Extra Fields in Products Table?

I sell plants. They have particular characteristics that form common sets for gardeners to search. Sun, Partial Shade, Full Shade, USDA Hardiness zones 1 through 11. Evergreen or Deciduous. Blue, Red, Pink, Green...and on and on. So, let's say a customer wants to search for a plant suited to zone 7, partial shade with pink flowers. With the current search setup, this doesn't pull accurate choices because it looks all through the description. The zone choice is usually way off due to many numbers showing up in the descriptions.
There are sites (some direct competition) that have "plant picker" search forms that will drill down and respond only with plants suiting the characteristics. These are not "attributes" or "options" because they can't be chosen for a given product. They will always be the same, so I call them characteristics.
** Now for my question:** What would happen if I added 40 more fields to the product table? They would be simply yes or no for any given characteristic. The goal is to adapt the search form to look at these and accept only the products meeting all of the criteria. This would be done with check boxes.
I asked in the past about using the attributes for this and was told that it would be a big drag on the server. Does this use less? The fields wouldn't show anywhere on the site and the only time they'd be called would be in the "plant picker". The shop will never have more than 1000 products; at least not for the forseeable future.

It could be done either. As read-only attributes you would have a built in way to maintain the data, though with that number it would be a bit clunky. The custom search facility that you would need to write would be quite complex too.

As extra columns on the product table (or an extension table) you'd still have to write a custom search script, but it wouldn't be as complicated. That would be offset however, byt the need to extend the admin product pages to maintain the additional data (unless you have another way of loading it).

Thanks for the prompt reply! Would the read-only attributes drag the system performance down? I'm hosted on a mid-level VPS; nothing too fancy.
i'd rather not build from scratch, though. How would the search function work out for attributes?