Ruth Kassinger's Blog, page 4

Buggy Houseplants: Should You Use Horticultural Oil, Insecticidal Soap, or Pyrethrins?

I  brought my citrus trees inside from the backyard last month. Although I blasted them with water from a garden hose beforehand, I know I’ll soon see spider mites, mealy bugs, and aphids on their leaves.  Outside, these harmful bugs are kept in check by beneficial insects. I could buy beneficials online, but that’s an […]

‘Tis the season of pomegranates, a very twisty fruit.

Here, in the northern hemisphere, we’re in pomegranate season. Miriam Crook asked me about the arrangement of the seeds inside. Other fruits seem to have an orderly internal structure, and their seeds align. Not so in the pomegranate. The arrangement of the thick white tissue and seeds seems random. What’s going on? The short answer […]

600 Blooms on a Single Chrysanthemum Plant: The Art of Trickery

I just saw the Thousand-Flower Chrysanthemum at the US Botanic Garden. This umbrella-shaped beauty is a single plant. All the flowering branches grow off a single slender stem. Creating this example of “ozukuri” involves exploiting the physiology of chrysanthemums. To create the plant, the gardeners first had to trick it into growing without producing flower […]

Dandelions: an old weed becomes a new rubber crop

Dandelions are the new rubber trees. If you’ve ever dug up––or tried to dig up––dandelions, you may have noticed a bit of white latex sap that drips out of broken roots and stems. German molecular biologists and engineers have bred dandelions particularly rich in that sap. In concert with Continental, a German auto supply manufacturer, […]

Plants do arithmetic and tell time to make food last through the night

During the day, a plant’s leaves convert the sun’s energy, carbon dioxide, and water into simple sugars and more complex starches. The plant burns some of those foods immediately to carry out its normal functions. It stores starches in excess of its immediate needs, and uses them at night to grow or make repairs when […]

Giant Pumpkins Go To the Races

If you’d started a giant pumpkin in your backyard last spring and tended to it assiduously (see my previous post), you might have a fruit large enough to  take to the Damariscotta Pumpkinfest. Damariscotta, a town on the coast of Maine an hour north of Portland, is the place to win fame, if not fortune, […]

Citrus, Thorns, and Evolution

Why do some citrus species have wicked thorns, Trish Carr asked, and others don’t? All four ancient citrus types––the citron, the pomelo, the papeda, and the mandarin––had thorns. All the citrus species we know either evolved from one of the originals or are the result of hybridizations, purposeful or random, among them. Thornless varieties are […]

One-Ton Pumpkins: How They Grow So Blooming Big

‘Tis the season of Giant Pumpkin competitions. This year’s champion is 2032 pounds. Picture an orange SmartCar lying on its side, and you’ve about got it. So, how do you grow such a behemoth? A huge factor (so to speak) is genetics: you have to start with a seed from a Cucurbita Maxima. Germinate your […]

When Leaves Freeze, Why Do They Die?

We in the DC area haven’t had our first frost (besides between Democrats and Republicans), but it’s coming. When it does, many leaves that are still green will die. But why, exactly? When water inside individual leaf cells freezes, it forms ice crystals that rupture the cell walls. When later the ice melts, the water […]

Blueberries, Grapes, New Health Evidence

Scientists have long noted that two compounds in blueberries and grapes seem to reduce inflammation and improve cardiovascular health. A new study shows that the two compounds, resveratrol and pterostilbene, interact with Vitamin D to increase expression of the human CAMP gene severalfold. The CAMP gene plays an important role in activating the immune system. […]