George's Current Ramblings and Readlings

Award-Winning Plants of 2022

March 22nd, 2022

   Which plants will work best in your yard?

Coralbells ‘Caramel’

   One strategy is considering plants that have won awards from various plant-trial and plant-selection programs.

   Each year, organizations of growers, horticulturists, researchers, and other plant experts bestow awards on top plant performers – some new, some old but just under-used.

   Here’s a look at plants that have won honors for 2022:

Pennsylvania Gold Medal

   A panel of experts assembled by the Pennsylvania Horticultural Society (best known for running the Philadelphia Flower Show) each year picks a half-dozen trees, shrubs, and perennials worthy of greater use in Pennsylvania landscapes.

   For 2022, two perennials, two shrubs, and two trees made the Gold Medal grade.

Coralbells ‘Caramel’

   ‘Caramel’ is a buttery-gold-leafed version of our native alum root (Heuchera villosa) that grows about 14 inches tall and 30 inches wide, ideally in a site that’s out of afternoon sun. It’s a perennial grown mainly for its foliage, although it does produce some wiry white flowers in early summer.

Clustered mountain mint

Clustered mountain mint (Pycnanthemum muticum)

   Gardeners trying to attract pollinators might want to start with this mint-family perennial that was the top pollinator-attracting plant in Penn State University trials. Clustered mountain mint grows about three feet tall, produces pinkish-white flowers most of the summer, and has a minty fragrance. Best in full sun.

Abelia ‘Little Richard’

   ‘Little Richard’ is a tried-and-true, deer-resistant, compact, rounded shrub that produces tubular white flowers for months, starting in late spring. Leaves are semi-evergreen. Plants grow three to four feet tall and wide in sun or part shade.

American holly ‘Maryland Dwarf’

Holly ‘Maryland Dwarf’

   This evergreen is a native holly with spiny, glossy leaves, but it doesn’t grow anything like the tall-tree form that’s most familiar. ‘Maryland Dwarf’ is actually a low, spreading, berry-producing female holly that grows only about three feet tall but with a spread of 10 feet or more. It does best in moist soil and full sun to part shade.

Maple Autumn Blaze

   This fast-growing shade tree is a cross between two native maples (silver and red maples), and like most maples, is most regarded for its brilliant red-orange fall foliage. Autumn Blaze is a reliable and largely trouble-free variety that can grow about 60 feet tall and 40 feet wide. Best in full sun.

Kousa dogwood Scarlet Fire
Credit: Rutgers University

Kousa dogwood Scarlet Fire

   Decades in the works at Rutgers University, this new variety of Kousa (Chinese) dogwood tree is distinctive for its rich pink late-spring flowers. It also has red fall fruits, deep-red fall foliage, decorative flaking bark, and excellent disease resistance. Grows about 25 feet tall and 20 feet wide in sun or part shade.

(Disclosure: The author is a member of the Gold Medal panel.)

Green Ribbon Native Plants

   This program, run by the staff and Horticulture Committee at Jenkins Arboretum and Gardens in Devon, Pa., focuses on singling out some of our region’s best native plants for home landscapes.

When to Plant Which Edibles?

March 15th, 2022

   One of the tricky parts about vegetable gardening is knowing exactly when to plant each crop.

Some plants are best direct-seeded into the garden, others are best grown from transplants.

   Some need to go in the garden early so they’re done and ready by the time the weather gets hot.

   Others will croak if you plant too soon.

   Still others have two different planting windows, and a few can be planted successively throughout the season.

   Also important is knowing which crops do best when direct-seeded into the ground vs. being started from a store-bought transplant or a young plant you’ve started inside from seed over winter.

   Here’s a crop-by-crop calendar – geared to the Harrisburg area and based on my 40 years of veggie-growing experience – to help you know the ideal timing and seed/plant preferences of our most popular edibles:

   Basil: Direct-seed or plant transplants from mid-May through end of July.

   Beans, dill: Direct-seed from mid-May to end of July.

   Beets: Direct-seed from early April to end of July.

   Broccoli: Plant transplants in April early-summer harvest and again from mid-July to mid-August for fall harvest.

   Brussels sprouts, cauliflower: Plant transplants in April for early-summer harvest and in July for fall harvest.

   Cabbage: Plant transplants from third week of March through April for summer harvest and mid-July through mid-August for fall harvest.

   Cantaloupes, watermelon, pumpkins: Direct-seed or plant transplants from mid-May through mid-June.

   Carrots: Direct-seed between early April and end of July.

   Chard: Direct-seed between mid-April and mid-July.

   Collards: Direct-seed April through May for summer harvest and again in July for fall harvest.

   Corn: Direct-seed from early May through end of June.

Going Native with the “Wild Ones”

March 8th, 2022

   If you’re interested in native plants, a new chapter of a national native-plant group is taking root in 11 counties around south-central Pennsylvania.

Bill and Jane Allis are spearheading a local chapter of Wild Ones.

   The group is known as the “Wild Ones,” and it’s a Wisconsin-based not-for-profit that aims to encourage people to plant more native plants in their yards.

   The local effort is being spearheaded by Bill and Jane Allis, a retired couple who opened the semi-public, 36-acre Bower Native Plant Garden and Sculpture Park last year in Perry County.

   The new South Central Pennsylvania Chapter of the Wild Ones met for the first time online via Zoom last week. It’ll meet monthly and feature native seed and plant swaps, field trips to native-plant gardens and nurseries, and educational resources on native plants.

   The national group was founded in 1990 with the aim of promoting “environmentally sound landscaping practices to preserve biodiversity through the preservation, restoration, and establishment of native plant communities.”

   Its motto is “healing the Earth, one yard at a time.”

   Including the new South Central Pennsylvania chapter, Wild Ones now has 67 chapters in 26 states, plus 19 more “seedling” chapters in the process of forming.

   Prospective members can join by going to the Wild Ones “Join Now” page and selecting the membership-type drop-down box. Annual household memberships begin at $40.

   Jane Allis, who’s president of the new local chapter, said residents can still participate in the group and its activities without becoming an official Wild Ones member.

   The local group next plans to meet, in person, on Sun., March 27, at 2 p.m. at The Bower for a session on end-of-winter native-plant care.

   It’ll also meet Mon., March 28, at 7 p.m. via Zoom for its regular monthly meeting. Meetings are to be held the last Monday of each month.

   The South Central Pennsylvania chapter will cover Dauphin, Cumberland, Lebanon, Adams, York, Perry, Juniata, Mifflin, Huntingdon, Franklin, and Fulton counties.

   More information is available by emailing Allis at wildonesscpa@gmail.com or by visiting the chapter’s Facebook page.

The Best – and Worst – Times to Do Things Around the Yard

March 1st, 2022

   Some gardening jobs can be done most any time.

Cutting the ornamental grasses with a power trimmer.

   But others need to happen at certain times if you don’t want to, say, freeze your tomatoes by planting them too soon or cut off your hydrangea flowers by pruning them at the wrong time.

   As we approach another new gardening season, it’ll help to know when to do what. Here’s a look at the best times and worst times to do a dozen key tasks in Pennsylvania yards:

Pruning

   Best time: For spring-flowering trees and shrubs, right after they’re done blooming. For summer-flowering trees and shrubs, first thing in early spring. For shade trees, late winter when leafless. For evergreens, early spring through mid-summer.

   Worst time: Fall. Everything should be left alone to prepare for winter’s cold then. Plus, you’ll cut off the already-formed flower buds for next year by pruning spring-blooming shrubs and trees in fall.

Fertilizing

   Best time: Spring and early fall – right before periods of good growth.

   Worst time: Any time the ground is frozen and during hot, dry weather in summer.

Planting

   Best time: For woody plants and perennials, end of March through May and between Labor Day and end of October in fall. For frost-sensitive annuals and vegetables, mid-May through early summer.

   Worst time: Winter and during a heat wave in summer. For borderline-hardy species, spring is a better time to plant instead of fall (more time for the roots to take hold).

Digging soil

   Best time: Spring – after the soil has dried. Or any time in summer or fall.

   Worst time: Any time the soil is wet or frozen.

The Latest in Gardening Research: Hedge-Trimming Robots, Super Roots, and Milkweeds of the Future

February 22nd, 2022

   Let’s catch up this week on some of the latest gardening research that might impact how we grow…

The European TrimBot2020.
Credit: Elsevier/ScienceDirect

A Hedge-Trimming Robot?

   We already have robots that vacuum our floors, mow our lawns, and even weed our gardens, so is a robot that trims our bushes and hedges next?

   Researchers in Scotland, the Netherlands, Germany, and Switzerland are evaluating a prototype hedge-trimming robot called the European TrimBot2020 that’s a wheeled machine fitted with eight cameras and a robotic arm with trimmers at the business end.

   In its first European real-world trial, TrimBot2020 was assigned to trim boxwoods into three different shapes – spheres, cylinders, and cubes.

   The initial results were underwhelming, according to a paper in this month’s issue of Biosystems Engineering.

   In both 3D computer assessments and evaluations by 10 humans, the best rating TrimBot2020 could muster was 3.1 out of 5.

   “The poor trimming performance, in particular for cylindrical and cuboid shapes, indicates that the trimming result of the mobile robot is not yet accurate enough for practical application of trimming complex shapes,” the researchers concluded.

   They added that the trial was helpful, though, in identifying “bottlenecks and weak points” to tweak TrimBot’s future performance.

   Automated plant-trimming machines already are used in some nursery productions, but those use GPS to trim mechanically without any sensory feedback.

   The trick in developing a robot for garden settings is figuring out how to navigate varying terrain and how to have a robot assess how it’s doing as it manipulates the bushes into the desired shapes.

The Quest for Bigger, Better Roots

   Research that turned out more promising came from Penn State University, where researchers isolated a genetic trait in corn and wheat that causes their roots to penetrate better into compacted soil. The trait could lead the way to new varieties that grow and yield better.