardware cloth teepees and made gutter protectors out of them to keep the leaves from clogging my gutters)
I hope maybe my long story will help someone else have a little success with peas in less than the 8 years it's taken me to solve this puzzle.