Houseplants: Share the wealth

I have three houseplants I’d like to share with a friend: a heartleaf philodendron, ZZ plant, and an African violet. What’s the easiest way to divide them?

Many houseplants can be shared. Some root from leaf or stem cuttings, others can be removed from the pot and divided at the rootball. All three of the plants named here are easily propagated.

Heartleaf philodendron: These are easy to root from stem cuttings. You can try to simply cut the tip of a stem with several leaves from the parent plant just below a node (where a leaf attaches to the stem). Remove the bottom leaves, and place the stem in a jar of water. Change the water frequently, and with luck, the stem will begin to grow roots at the node. When there are enough roots to support the plant’s growth, transfer it to a pot filled with sterile potting mix.

A better method, though, is to dip the freshly cut stem in rooting powder (usually sold in garden centers) and stick the stem into seed-starting mix. Water the mix gently, or spray with a mister, and cover the pot and cutting with plastic. Mist it daily. New growth should appear in a few weeks, and the new philodendron can be transplanted into regular potting mix.

ZZ plant: Zamioculcas zamiifolia – ZZ for short – grows from rhizomes (fleshy, sometimes bulbous underground stems), so it’s a simple task to share parts of an overgrown plant. Simply lift the plant out of the pot and separate the rhizomes by pulling them apart gently Replant the rhizomes into clean pots with new potting mix, water, and maintain as usual.

You can also propagate ZZ from plant cuttings. Plant the cuttings in potting mix that drains well, water lightly, and place the cuttings in a warm, brightly lit area. This is a slow-growing plant, so it may take weeks or months before the new plant shows signs of rooting. Whatever you do, don’t overwater. ZZ is usually happier on the dry side.

(For more information about Zamioculcas zamiifolia, check out my article How to Care for a ZZ Plant at HGTV.com.)

African violet: These sweet little plants are easily shared by rooting petiole (leaf stem) cuttings. Cut a healthy leaf with its stem from the parent plant, trim the stem to about and inch or inch-and-a-half long, and stick the end of the stem into damp seed-starting mix. You may want to cover the pot with plastic to keep the cutting humid and warm. In any case, check daily to make sure the soil remains lightly moist. In a few weeks, you will see tiny plantlets emerge from the soil. At that time, you can transplant it to regular potting mix and cut away and discard the parent leaf.

This is a good technique to use when you accidentally knock a leaf off your established African violet. More plants for your friends, and for your own indoor garden!

Divide irises after they bloom

Our bearded irises are coming up and they’re pretty crowded this year, and need to be dug up and divided. If we divide them now, before they bloom, will we still have flowers this year?

If your iris bed is crowded but still producing blooms, it is best to wait until later to dig up the iris bed and divide the rhizomes. The experts at the American Iris Society and other sources say iris beds should be divided every three to five years, and suggest mid- to late-summer as the best time for this task.

When the time comes this summer, here is the method suggested by author Judy Lowe in Month-by-Month Gardening in Tennessee & Kentucky:

Cut the leaves in a fan shape about 6 inches tall, then lift the clump with a spading fork, wash off the dirt, and inspect the rhizome for soft spots, damage or disease.

Cut the rhizome into smaller pieces with a sharp knife, making sure each piece includes an eye or a bud. Cut away any older growth. Lowe notes that iris rhizomes are susceptible to fungal problems, and suggests dipping the rhizome briefly into a solution of one part liquid bleach to nine parts water.

Replant the sections: Dig a hole and make a mound of soil in the center, then place the rhizome on top so that its roots spread over the mound. Cover the roots, but maintain the rhizome at soil level or just below it. Bearded iris rhizomes that are planted too deep may rot, she says. Water the bed well.

Dividing in summer allows the rhizomes to become established before the end of the growing season, and more likely to bloom well next spring.

Color Garden book giveaway

Thanks to readers who left comments this week for a chance to win The Nonstop Color Garden by Nellie Neal. Constance is the winner of the random drawing.

Nellie, her book, and information from Doris Weakley of the Perennial Plant Society of Middle Tennessee were featured in a story in last Saturday’s Tennessean. You can read it here.

And watch for another book giveaway soon.