I have been asked a number of times about Plastic Gourds and my take on them.
Yes, I am a big proponent of Natural Gourds, but I also know that they take a lot of time. First they have to be grown/purchased and then they have to be prepared. And of course, there's always the upkeep. Even a good paint job still needs refreshing every couple of years. If someone has a lot of time on their hands, then all is fine and good. And yes, purple martins love them, as long as they're big enough. Small gourds are small gourds regardless of natural or plastic and I totally disagree with those. If a gourd, plastic or natural, is under 8" in diameter, I won't even give them a second look.
But in the last couple of decades, the new plastic gourds have hit the market. If you don't want to go thru the trouble of finding, preparing and the upkeep on the naturals, then these are definitely a good alternative. YES, I use them. In fact, 3/4 of the gourds I have in my colony are plastic.
Now, first of all, there are a LOT of different kinds on the market, (again, some which I wouldn't give a second look at) so let's break a couple of them down and I'll give you my take on them.
FIRST...let me say this one thing. PLASTIC GOURDS ARE SLIPPERY, therefore; ALL plastic gourds should have a layer of nesting material added to them BEFORE putting them into use. A small handful of pine straw or wheat straw added to the gourd will give the martins a good base for footing and of course, a base to build their nest from. Many folks have bought the plastics and then said that the martins didn't like them. In the majority of the time, it wasn't because they were plastic, but because of the slippery footing. BUT, if a small handful of nesting material is added, then they immediately accept them. I found this out early on when I first tried a few of them.
So, here's my take on a few of the plastics that are available on the market. Yes, there are many more than what I mention here, but these are the ones that I'm familiar with and have actually tried them out in my own colony.
This was the first plastic gourd that came on the market (that I know of). Designed by James Hill III, it is a blow molded gourd that mimics a natural gourd. It comes with an screw on cap for the inspection port making it easy to do nest checks/maintenance. However, (as far as I know) it only comes with one entrance hole style, round or crescent, actually cut right into the gourd, thus, if you want to change hole styles, you have to purchase an entirely new gourd. And, it's well known that if the crescent entrances are used, then porches, both inside and out, are required. Thus, if you want to use the crescent style entrance, then you have to purchase the porches extra. Yes, it's a good gourd, but personally, I think it's a little on the pricey side.
The Troyer Horizontal Gourd
Andrew Troyer had done a world of good for purple martins. Being Amish, he doesn't have a webpage. He's come up with all kinds of good ideas that enable the landlords to more easily tend their martins. Likewise, he invented the Troyer Horizontal Gourd. When he first came out with these, I got a dozen of them. Yes, I still have them today and yes, I think they are a very good gourd, and yes, so do my martins. In fact, these are some of the first ones chosen each spring. They are nothing more that a horizontal version of the vertical gourd and the martins enter from the end of the neck. Their 13 1/2" depth gives the martins a very roomy space to nest and it also comes with an inspection port as well. In fact, ANY GOOD gourds now have inspection ports molded right into them. I would NEVER buy any gourd that I couldn't easily inspect the insides of. When they first came out, there was an issue about being so slippery that martins couldn't get back out of them once they entered, but I gave Andrew an idea of how to solve that problem and it's still in use today. Again, a little pricey, (I think).
The Troyer Vertical Gourd
Andrew decided to also go with a version of the vertical gourd. Again, it's a blow molded gourd with an inspection port. It apparently comes with a number of different entrance options and no, I don't have any of them, but from what I've seen they are a good looking gourd with plenty of size for the martins to nest in. Again, it's not a cheap gourd.
The S&K Bo 11 Gourd
These were designed by S&K Manufacturing in O'Fallon Missouri and they are a good gourd. They have a black liner that fits inside the injected gourd, thus keeping it dark inside. (Some folks think this is a big deal, but not me). It also has an inspection port and also has a number of different entrance hole option. They are a fairly priced plastic gourd and many folks that have them say they like them. I have a few in my colony and yes, my martins readily use them.
The S&K Big Bo Gourd
My personal favorite, thus; I have a lot of them. This was one of the first gourds that was invented by S&K, blow molded with a snap-in front porch and, although there was an initial problem with the porches not having any UV protection in them and breaking prematurely, that issue has since been fixed and they are a good quality gourd. Being blow molded with nice thick walls, there's no liner in these, but they do have a screw on inspection port, a feature that I think is very important for keeping martins. They come with a number of different entrance options and changing to a new one is simply a matter of popping out the old one and popping in a new one. As with any other plastic gourd, they require a small handful of bedding to start the martins off and give them something to walk and rest on. And, for the money conscious, they are reasonably priced. And as I said, I have a lot of them. I just simply like them.
The S&K Double Gourd
S&K also has a double version of the gourd which I have a few of here at my colony and yes, the martins do use them. They are a deeper version of the Big Bo with the nesting compartment in the back of the gourd. They're pretty neat. I have about 5 of them here and every single one of them is usually used. And, just like all the others, they have a snap in front entrance and of course, the inspection port.
Now, let me also add, there are a lot more plastic gourds on the market, but after having seen most of them, I'm not very impressed. I've only mentioned a few of the better gourds here. I'm not going to mention any manufacturer's names of the cheaper ones, so I'm just going to say this. IF you plan to go with plastic gourds, LOOK AROUND. DO NOT just buy on price alone. There are a lot of cheap plastic gourds out there and they are just that, CHEAP. Small size, no inspection ports, round 2" holes only and cheaply made with paper thin walls. Most are manufactured to make the manufacturer money, not to better the hobby of keeping purple martins. If you're looking for plastics, consider this. No inspection ports, leave them on the shelf; just 2" round holes, leave them on the shelf; not at least 8" in diameter (measured inside), leave them on the shelf. Maybe after awhile, if they don't get sold, some of these manufacturer's will get the idea and upgrade their product.
If you've purchased one of these cheaper versions and want to know why you don't get martins in your plastic gourds, that's probably why.
I'm one that believes you get what you pay for (at least in most cases). If you want quality, then you're going to have to pay for it, but remember this. QUALITY LASTS, cheap doesn't. Do some reading, educate yourself and then make an informed decision before you buy.