Mike,

One of my hobbies is breeding zinnias, and I use "hairnets" that I make from mesh fabric that I bought in the fabric department of Wal-Mart. The material is inexpensive and has an open mesh that allows easy air circulation and sun exposure, while keeping bees from getting at the flower. The nets don't harm the flowers or plants at all.

Interestingly, I have seen butterflies sipping nectar from the zinnias through the mesh, but they don't go after the zinnia pollen, so I am glad that the butterflies can feed through the mesh.

The nets are basically approximately square "sacks". I fold over a rectangular piece of the mesh and secure the top seam and side seem by weaving a piece of black yarn through the mesh. I alternate sides with the yarn about every ½" to ¾". The seam doesn't need to be really closely stitched. Obviously I leave the bottom open to allow the "hairnet" to fit down over the flower. I use black mesh and yarn because the black nets are less conspicuous in the garden.

I just started using these nets last year and they have revolutionized my zinnia breeding. I used to have to race the bees to get at the pollen on my selected breeder zinnias, but now I can relax and get the pollen over a period of half a day, and have an abundant supply of good pollen. The bees are amazingly aggressive at grabbing any available zinnia pollen. The nets also keep the bees from randomly pollinating my selected breeder flowers. Here is a picture of one of the nets on a zinnia. This zinnia was in rather poor shape because it is one that I grew from a cutting this fall and I just used it as a "model" to wear a net for this picture which I just now made. My breeder zinnias typically look much better than this one, as you can see for yourself by looking at their pictures in the It can be fun to breed your own zinnias message thread in the Annuals forum.

I make the nets in several sizes to accommodate different sized flowers. You shouldn't have any trouble making these nets to your own specifications from needles, yarn, and mesh fabric from a local fabric store.

MM

I have seen very bad results from flowers in plastic bags that got too hot. If you're working in cool conditions or shade it might usually be fine, though. Also, if you're bagging something to perform a controlled selfing, high humidity can result in clumping of the pollen and a failure to shed properly.

When I worked with breeding grapes I always used paper bags, which generally worked well (the difficulty I found was finding ones sufficiently small to avoid catching too much wind but sufficiently large to house a fairly large cluster without damage.) When I went to working with blackberries, I would sometimes use very fine mesh bags (much finer than that shown above...really so fine it was hard to make out the individual openings). These worked very well, but unfortunately I couldn't tell you where to buy them--there was a huge box some one had ordered ages ago that had lasted for years. However, in most cases with blackberries or with strawberries (which I work with now) the emasculation process removes the nectaries, so insects wouldn't be interested in it at all. A bag can still prevent windblown pollen, but I think the risks of that are pretty minimal, and I now do my crossing in a greenhouse anyway.