Many plants are easy to share -- maybe too easy.
A friend may have mint, lily-of-the-valley or violets to spare because they are aggressive spreaders. Such plants can cause headaches and backaches unless you place them where they can't crowd out everything else. Plants that readily reseed, such as cleome, also may sometimes be a nuisance.Some plants may bear pests or have weeds or weed seeds in their soil. So examine gifts carefully before planting them.
So accept plants gratefully, but get as much information as you can from the giver. Identify the plant for certain and research it carefully before you decide whether to use it. You can take the plant or photos of the plant to the Plant Information Service at the Chicago Botanic Garden, 1000 Lake Cook Rd., Glencoe, 847-835-5440, or the Plant Clinic at The Morton Arboretum, Illinois Highway 53 north of Interstate Highway 88, Lisle, 630-968-0074. Once you know the name of the plant, go to an Internet search engine and put the name and the words "invasive" and "USDA" in the search box to check if the plant has been flagged as invasive.
Now, if you want to share your plants, here are some techniques:
Cuttings: This is an especially easyway of multiplying annuals, perennials and houseplants -- anything with a fleshy stem, according to John Rafetto, horticulturist at the Garfield Park Conservatory in Chicago, where they start thousands of cuttings a year.
Cut off the end of a stem from a plant that is actively growing. It should be 5 or 6 inches long with two or three leaves. Trim the end back to just below a leaf and pluck off the leaf. Immediately stick the cut end into a small pot of wet sand or perlite (soil would hold too much water and invite rot). Keep it evenly moist until it grows roots (you can tell if, when you tug gently, it resists pulling out of the sand). Many plants will root in two to four weeks. Transplant the rooted cutting in a pot of appropriate soil mix or to a garden spot with the right conditions.
Some plants, such as coleus and philodendron, will grow roots if you place the cut stem in a glass of water.
To give away cuttings, cut longish pieces and place them in a plastic bag with a damp paper towel. The giftee can trim the stem ends and root them.
Start at least three cuttings of each kind, because many cuttings don't take, Rafetto says.
Dividing perennials: You can dig up the root ball of a perennial or biennial, replant part of it, and give the rest away. Most perennials need to be divided every few years anyway. To avoid missing a season of flowers, divide spring bloomers in fall and summer bloomers in spring.
Dig all around the plant, but not so close that you slice the roots, says Jeanne Felknor of the East Village Block & Garden Club, which maintains dozens of parkway gardens completely filled with salvaged and passalong plants.
Gently shake the soil off the root ball and pull it apart if you can, using as little force as possible, Felknor says. For dense, fleshy roots such as hostas and daylilies, you may need to slice them with a sharp knife. Depending on the size of the clump, you may get two, three or more plants.
Have a watering can and plastic bags handy so you can keep the roots of the divisions moist.
Volunteers: Many plants, such as columbine and winter aconite, reseed readily or spread by creeping stems, so that small plants appear nearby or elsewhere in the garden. Dig the little plants up, keep their root balls moist in plastic bags or pot them up and give them away.
Saving seed: Among Felknor's favorites for seed-saving are hollyhocks, cleome, marigolds and nicotiana. Wait until the seed ripens in the fall. Gather the seed (or the whole pod or whole flower head) in a paper bag or envelope. Be sure to keep the different kinds separate.
Label seeds carefully and keep them cool and dry (not in plastic bags) until they can be sown. This works best with plants that are not hybrids; hybrid varieties may be sterile or not keep the same characteristics in the next generation.
Of course flowers can't turn to seeds if you cut them off, so don't deadhead all the blooms you want to share.