Questions Pop Up As Spring Approaches

I can always tell when spring is right around the corner. Garden questions start popping up like weeds. So today, let’s nip a couple of questions in the bud - how to bring overwintering geraniums out of dormancy and how to deal with nasty fungus gnats.

First, geraniums: The process of awakening slumbering geraniums can start now. We’ll need a pail of warm water, a collection of 4- or 6-inch pots, potting soil, sharp shears and a bright, sunny window or a bank of growlights.

Begin by submerging the roots for a few hours in a bucket of warm water. Not only will this help rejuvenate the plant, but it will make working with the roots much easier.

One by one, lift the plants from the bucket, allowing the roots to dangle. If they’re twisted and knotted, untangle them, forcing them to hang straight. With scissors or sharp shears, cut the roots straight across leaving them only about 4 inches long.

Once that’s completed, move on to the plant itself. Prune all the stems to within 4 to 6 inches of the would-be soil line. All squishy or blackened diseased stems must be removed even if it means cutting them down to the base of the plant. And of course, whenever we cut into diseased tissue, we should always disinfect the shears between pruning cuts with a bleach solution - one part bleach to nine parts water.

The third step is to pot the plant. The size of the root system will determine the size of the pot - 6-inch pots for the big guys and 4-inch pots for the smaller fellows. After planting, water to settle the soil around the roots.

Now that we have dozens of geraniums potted up, what do we do with them? Anyone can clean and repot overwintering geraniums, but not everyone has the right light to maintain them before they go outside. Geraniums need very bright light in a cool spot. If you don’t have a south- or east-facing brightly lit window, you may need to use a bank of growlights. The lights should be left on for 12 to 14 hours a day and suspended about 4 to 6 inches above the plants.

Keep the plants moist and fertilize with a balanced fertilizer every two weeks. By late April, begin hardening the plants to the outside by taking them out for a few hours at a time, eventually leaving outside for good.

This rejuvenation process also includes geraniums that have been allowed to grow on the windowsills all winter. If they appear leggy (long stems and few leaves), cut them back to within 4 to 6 inches of the soil line, followed by water, fertilizer and light. If the pruned stems seem healthy, start new plants by rooting them in potting soil or a glass of water. These healthy little cuttings should reward you with lovely plants come spring.

Second, as for the little black flies buzzing about the house, they are probably fungus gnats. The adults are no more than a nuisance, they don’t harm anything. It’s their larvae we should be concerned about. The larvae feast on organic matter and plant roots. Most all potting soil for houseplants is primarily made up of organic matter.

You can control them, but only with great diligence. First, try to locate the source of the infestation. Once the culprit plant is identified, go to work. Repot the plant. Wash all the soil from the roots and disinfect the pot with bleach. Or, set the plant in the bathtub and flush the soil with warm water, after which you let the plant dry completely before watering it again. Gnats require damp soil to survive. Of course, not all plants can tolerate dry spells. This is another case for knowing the cultural requirements of your plants.

Or, you can try using a houseplant systemic soil drench. Remember, it must be a systemic that is formulated for houseplants. Systemics that are used on plants outside are not registered for indoor use.

Or, try this method: Cut up a few pieces of oranges or apples and place them in a baggy. Set the baggy on the soil under the plant with the end open. You might be surprised at how many of these little culprits you attract. You might even trap a few larvae by burying a piece of the fruit in the soil. Check the fruit often. When it’s full of worms throw it out.

Oh, the interesting world of hands-on gardening.

Of special note

On Feb. 12 - that’s next Friday night - the Friends of Manito are offering a beautiful program on the gardens of France and England. The program will be presented by Diane Notske at 7 p.m. in the Manito Park Meeting Room (at the east end of the conservatory). The program is free and will be absolutely spectacular.