In my never ending quest to let no plant go un-nurtured I'm driven to divide, compelled to take cuttings, and otherwise obsessed to increase my plant stock. But once multiplied what to do with new plants? Thriving houseplants may grow so much in a year that I must transform one into two or three. More extra plants! Spring seedlings are another source of worry. What can I do when too many little tomatoes live?
Like puppies in a cardboard box, "free to good home" plants offered at work can be nearly irresistable.
First of all, try to take a step back and look at your plant offerings through the eyes of the non-plantaholics of the world. Most of the people you work with don't know a Heliopsis from a hole in the ground. Offer plants that are either commonly known in your area, or have instant appeal. Tomato seedlings fall in the common plants category. They're easy to give away because so many people have grown them in the garden. Common indoor plants are well appreciated too. The "usual suspects" of indoor tropicals (spider plants, Spathiphyllum, Aglaonema, devil's ivy) are SO easy to care for and propagate they may be a snooze for you. Those same plants are snatched up by coworkers in need of a new green companion in the cubicle. They play it safe, and you get a reputation for giving away amazing plants.
You can deviate from the "common" rule when you offer plant material with instant and obvious appeal. Chocolate mint is a poster child for an appealing plant. One touch releases the most delicious chocolatey, minty girl-scout-cookie scent. The glossy dark green leaves, and that scent, guarantee those plants will be gone by the end of day. Anything that is in bloom, smells terrific or is just gorgeous will be taken. The opposite end of the spectrum in appeal would be a naked Brug in midwinter. It's not likely that you'll entice anyone with a seemingly dead dormant plant, without a lot of promotional material to go along with it. Save the effort and put up a note announcing a free BRUGMANSIA or whatever, and contact information. If the building houses a fellow lover of all things exotic in the plant kingdom, he or she will home in on that note like a bee to honey. You may find yourself a new plant buddy, too.
Nice presentation is also a key to your plants being loved and taken home. Plants meant to stay in pots are best presented in a clean inexpensive pot, sized appropriately for the plant. Plants meant for the garden can look a little more temporary (think McDonalds cup) but if given in cleaned leftover nursery pots or sixpacks, they will look nearly professional. In either case, use a container reasonably sized for the plant, so it will fend for itself for a week while waiting for adoption. Clean the pot and set the whole works in a bag or box. Make sure it isn't drippy wet or sheltering any tiny critters. A sloppy plant might cause some coworkers to gripe, but a buggy one will get you real grief from the boss.
Finally, with all but the most common indoor plants, a label is a must. (Got golden pothos? Everyone knows what to do with it: put it on top of the file cabinet, dump your coffee dregs in the pot once in a while, and go on about your business while the plant generally looks "fine" for months.) Seriously though, as a dedicated gardener, I'm sure you won't pass along any tomato seedlings without at least the proper cultivar name affixed. Anything that has instant eye appeal but is lesser known, should carry not only the name (widely accepted common name if you must, Latin to show off your smarts) but also suggested growing conditions.
Using the above principles, I've had all plant offerings magically disappear from their temporary home in an office break room. I wish you similar luck in spreading your love of plants.