In the Garden: December

In November, I visit my sons in California, where the weather is still mild and there are more hours of daylight than there are along the northern border. Today – November 17 – the So Cal sun rose at 6:33 a.m. and will set at 4:48 p.m., providing 10 hours and 15 minutes of “daytime” despite heavy clouds and a few hours of light rain. I gleefully compared that to today’s stats for Point Roberts, with 9 hours and 3 minutes of “daytime” between 7:35 a.m. and 4:28 p.m.

While Bakersfield winters are mild with a mere six inches of annual rain, today definitely looks and feels like winter. That means I’m spending the day indoors, tending to my oldest son’s houseplants that reside on the kitchen counter next to a shaded window.

Chances are that some of you have houseplants that resemble his: outgrowing their pots and sporting an abundance of pale green leaves with brown spots and crispy dried-out tips. I know for a fact that the last time these plants were groomed was when I visited in March and gave them a bath to remove the dust and the light coat of cooking oil that often settles on kitchen plants, followed by a much-needed indoor plant haircut.

So that’s what I did this morning. I began by washing my hands and wiping the leaves with damp towel. Then I sterilized the sharp kitchen scissors with rubbing alcohol and removed the deeply yellowed and/or shriveled leaves that had no chance of recovery, cutting their stems at the soil level.

I also wiped down the outside of the plastic pot with a rubbing alcohol saturated paper towel and checked the soil for gnats or other insects. I then placed the pot in a bowl of cool water and let it sit for an hour to saturate the soil.

I noticed the crown of the plant was now nearly two inches above the soil line and there were many roots exposed to the air. I removed the plant from the pot to check the condition of the buried roots: they were tightly packed and had grown in circles around the sides and bottom of the pot.  I carefully trimmed back nearly an inch of roots on the bottom and a bit less on the sides, then loosened the remaining roots with my fingers, gently removing a bit of the old soil.

Having freed up some space in the pot, I moved forward. I wiped the inside of the pot with rubbing alcohol and rinsed thoroughly. Then I added two inches of fresh potting soil, set the plant on top of the new soil, and carefully added about half an inch of soil along the sides, tapping the pot gently against the counter to help the soil settle. I watered again, tapped again, and added a bit more soil and water.

Grooming your indoor plants is an important task that should be done at least twice a year. Potting soil does not contain actual soil – AKA dirt – but it does contain enough bedding material and plant food in the form of synthetic or organic fertilizers to keep your plant well-nested and well-fed for three to six months.

If your indoor plants look sad, droopy, or are losing a lot of leaves, it’s generally a sign that they need more water or less water, more or less light, a warmer or cooler environment, or perhaps a gentle cleaning and trim. And be sure to check for soil pests and signs or disease. If your plants are well cared for, the cause of plant issues is more likely to be too much fertilizer rather than too little.

Several local gardeners have told me about the success they’ve had feeding banana peels to their houseplants. Banana peels are an excellent source of potassium, a nutrient all plants require: it’s the “K” in NPK initials on the soil and fertilizer packages. Some people swear by watering with banana peel tea made with boiling water. Others chop up banana peels and lay them on top of the soil.

Is there any scientific evidence that the use of banana peels works? None that I’m aware of, and it’s my job as a Master Gardener to stay abreast of current developments and offer science-based information and advice. There’s no way to know if your plants need a specific nutrient without a soil test.

If you’re concerned about the health of your houseplants, and you’ve tried the changes shown above, changing or refreshing your potting soil is usually a safe option that won’t make the problem worse. The bottom line is that not all plants thrive and survive. Growing plants makes the world a better place, so keep at it and enjoy the process and the joy it brings.