Houseplant care and other September gardening tips

Acclimatizing houseplants, dividing daylilies, and controlling slugs are some of the garden activities for this month.

Gradually condition or “acclimatize” indoor plants that have spent the summer outdoors to lower light conditions. Move them to a shady spot outdoors for a week, then move them into the sunniest spot indoors for a couple of weeks before moving them to their permanent locations. Dunk them in soapy water to clean the foliage (a sink or bathtub is handy for this), and spray with insecticidal soap if insects are a problem.  Do they need repotting?  Now is a good time before bringing them in.  Make sure if they’re still outside to not expose them to early frosts or near-freezing temperatures.

If daylilies are getting too large, perhaps not blooming well, it may be time to divide them.  Daylily clumps are so dense that you’ll need to slice through them with a shovel or spade. Or you can just divide off half, or a chunk, leaving the rest.  Separate large clumps into smaller divisions, leaving at least three groups of leaves or “fans” per clump. Trim leaves to about six inches long and replant. Keep them well-watered if it doesn’t rain sufficiently, and they will settle in by winter and bloom again next summer.

Legumes, such as beans and peas, have the ability to take nitrogen from the air and use it for their own benefit. Rather than pulling up the spent plants and adding them to the compost pile, why not keep that nitrogen where it’s needed by chopping up the vines and tilling or digging them into the soil.

Fritillaries are less common spring-flowering bulbs that you plant in the fall as you would the more common daffodils and tulips.  Their flowers come in a range of colors, and are generally bell-shaped, either in clusters or single.  Plants range from six inches to the three-foot tall crown imperials.  The one-foot tall checkered lily, so named from the generally purple checkered bell-shaped flowers, is one of the few bulbs that can withstand wet soils.

If slugs have been a big problem, consider raking leaves off your garden beds and leaving them bare for the winter so the cold will kill any exposed adults and eggs.  You can trap slugs in rolls of moist newspaper left in the garden, then discard.  Or place small boards where they hide under by day and you can find them.  Other controls include bands of egg shells or similar crushed and sharp materials, copper products, diatomaceous earth or coffee grounds sprinkled around plants, or traps with beer.

When the first frost blackens the foliage of dahlias (or if a hard freeze is predicted), cut off the stems about 6 inches above the tubers. Carefully dig the clumps with a spade or fork, and let them dry out of direct sun and wind for a day (not too long or they’ll begin to shrivel). Store the tuber clumps whole (you’ll get larger plants), or make more plants by carefully separating the tubers from the stem, making sure to include any “eyes” (small, raised nubs near where the tubers attach to the main stem) with each tuber. These are the future sprouts. Store tubers in cardboard boxes or mesh bags filled with peat moss, vermiculite, or sawdust. Keep them in a dark, 40- to 50-degree (F) location.

Other activities for this month include planting spring-flowering bulbs, visiting an apple farm, keeping up with mowing, and storing (freezing, canning) produce for later use.

HOUSEPLANT CARE AND OTHER SEPTEMBER GARDENING TIPS

Leonard Perry, UVM Horticulturist
and Charlie Nardozzi, Garden Consultant

Charlie Nardozzi is a nationally known horticulturist, author, gardening consultant, and garden coach (CharlieNardozzi.com).  Distribution of this release is made possible by University of Vermont and Green Works—the Vermont Nursery and Landscape Association.