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Helen Chesnut: Keep house plants cool, unfertilized

Dear Helen: I’ve been told not to fertilize my house plants in winter. When can I begin feeding the plants again? P.L. During the low light levels and short days of winter, the most appropriate treatment for house plants is benign neglect.
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This miniature cyclamen will bloom over many weeks in winter at a cool window. Helen Chesnut photo. Garden column Wednesday, Dec. 26.

Dear Helen: I’ve been told not to fertilize my house plants in winter. When can I begin feeding the plants again?

P.L.

During the low light levels and short days of winter, the most appropriate treatment for house plants is benign neglect. That means minimal watering as well as no fertilizing. This regime accommodates the plants’ semi-resting period and helps them get through the less-than-ideal winter conditions in our homes.

Exceptions are plants that are in active flowering mode, such as amaryllis, which, once active growth begins, should be watered enough to keep the soil moderately and evenly moist and fertilized every two weeks with a balanced formula at half strength. Continue this regime after flowering and keep the plant in the brightest possible winter light during this post-bloom period, when the bulb begins “recharging.”

Another factor to consider in the winter care of house plants is temperature. Excess warmth, and the dry air that usually accompanies it, are hard on most plants. Keeping the house on the cool side, or locating plants in areas not kept toasty warm, is helpful.

Dear Helen: Should all the fallen leaves be raked up or is it better to leave them in place?

G.F.

That depends on the type of leaves and where they have fallen. Very large leaves, such as fig leaves, are best gathered up and placed in shallow layers in a compost heap, or mixed into it.

Small leaves can be left in place in ornamental beds and emptied plots as a winter mulch. Just make sure that perennials are not smothered by thick leaf layers. Smaller evergreen and semi-evergreen perennials, such as primroses, are especially vulnerable to smothering. To avoid unsightly areas of dieback, it’s helpful to keep lawns raked free of leaves and debris.

I was fortunate this past autumn to “inherit” extra leaves from neighbours across the street. I was thrilled with the treasure of small, lacy maple leaves, which were perfect for creating a light, fluffy mulch over my emptied vegetable and annual flower plots.

A light mulch layer such as this helps to protect the soil from pounding rains and the leaves, dug under at winter’s end, enrich the soil and enhance the quality of its texture.

Dear Helen: I was given a most beautiful cyclamen in the week before Christmas. Now it seems to be dying down, still full of flowers. Can I save it?

B.P.

I’m guessing that your home is kept at fairly warm temperatures, or that the plant has been on display in a warm place. Cyclamens do not do well in warmth, which triggers dormancy in the plants.

For the longest possible bloom period, a cool spot with an overnight temperature down to 10 C is ideal, as is bright light. The plants I used to grow from seed flowered beautifully on the slightly chilly windowsill in my office.

Find a cool spot for your cyclamen. Keep the soil uniformly moist, but avoid pouring water onto the foliage or the centre of the plant. Pull away rather than cut the stems of faded flowers.

After the bloom period, it is natural for cyclamens to begin dying down. When this process begins, gradually reduce water and remove top growth as it withers.

When only the tuber remains, store the pot in a cool place, ideally at around 10 C, and water occasionally, only enough to keep the tuber from shrivelling as it enters a resting period.

As soon as top growth begins to emerge, repot the tuber, keeping its top at soil level. Situate the pot in a cool, lightly shaded area outdoors for the summer. Water regularly.

Monitor the plant for flower stems, which often will begin appearing in the fall. Bring the pot back indoors as blooms begin to open, or before frost.

Azaleas and chrysanthemums are more flowering plants that are commonly chosen as gift plants at Christmas. They need cool conditions as well, along with a humid atmosphere and a well-moistened soil.

Dear Helen: Should I be doing anything about foliage still clinging to shrubs and trees?

Some of my roses retain almost all their leaves.

R.S.

Clinging leaves are not a problem on most plants, but on roses, the old leaves can be sources of infection. They should be removed.

On climbers, you can minimize the time and labour involved by pruning out unwanted and overlong growth first. Do this in dry weather and in temperatures above freezing.