George's Current Ramblings and Readlings

What to Do About Wacky Warm Weather

March 26th, 2024

   Another warm winter has faked the landscape into acting like we’re farther ahead on the calendar than we really are.

Ahead-of-schedule buds and blooms are more susceptible to this kind of cold damage than plants that maintain their winter dormancy longer.

   That’s not a problem if the weather course stays full steam ahead. So long as temperatures don’t nosedive in the coming weeks, the upshot is that we’ll simply have an early spring. Plants will bloom earlier, and growth will advance sooner than usual into a normal growing-season pace. No problem.

   The trouble is if the weather decides to back-track into traditional norms or less… or worse yet, yo-yo’s between abnormally warm and abnormally cold. Plants like sudden change even less than people.

   The way it used to work most years, plants stayed dormant long enough to protect themselves against early to mid-spring freezes. But when flowers and buds open early due to the kind of sustained warmer-than-usual temperatures we’ve been having in recent winters, they lose some of that protection.

   Open flowers or too-far-along leaf buds are much more susceptible to cold injury. Temperatures that they would have sloughed off while dormant can cause damage to this advanced growth.

   Sometimes a few degrees can make the difference.

   Smaller bushes can be draped overnight with a floating row cover or sheet to give a few degrees of protection in a frosty forecast, but there’s no good practical solution to help a 20-foot tree. (Orchardists run misters all night.)

   If the worst happens, cold-killed flowers will result in few or no fruits (on species that produce fruits and berries), while prematurely advanced leaf buds can result in browning around the leaf tips and margins.

   We’ve seen that happen several times in the last decade as our winters have warmed but early spring didn’t get the memo that the buds were beyond dormancy.

   Plants normally grow through these setbacks, but it’s a blow to that year’s performance.

   This wacky up-and-down stuff (not to mention even a single very cold snap in the middle of an otherwise warm winter) is also enough to cause browning on evergreens – especially broad-leaf ones like azaleas and boxwoods.

   If you’re seeing some brown, brownish, or even bare evergreens, don’t despair. They may not be mortally injured.

2024 Philadelphia Flower Show Reporter’s Notebook

March 11th, 2024

   The just-ended 2024 Philadelphia Flower Show was another typically wow event with its 75,000-flower main-entrance garden, billboard-sized floral map of the U.S., and floral “clouds” hanging from the ceiling.

The flower show’s Main Entrance garden had color every which way you looked.

   But among the blooming glitz was a lot of fascinating plant and gardening information. Here’s a sampling that filled this reporter’s notebook.

See George’s PennLive.com post with pictures on 14 of the coolest sights at the 2024 Philadelphia Flower Show

The show’s big buzz

   The U.S. Geological Survey Team (of all entities) had an eye-opening display on the importance of native bees, which are getting a lot of love lately for their pollinator services.

   Did you know Pennsylvania, Maryland, New Jersey, and Delaware, have 450 species of native bees, and that many of them look more like mini-houseflies than the lumbering bumblebees that most people envision when they think bee?

   USGS says two of the best things gardeners can do to help dwindling populations of native bees are: 1.) replace lawn space with flowering plants (especially native species), and 2.) drill 1/8-inch to 5/8-inch holes in dead wood around the yard to encourage nesting.

   For everything you’d want to know (and see) about native bees, check out USGS’s Bee Lab website.

“Speed dating” and the vanilla orchid

   Vanilla is the world’s second most expensive spice for good reason. (Saffron is number one.)

These are pods of the vanilla orchid drying.

   Not only is the vanilla orchid vine finicky about weather, it has only a 12-hour window of pollination, and it depends on one specific bee to do the deed.

   “Talk about speed dating for flowers!” Waldor Orchids pointed out in the signage on its vanilla orchid display.

   That super-specific requirement is why vanilla growers have to hand-pollinate flowers – one-by-one at the precise time – to induce the plants to produce the long, skinny bean-like pods that give us our beloved flavoring.

   Harvest time is also short and tricky, plus it takes two months of curing to ready the pods for processing.

   Vanilla is the only orchid that gives us edible fruits, says Waldor Orchids, which showed us 16 tripods of vanilla orchid vines growing in a tropical garden at the show.

The World’s First Purple Tomato

February 27th, 2024

   We’ve had purple- and dark-blue-skinned tomatoes for years now, but this month marks the arrival of the world’s first tomato that’s a true, dark purple throughout.

The Purple Tomato is purple throughout, not just at the skin level.
Credit: Norfolk Healthy Produce

   For now at least, it’s called simply The Purple Tomato, and it’s a bioengineered cherry-type tomato that gets its purple coloring from the genes of a purple snapdragon.

   That’s what makes this variety particularly ground-breaking – it’s the first time a genetically modified food crop is being marketed directly to consumers. Up to now, so-called GMO crops have been grown by commercial producers.

   Norfolk Healthy Produce, the California start-up that’s the sole source of The Purple Tomato, began selling seeds to home gardeners earlier this month. They’re priced at $20 for a pack of 10 and available only through Norfolk’s website.

   What remains to be seen is how well the idea goes over since a large chunk of the American product is leery about bioengineered/GMO foods.

   Although the U.S. Food and Drug Administration has found no ill effects from eating bioengineered foods, slightly more than half of Americans have GMO health concerns, according to a 2020 Pew Research survey.

   British biochemist Cathie Martin started work on The Purple Tomato 20 years ago by identifying a gene that gave a snapdragon its purple flowers. She then used a bacteria to insert the genetics into tomato plants.

   The effort got a green light last year from the U.S. Department of Agriculture.

What the New USDA Hardiness Zone Map Means for Gardeners

February 13th, 2024

   If you pay attention to which plants tend to croak in our winters – and as a gardener, you should – you’ve probably noticed less cold-weather mayhem over the past 20 years or so.

USDA came out with this newly revised Plant Hardiness Zone Map late last fall.

   Although our temperatures can nosedive to zero or below, that’s been happening less and less. And as a result, our odds have been growing that we can get away with plants that not too long ago were considered “iffy” at best in our climate.

   The U.S. Department of Agriculture has now verified what gardeners have been suspecting for years – our winters generally aren’t as plant-killing cold as they used to be.

   USDA late last fall released an updated version of its Plant Hardiness Zone Map – the official, national guide that gardeners and farmers use to estimate how low temperatures are likely to plunge in an average winter.

   These zones are listed routinely on plant tags and are a key determiner of what plants gardeners plant in a given area and which ones garden centers carry in the first place.

   The new map is based on 30 recent years of nationwide observations – from 1991 to 2020 – that show our winter lows are about two degrees warmer, on average, than the decades before.

   USDA last updated the map in 2012, using temperature readings from 1976 through 2005.

   The readings went up enough over the more recent period to cause USDA to shift about half of the country – Pennsylvania included – into higher half-zones.

The Best New Trees and Shrubs of 2024

January 30th, 2024

   A hydrangea with dark leaves, a mock orange that reblooms, and an inkberry holly that solves the “bare-legs” problem are among the most interesting new trees and shrubs hitting the market for the 2024 growing season.

Eclipse is a mophead hydrangea that combines dark foliage with cranberry-colored flowers.
Credit: Bailey Nurseries

   Growers, local garden centers, and other plant experts mentioned the following 12 choices for my annual January four-part, best-new-plants series.

   Today’s new trees and shrubs make up the final installment of this year’s series.

   Part one on best new edibles of 2024 appeared on Jan. 9, part two on best new annual flowers of 2024 appeared on Jan. 16, and part three on best new perennial flowers of 2024 posted last Tuesday, Jan. 23.

   Some of the following new tree and shrub varieties are available online and in some plant catalogs. Most also will be available in local garden centers beginning in April.

   The details:

Hydrangea Eclipse

   This new bigleaf hydrangea in Bailey Nurseries’ First Editions line is being touted as the “first true dark-leaf mophead hydrangea.”

   Ryan McEnaney, “Field Guide to Outside Style” author and Bailey communications manager, calls Eclipse an “impressive bloomer and solid garden performer.” But he says what really sets the variety apart is it “has such dramatic and different foliage than any other hydrangea out there. It gives you the opportunity to do something different with one of the most sought-after plants in the world.”

   McEnaney adds that the dark-purple leaves hold their color even in warm weather and pair nicely with the ball-shaped, dark-purple to cranberry-colored blooms.

   Eclipse turned enough heads at last summer’s AmericanHort Cultivate show that it won a Retailers’ Choice award as a new plant with the potential to become a garden-center best-seller.

   It also won the 2024 National Garden Bureau Professional Choice Green Thumb Award as the year’s top new shrub.

   Plants grow three to five feet tall and wide, ideally in morning sun and dappled afternoon shade.

Could Worry Free Ruby Snow be the best panicle-type hydrangea yet?
Courtesy of Overdevest Nurseries

Hydrangea WorryFree Ruby Snow

   Lots of superb new panicle hydrangeas have come along in the last 10 years to make this species one of our showiest and easiest-to-grow summer-blooming shrubs. So it takes a lot for yet one more newcomer to make a noticeable dent in an already-impressive field.

   Lower Paxton Twp. horticulturist David Wilson, marketing director for Overdevest Nurseries, believes Ruby Snow manages to do that with its huge, sturdy, long-lasting, color-changing flowers that end up in a deep ruby-red color even past frost.

   Wilson says the over-sized, cone-shaped flowers start out “gleaming white” in early summer, then take on a soft-pink color, and then intensify into a bicolor bright pink with white tips before morphing into ruby-red by late summer into fall.

   “It flowers all over the plant, and it has a tremendously long seasonal display,” Wilson says. “We’ve been testing it for five years and planted it out to compare it with all the major hydrangea panicle introductions. I have come to the conclusion that this is the best panicle selection I have ever seen.”

   Besides the flower performance, Wilson adds that the sturdy stems hold the big flowers upright. “It doesn’t flop like many old-fashioned varieties that hang their heads,” he says.

   Ruby Snow grows a compact four feet tall and five feet wide and does well in full sun to part shade.