Bleeding Heart Perennial

The term bleeding heart perennial actually refers to two different types of groups of flowering plants. The most common and famous one in the United States is the Dicentra group. The other one is the Clerodendrum group.

The Dicentra group is formed of 20 species, and most of them are known as bleeding heart perennials, except that each one has an extra name to it. For example, the wild bleeding heart perennial, the fringed bleeding heart perennial, the western bleeding heart perennial and the pacific bleeding heart perennial. The reason why this group is much more famous is because all the species are native to North America.

All of these flowering plants are greatly appreciated for their flowers. They are very beautiful and appropriately named. The flower is shaped in the form of a heart, and the petals make it seem like there is a drop of blood descending through it. The color of the flower is pink, although there are some species which give flowers that are white.

All flowering plants of the Dicentra group are perennials. That is, they live two years or more, as opposed to annual flowering plants, which only live one year, and usually die in winter. Dicentra flowering plants are planted only once, and they can survive winter provided they are planted in their appropriate hardiness zone, as established by the United States Department of Agriculture.

There is one last thing about the Dicentra flowering plants that you need to know. All parts of the Dicentra flowering plants are poisonous. So, if you have small children, you have to educate them so they understand that the pretty flowers are not edible, no matter how attractive they look.

The other type of bleeding heart perennials is the Clerodendrum group. This type of bleeding heart perennial is native to tropical Africa and southern Asia, and thus they’re not very well known in the United States. However, they can survive in tropical and warm temperate regions.

The Clerodendrum group is much bigger than the Dicentra group. It has about 400 species of flowering plants. Also, unlike the Dicentra group, the Cleodendrum group is much more varied. While all plants of the Cleodendrum group flower, some of them are shrubs, others are lianas and some are even small trees, which can grow up to 12 meters tall.

Because of the varied type of plants of these, they’re not used much for decoration. If that’s what you want, I suggest you get the American ones. They’re much easier to find anyway and they make more justice to the name Bleeding Heart Perennial.

Answers to your gardening questions and other tips by George Weigel.

02/28/2010 06:00 PM

George's Talks and Trips 2010

George has an exhausting list of talks, bus trips and even full garden-themed vacations to Ireland, South Africa and Holland's Floriade in the works. See the full schedule here...

When he doesn’t have his nose in a computer or compost pile, Patriot-News garden writer George Weigel is out and about doing gardening talks and leading garden-themed trips.

New for 2010 are talks on “Great Gardens, Less Work,” “Survivor Plants,” “Cutting-Edge Plants for Your 2010 Garden” and “10 Ways to Be a Greener Gardener,” among many other holdovers. See the lineup below for programs that are open to the public.

If you like to ogle gardens, George and Lowee’s Group Tours of Harrisburg are putting together the best lineup yet of monthly garden trips. Most will be day trips (Philadelphia Flower Show, Alexandria's Home and Garden Tour, Annapolis, “Plant Nerd Excursion” to Bucks County, etc.), but three are overnighters (Niagara Falls/Garden Walk Buffalo, Gardens of Long Island, Williamsburg, Va.)

Then there are several garden vacations where you can join George, his lovely wife, Sue, and other local gardeners on trips to some of the world’s best plant destinations.

A 9-day June 2010 trip to see the Gardens of Ireland is already sold out (sorry), but Harrigan Holidays is offering a sequel to Gardens in Northern Ireland in June 2011.

In January of 2011, George and Harrisburg Area Community College are offering a 2-week trip to South Africa that will feature stops at the Kirstenbosch, Harold Porters and Pretoria botanic gardens, DeHoop Nature Reserve, the country’s famed Garden Route, Victoria Falls and more.

And in April 2012, George and Lowee’s are planning a trip to see the eye-popping Floriade in Holland, which is a multinational Olympics of Gardening that’s held only once every 10 years.

Details are below...

GEORGE’S 2010 TALKS

* Sun., March 7, 12:30 p.m. “Gardens for All Four Seasons.” One of the nicest features of central Pennsylvania’s climate is how our plants and landscapes change with each of the four distinct seasons. Take advantage of this beauty by planning your yard so it looks good throughout the year. Besides strategies, we’ll look at some of the best plants for each season as well as “horticultural hard-workers” that do more than one thing in one season. At Christ Evangelical Lutheran Church, Linglestown. $25. To register: Call Harrisburg Area Community College at 780-2414 or 780-2616 or visit online at HACC’s Continuing Education web site at http://vc.hacc.edu.

* Sun., March 7, 3 p.m. “How NOT to Mess Up Your Landscape.” This program shows the right way to care for a yard by looking at examples of the wrong way. (You might even see pictures of your own yard!) We’ll take a fun look at real-life examples of common landscape foul-ups, then learn how to sidestep those problems. It includes foibles in design, plant selection, maintenance and gardening in general. At Christ Evangelical Lutheran Church, Linglestown. $25. To register: Call Harrisburg Area Community College at 780-2414 or 780-2616 or visit online at HACC’s Continuing Education web site at http://vc.hacc.edu.

* Sat., March 20, 9:30 a.m. “Great Gardens, Less Work.” George will be speaking on work-saving in the garden in this program, which is part of the Fifth Annual Dauphin County Master Gardener Spring Workshop Series. Working long and hard doesn’t guarantee you’ll end up with a beautiful landscape. Working smarter is a better way to get results without wearing yourself out. Among the strategies we’ll cover: better plant selection, getting the right plant in the right place, preventing problems rather than reacting to them, and simplifying necessary jobs while eliminating unnecessary ones. At Dauphin County Extension Office, 1451 Peters Mountain Road, Dauphin. $6 in advance or $10 at the door. Registration information: Call 921-8803 or email DauphinExt@psu.edu.

* Sat., Oct. 2, 10 a.m. “10 Ways to Be a Greener Gardener.” Gardeners should be leading the pack when it comes to caring for the environment. This program -- in the heart of prime fall-planting season -- offers a range of enviro-friendly practices that also make good gardening sense, such as rain gardens, rain barrels, composting, spraying less, making smart plant choices and more. Free, with percentage of plant sales that day going to Channels Food Rescue in Harrisburg. At Meadowood Nursery, 24 Meadowood Drive, Hummelstown. More information: www.meadowoodnursery.com or 566-9875.

BUS TRIPS WITH GEORGE
These one-day and multi-day excursions target some of our region’s best and often little-known public gardens. Each trip includes traveling seminars and timely gardening tips, plus gardening games and prizes that may land you a plant or two from George’s gardens. Most trips also feature a stop at a distinctive garden center on the way home. Bonus: George’s fun, friendly and beautiful wife, Sue, will be the escort on most of these trips and serve as your “mom” for the day.

Bring your gardening questions! George is happy to answer every last gardening question until he collapses at the end of each trip.

Buses leave from East Shore and West Shore locations, and trips are planned and operated by Lowee’s Group Tours of Harrisburg (717-657-9658, toll-free 1-888-345-6933, www.lowees.com or email ckelly@lowees.com). Details also are on George’s web site at www.georgeweigel.net.

· Sat., April 17: Historic Home and Gardens of Alexandria

Quaint and Colonial Alexandria, Va., hosts one of our region’s most popular home and garden tours. Each April, the townspeople open about a half-dozen historic homes and their gardens to visitors. You’ll have all afternoon to explore them and walk Old Town Alexandria. We’ll spend the morning seeing the house and gardens at River Farm, one of George Washington’s original five farms along the Potomac. Dinner at Clyde’s Restaurant on the way home is included. $137 (or $102 if you don’t want the home and garden tour pass). (717-657-9658, toll-free 1-888-345-6933, www.lowees.com or email ckelly@lowees.com)

· Fri., May 14: “Plant Nerd Excursion” to Bucks County

So you like to plant shop, eh? Here’s a whole day in the heart of prime planting season geared toward haunting some of Bucks County’s finest garden centers with George on hand to help you pick.

First up is Hortulus Farm and Gardens near Newtown. We’ll start with a guided tour of the place’s 20 theme gardens, then check out the cutting-edge annuals and tropicals at this connoisseur’s nursery. This is where Chanticleer Gardens gets many of its plants.

After lunch at the Lambertville Station, we’ll head over to Bucks Country Gardens, a large, full-service and upscale garden center that features everything from pots to statues to fertilizers in addition to plants.

Then it’s on to Linden Hill Gardens, a combo garden center and display gardens with a huge perennial garden planted and cared for by horticulturist/author Nancy Ondra. All of the latest, greatest plants are here and displayed elegantly around a stone barn. Both Linden Hill and Bucks Country Gardens are giving us 10 to 20 percent discounts. $119 per person. (717-657-9658, toll-free 1-888-345-6933, www.lowees.com or email ckelly@lowees.com)

· Fri., June 11: William Paca House and London Towne Gardens, Annapolis, Md.

The morning stop is at the William Paca House, a Georgian-style mansion dating to the 1700s and built by a signer of the Declaration of Independence. The gardens are formal, elegant and terraced.

After lunch at Annapolis’s Chart House, we’ll stop to see the Helen Avalynne Tawes Garden, a 5-acre garden showcasing the different flora of Maryland, such as shore plants, streamside vegetation, forests, and so on.

Next is Historic London Town, a 23-acre park and museum with extensive gardens, including a woodland garden, a Colonial kitchen garden, native-plant beds and mixed gardens.

The last stop is Homestead Gardens -- one of the nation’s best and most respected garden centers. Besides a wide offering of various plants, Homestead has a huge garden shop and a petting zoo with llamas. We’ll get 15 percent off purchases, too. $114 per person. (717-657-9658, toll-free 1-888-345-6933, www.lowees.com or email ckelly@lowees.com)

· July 21-25: Sonnenberg Gardens, Niagara Falls and Garden Walk Buffalo

This one’s a 5-day gardener’s summer vacation with plants, wine, waterfalls and more. I think it’s the best trip we’ve put together yet. It’s packed with all sorts of interesting and varied attractions.

Day 1: Stop at Sonnenberg Gardens in the heart of New York’s Finger Lakes region. We’ll tour the nine formal gardens, greenhouse complex and 1887 mansion, eat at the High Noon Café, and take time for a wine-tasting. Then we’ll stay overnight at the Marriott Courtyard in Niagara Falls, Canada.

Day 2: Explore the beauty of Niagara Falls, including great views of the falls from the Oakes Garden Theatre, a walk through Queen Victoria Park, a journey behind the Canadian Falls and a stop at the Floral Showhouse, a greenhouse display just south of the falls. Lunch is included at the brink of the falls, and dinner is included atop the Skylon Tower.

Day 3: Niagara Garden Trail day. The first stop is a drive out Niagara Parkway to see the Niagara Parks Botanical Garden with its 99 acres of gardens, arboretum and the Butterfly Conservatory. We’ll also see the famed Floral Clock, which is an actual working clock surrounded by 16,000 annual flowers. After lunch along the Niagara River in Queenston, we’ll tour the McFarland House, site of “Canada’s Best Tea Garden.” We’ll cap the day with a ride on the Maid of the Mist boat.

Day 4: Drive down to Buffalo, N.Y., for this weekend’s “Garden Walk Buffalo” -- America’s largest private garden-tour event. Some 340 residents of Buffalo open their gardens for all to see. Most are within walking distance, as is the Urban Roots Community Garden Center, the Delaware Park Rose Garden, the Erie Basin Marina University Test Gardens and the Buffalo Japanese Garden. Overnight in Buffalo.

Day 5: We’ll tour the Buffalo and Erie County Botanical Gardens in the morning, then stop for lunch and some time to tour the glass-blowing museum in Corning, N.Y. Dinner is included in Trout Run, Pa., and we’ll be home by early evening. $899 per person. (717-657-9658, toll-free 1-888-345-6933, www.lowees.com or email ckelly@lowees.com)

· Fri., Aug. 20: Burpee Fordhook Farm, Schmieder Arboretum, Michael Petrie’s garden center

Stop 1 is Burpee’s “Harvest Festival,” which features tours of the 60-acre Burpee vegetable trial grounds, talks and a tomato-tasting at the historic Fordhook Farm in Bucks County. The grounds also include display gardens of Cooks Garden and Heronswood Nursery plants.

After lunch, we’ll tour the Henry Schmieder Arboretum and other plant displays on the campus of Delaware Valley College, a school with one of our region’s top horticulture programs.

Then we’ll visit Michael Petrie’s Handmade Gardens, a brand-new and very original garden center founded by the creative genius who wins the top display-garden awards most years at the Philadelphia Flower Show. Dinner included at Firecreek Restaurant on the way home. $99 per person. (717-657-9658, toll-free 1-888-345-6933, www.lowees.com or email ckelly@lowees.com)

· Fri., Sept. 24-Sat., Sept. 25: The Gardens of Long Island

Four main venues on this 2-day, 1-night trip to New York’s Long Island. We’ll start with the 200-acre Old Westbury Gardens, an early 20^th-century estate with a series of formal gardens, wooded gardens, ponds, trees and a 1906 mansion.

Then it’s over to Planting Fields Arboretum State Historic Park, which encompasses 409 acres in trails, woodlands and great landscaped gardens, all designed by the famous Olmsted brothers.

Day 2 will feature a visit to Madoo Conservancy, a 2-acre “artist’s garden” designed by artist John Dash. We’ll see some interesting combinations and surprises here.

The last stop is at Landcraft Environments, a nursery with display gardens that specializes in exotic, unusual and tropical plants. $339 per person, including lodging, four meals and all admissions. (717-657-9658, toll-free 1-888-345-6933, www.lowees.com or email ckelly@lowees.com)

· Fri., Oct. 15: Longwood Gardens -- Behind the Scenes

Most gardeners have seen the world-class, 1,000-acre Longwood Gardens the “usual” way, but this day is aimed at seeing Longwood from the inside out. We’ll spend the day with Longwood staff seeing what they do behind the scenes -- what’s underneath the $25 million conservatory, the “backup” plants in the staff nursery, how the grounds are kept in immaculate condition and more. We’re still working on the final details. Cost not yet determined. (717-657-9658, toll-free 1-888-345-6933, www.lowees.com or email ckelly@lowees.com)

· Dec. 6-9: A Green Williamsburg Christmas

Williamsburg, Va.’s annual “Grand Illumination” is a glorious site in itself, but we’re adding a garden twist. We’ll start this 4-day get-away with an orientation tour of Williamsburg’s restored area and have dinner at the colonial King’s Arms Tavern. We’ll stay at The Woodlands, lodging in a pine grove located conveniently next to the visitor center.

Day 2 will feature a guided walk focusing on how Williamsburg’s staff uses natural materials to make great holiday decorations. That afternoon, we’ll attend a demonstration on how to make some of these creations at home, followed by free time to visit the restored area.

Day 3 is garden day, where we’ll spend time with a staff garden historian learning about how people gardened in Colonial times, followed by a walk focusing on the gardens and then lunch at Shields Tavern. In the afternoon, we’ll hear Dean Shostak perform holiday favorites on the rare glass harmonica, a beautiful instrument invented by Benjamin Franklin.

Day 4 is a stop at one of the most underrated public gardens, the Lewis Ginter Botanical Garden in Richmond. We’ll tour the gardens, visit the large conservatory and have a buffet lunch in the Ginter café before heading home. $599 per person, including 3 nights lodging, six meals and all admissions. (717-657-9658, toll-free 1-888-345-6933, www.lowees.com or email ckelly@lowees.com)

2011 GARDEN TRIP TO SOUTH AFRICA

Harrisburg Area Community College is teaming up with George and Sue for a 17-day garden get-away to glorious South Africa from Jan. 11 to Jan. 27, 2011. South Africa has been described as the Land of Oz when it comes to horticulture for its huge amount of botanic diversity. It’s a country also rich in wildlife and natural resources.

We picked January because it’s summer in South Africa – a great time to burn off more than two weeks of central-Pennsylvania winter. Planned by AAA through General Tours World Traveler, this trip flies into Capetown and returns from Johannesburg, with a side trip to see the magnificent Victoria Falls from the Zambian side.

Garden destinations will include Kirstenbosch National Botanical Gardens, Harold Porters Botanical Gardens, Karoo Desert Botanical Garden and Pretoria National Botanical Gardens.

Other stops along the way will feature Capetown’s Table Mountain, Hout Bay, the Cape of Good Hope Nature Reserve, the Cape of Good Hope, a tour of the Winelands region (including Stellenbosch, Paarl and Franschhoek), DeHoop Nature Reserve, a drive along the Garden Route coastline, the Knysna and Milkwood forests, the Kruger House Museum, Northern Kruger National Forest, the Pafuri Camp Game Reserve and Victoria Falls.

All of the details are available by calling HACC’s Continuing Education office at 780-2444 or emailing Dr. Donald Koones at dgkoones@hacc.edu.

2011 GARDEN TRIP TO IRELAND
George and Sue will lead an 8-night, 9-day trip to Ireland June 18-26, 2011, in conjunction with Harrigan Holidays of East Berlin, Adams County.

Garden visits will include the Belfast Botanic Gardens, Mount Stewart House and Gardens, Benvarden Gardens, Ballydaheen Gardens, Glenveagh National Park/Castle and Gardens, Lissadell House and Gardens and Kylemore Abbey and its Victorian Walled Garden.

Tucked in among the garden stops will be visits to Irish landmarks and attractions such as a Belfast city tour, the Down Cathedral, the Down County Museum, the Antrim Coast, Giant’s Causeway, Magees of Donegal (famous for Donegal tweed), the Carrowmore Cemetery, the Connemara Marble Factory, a 2-hour Gaelic cultural program at Cnoc Suain, the Cliffs of Moher, the Ards Peninsula and the Burren Perfumery and Floral Centre.
Destinations include Belfast, Derry, Donegal, Galway and Limerick.

The cost is $2,990 per person, including airfare, three- and four-star hotels, daily breakfasts and all but one night’s dinners as well as all admissions.

For more information, contact Kathy Harrigan at 717-818-3024 or email ksharrigan@verizon.net.

2012 GARDEN TRIP TO HOLLAND’S FLORIADE

   Lowee’s Group Tours is organizing a trip to the Netherlands in April of 2012 to see the amazing Floriade gardening show. This happens only once every 10 years, and is akin to an international Olympics of gardening. Some of the best growers, plant companies and designers from around the world build flowering outdoor exhibits in a different section of Holland every 10 years. The sites then become public parks. It’s a must-see if you’re a crazed gardener who also likes to travel.
   We’ll also see the famed Keukenhof Gardens in Lisse, which is open only in April and May and is acres and acres filled with the most amazing bulb displays you’ll ever see. More details once bookings are ready.
   In the meantime, learn more about this show at www.floriade.com (select the English version from the drop-down box unless you’re fluent in Dutch). The 2012 Floriade will be held in the Venlo region of The Netherlands, in the southeastern part of the country near the Dutch/German border.
   To get on the list for this trip, contact Lowee’s Group Tours at 717-657-9658, toll-free 1-888-345-6933 or email ckelly@lowees.com.

03/10/2010 06:13 AM

Transplanting bulbs

Wait until after your spring bulbs have flowered if you need to move them -- and ideally after the leaves have started to brown. Moving them now may abort or shorten this year's bloom.

bulb.move2.jpg George WeigelIt's best to transplant bulbs after they've flowered -- and ideally once the leaves are browning. Q: I would like to know that if during this warm weather, would I be able to transplant Japanese irises, hyacinths and tulips that are emerging now? Would it kill them or hurt them? What if I would cover the emerging plants with a sheet during the night after I transplanted them?

A: I’ve moved emerging and even blooming bulbs already, but you always run the risk of aborting or at least shortening the bloom time. It isn’t the cold that’s the problem so much as the act of disturbing the roots at a time when the plant is working on flowering.

If you can wait, you’re much better off moving the bulbs after they’ve flowered and especially once they’ve at least started to die back for the summer.

Some people think you have to wait until fall to transplant bulbs, but you’ll have just as much success replanting the bulbs in their new home immediately after digging them. The advantage of doing it as the foliage is browning is that you know where the bulbs are. Come fall, you’ll be guessing.

Either way, be careful not to slice into the bulbs while digging. Once you split them, they’re dead.

03/09/2010 06:57 AM

Vole ruts in the lawn

Surface tunneling in the lawn is the work of voles, not moles. Moles leave behind raised ridges and volcano-like exit holes. Voles make golfball-sized holes down into the ground and tunnel across the lawn surface under cover of snow.

lawn.vole.trails.JPG George WeigelSurface tunneling damage in the lawn done by voles. Q: Is it possible to have mole activity already? I have numerous 1½-inch holes in sections of my yard and even have what looks like a 2-inch rut that runs about 6 feet on top of my yard and into an area that appears to have been chewed up. What can I do to control this?

A: That sounds more like vole damage than moles. Moles make mounded exit holes that look like little volcanoes and tunnel under the surface to make raised pathways. Voles make holes the size of a golfball that go down into the ground, and their activity leaves narrow, curving ruts over the lawn surface.

Voles had a great winter. These small, seed- and root-eating rodents don’t venture out in the open lawn during the growing season because hawks and predator birds swoop down on them. But under snow cover in winter, they can wander all over, eating grass roots and making those surface ruts.

Now that the snow is gone, the tunneling will stop. Voles will stick to their growing-season homes under shrubs and groundcovers and along walls.

Rake off the dead turf and scatter a little grass seed and soil in the damaged areas. Given a few weeks of growing time, lawns are pretty good at repairing themselves even if you just rake away the brown and skip the seeding.

Mouse snap traps or cage traps baited with peanut butter are fairly effective at capturing voles. The best solution, though, is having a cat on patrol.

03/08/2010 07:53 AM

Browned-out hosta

Some hostas will brown out when they get too much sun. Moving them to a shadier spot often solves the problem. Excess soil salt or one of several diseases also can cause foliar browning.

George WeigelHosta that's getting a little too much sun. Q: Every year my hostas turn brown by the end of the summer. Is there anything I can do to prevent that this year?

A: Early this spring before new growth starts, try moving them to a shadier spot. My leading guess is that they’re frying in a too-sunny location. Are they out in the open or in an afternoon-sun spot?

The thin-leafed, white-margined types are particularly prone to browning around the edges in summer’s heat and sun.

Salty soil sometimes can cause or contribute to this. I’d be suspicious of that if the hostas are along a road where they’re getting hit by winter road-salt spray or along sidewalks where they’re getting salty runoff from salt-based ice melters.

Hostas are usually pretty durable plants, but they can get one of several fungal, bacterial and viral diseases. Most of these start out as spots, but the spots can coalesce into brown splotches. If that’s what you’re getting moreso than browning around the leaf edges, here’s a good web page from Iowa State Extension that has pictures and treatments of hosta disease: www.extension.iastate.edu/Publications/sul14.pdf.

03/05/2010 06:32 AM

Pruning pyracantha

Pyracantha can be pruned heavily at end of winter, but you'll sacrifice all or most of the flowers (and ensuing fruits). Another option is to prune lighter and selectively just as the bloom is winding down. Then you can be sure to let behind some flower clusters that will fruit.

George WeigelA pyracantha with an ample supply of fall fruits. Q: I have a large firethorn (pyracantha) planted between small foyer windows. The plant last year did not have many blooms, and the berries were small and wrinkled. The plant needs a serious trimming as it is growing over both windows. How hard can this plant be trimmed back and when?

A: Pyracantha can be trimmed back almost to nothing, and it’ll push out new shoots, including from the base. It’s a survivor – and its sharp thorns make it good on offense, too.

End of winter (before leaf-out) is a good time to do major shaping and significant cutbacks. It helps to cut back to joints (where two branches meet or where an unwanted side shoot attaches to the trunk). But I’ve seen pyracantha mercilessly decapitated with power shears, and it still looks fine a few weeks later.

Heavy pruning will control the plant, but you’ll give up all or most flowers since pyracantha flowers on buds formed the fall before. No flowers mean no fruits later. So it’s the unpruned and lightly pruned plants that actually flower and fruit best.

If you need to both prune and want at least some flowers, wait until later in the spring after the plant has flowered. As the flowers are winding down, thin out excess branches and shorten branches and side shoots as much as you can while leaving behind as many flower clusters as you can. This timing lets you see what you’re cutting off so you can make informed choices.

Shriveled berries are usually a sign of disease. Pyracantha are particularly prone to scab and sometimes to a bacterial disease called fireblight. Spraying fungicides is usually needed to prevent scab, while there’s not much you can do about fireblight except prune out killed branches.

Lack of light, a late freeze and out-of-whack soil nutrition are three other reasons why a pyracantha might not bloom well (in addition to heavy winter or early-spring pruning).

03/04/2010 10:21 AM

How do shows get flowers to bloom?

It might not be nice to fool Mother Nature, but it’s a good thing the garden shows do anyway.

We really needed the sneak peek of spring given to us by last weekend’s Pennsylvania Garden Expo (Farm Show Complex, Harrisburg) and this week’s Pennsylvania Home Show, Philadelphia Flower Show and Mid-Atlantic Garden Show in York.

The tulips and rhododendrons already are in full bloom inside these shows — if only for a few days. How do they do it?

Most non-gardeners assume there’s a spray or treatment that growers use to magically produce blooms on demand.

Actually, it’s a part-skill, part-educated-guess technique called “forcing” that results in blooming azaleas weeks ahead of nature’s schedule.

Forcing involves waking plants from dormancy early by taking them into a heated greenhouse.

Give them just the right amount of heat, just enough light and time it just right, and you can control when those buds pop ... to some degree.

Basically, it’s faking the plants into thinking it’s already April or May.

“Witch hazel, rhododendrons, forsythia and early-spring bloomers are pretty predictable,” says Joe Levendusky, who grew most of the plants for his company’s display garden at last weekend’s expo. “But even things that bloom later in spring, they’re hard.”

Summer bloomers are possible but even more difficult — usually requiring cold pre-treatments, mechanically monitored heat and light and a long lead time.

Plus a little luck.

Since most shows run for only a few days, the margin of error is slim.

“If you’re even two weeks off, you get to watch the last petals fall off,” Levendusky says.

Nye’s Nursery and Landscape of Grantville had trees for its expo display in a wood-heated greenhouse on Jan. 1.

Azaleas and rhododendrons need 4 to 6 weeks of lead time to flower at show time, but forsythia needs only 2 weeks.

"Over time, we’ve learned how long it takes to force different plants,” says co-owner Matt Nye. “Then you count back from when you need it.”

And you hope that fluctuations in outdoor temperatures and sunlight don’t throw off the calculations too much.

Not all of the landscapers force their own plants.

Most of the bulbs, pansies and primroses are grown by commercial greenhouses that grow just for these shows. These tend to be much more expensive, though, than equivalent plants in season.

Evergreens are a little easier. They can be dug with a tree spade, wrapped in wire baskets and burlap and dropped into place on the concrete floor with nary a whimper. Within days in the warmth, they green up.

That was a little more difficult this year because the landscapers had to dig through 2 feet of snow first just to get to the soil.

Smaller potted evergreens usually don’t mind moving from unheated greenhouse to show floor, although Levendusky says hollies resent it by browning around the edges.

Levendusky tapped into another plant family to add life to his 2010 display — colorful tropical houseplants such as croton, cordyline and snake plants.

These were easier because the color comes from the leaves, not from flowers that have to be forced.

Almost all plants are left in their pots and sunk into mulch as is. Mulch is pulled up to hide the pot lips.

Most plants can be salvaged after the shows, stored in greenhouses and planted outside in “real” spring, although they won’t bloom again until the following season.

As for the expo gardens themselves and their elaborate water features, those are all built in four days on top of flat concrete.

That’s not easy either.

“I’ll admit it was overwhelming when I found out we couldn’t get started until Monday afternoon,” said John Reinford, whose Newville-based Reinford Landscapes built its first indoor display garden and ended up winning best of show. “There were skid loaders, dump trucks and people everywhere. We had our rectangle marked off in tape. It took us a little to get our bearings, but then stuff started happening.”

Boulders, big trees and the stonework for water go in first. Hills and contours are built by stacking and packing stone dust — finely crushed limestone.

Then the rubber liners, pumps, pavers and smaller stone are added.

Levendusky says a lot of show-goers think the waterfalls are fed by constantly flowing water from a hidden pipe that sends the water down a drain in the pond.

“They don’t realize that these are all closed systems that recirculate,” he says.

One of the testiest moments is when the ponds are filled with water.

“If you poked a leak in your liner, then you have water over the whole show floor,” Levendusky says. “That’s happened already.”

Finally, mulch goes over the stone dust and the remainder of the floor, and the plants are inserted.

Instant spring.

SEE THE SHOWS:
Philadelphia Flower Show: now through Sunday at Pennsylvania Convention Center in Philadelphia. www.theflowershow.com.
Mid-Atlantic Garden Show: today through Sunday at Toyota Arena, York Fairgrounds. www.midatlanticgardenshow.com.
Pennsylvania Home Show: open Saturday through March 14 at Pennsylvania Farm Show Complex. www.pahomeshow.com.

03/04/2010 06:46 AM

Veggie garden going downhill

Small vegetable gardens can suffer a build-up of disease and a drawn-down of nutrients over the years, resulting in what farmers used to call "tired soil." If you'd rather not let the ground go fallow for a year or two, there are other steps to try.

myyard.sad.tomatoes.JPG George WeigelMy own tomato planting last year, decimated by blight and septoria leaf spot. Q: I have a 10-by-15-foot vegetable garden that I started about 10 years ago. I had lush growth and abundant peppers, tomatoes and other vegetables for the first 7 years. But the last 3 years, the tomatoes in particular die from the bottom up. The leaves develop spots, turn yellow then grayish brown, and dry up.

My cucumbers also struggle. I think they’re getting mildew on the leaves. The garden is not very big and is fenced in. There is really not much room to rotate crops. Do you have any suggestions?

A: That’s actually a very common problem with small gardens. Soil-borne diseases can build up, and nutrients can drain down if you’re not replacing them as fast as heavy feeders such as tomatoes, peppers and corn are using them.

In the old days, farmers called it “tired” soil. It’s what led to the idea of rotating fields so that part of the acreage would be left fallow every three or four years.

Unfortunately, that’s not practical for your “acreage.” Even in fairly large back-yard gardens, rotating crops from one spot to another only helps marginally – especially when it comes to disease.

A tomato disease such as septoria leaf spot (which it sounds like you’ve got) or early blight can easily jump to the opposite end of your 10-foot bed.

One solution would be to dig a new garden in another part of the yard and return your current garden to ornamentals or grass. I know that’s a lot of work, and yeah, I probably wouldn’t actually do it either.

The second effective-but-not-great idea is to let the garden rest for a year. Or better yet, plant a nitrogen-producing cover crop such as red clover, rye or hairy vetch. Till in the cover crop (a.k.a. “green manure”) the following spring and give the veggies a go again then. In the meantime, you could grow a few tomatoes and peppers in pots.

The most realistic idea is to take a series of steps to maximize soil nutrition and minimize disease. These would include:

1.) Top the soil each fall with an inch layer of compost.

2.) Test the soil and add the recommended fertilizers. The test also will tell you pH (soil acidity) and give instructions on whether you should add sulfur or lime to maximize growth.

3.) Go with the best varieties. See my web page at http://georgeweigel.net/favorite-past-garden-columns/edibles/variety-matters for a list of recommended top performers from Cornell University.

4.) Keep the garden weeded, well watered (water the ground, not over top of the plants) and mulched with clean straw or composted leaves.

5.) You’ll probably have to resort to fungicides to keep blight and septoria in check (copper and Bacillus subtilis, the pathogen in Serenade, are organic options).

6.) Don’t compost diseased foliage, rotate crops as best as you can, and if you’re not already doing it, build raised beds so you’re growing in loose and well-drained soil.

03/03/2010 05:49 AM

Black plastic underneath mulch

Black plastic as a weed control can do more harm than good -- particularly by shutting off oxygen flow to the roots. It's more useful underneath stones in a pathway.

George WeigelBlack plastic under a stone path is a better idea than in garden beds. Q: I’ve been trying to stop weeds by laying black plastic underneath my mulch. Every year or two, I pull it up and till, then put it back down. Is there any problem with doing that? It seems to help with the weeds, but it’s a lot of work

A: That’s for sure! I’m not a big fan of black plastic, except in the vegetable garden with a soaker hose or drip line underneath and in pathways underneath stone.

The main downside is that plastic reduces oxygen exchange in the soil. Roots need oxygen, so whether it’s excess water filling the air spaces or a plastic barrier shutting off the flow, less oxygen is bad news for plant growth.

Years and years ago in my “garden infancy,” I laid plastic down and planted a bed of groundcover junipers. They didn’t seem to be doing very well after a few years. When I uncovered an area, I found that the juniper roots had grown up and sucked onto the bottom of the plastic – almost as if they were gasping for air and crying, “Let me out! Let me out!”

Plastic is especially bad in clay soil, which doesn’t drain well to start with. The combo of reduced evaporation from excess moisture and reduced oxygen exchange is a plastic double whammy that can stunt or kill plants.

In dry weather, plastic doesn’t help either because when rain comes, it can only seep in around the openings where you’ve inserted plants.

Another problem… when mulch starts to break down over top of plastic mulch, weeds can germinate on top. That starts to happen the second or third year and gets progressively worse unless you keep adding more and more mulch. And if you’re going to do that, why bother with the plastic in the first place?

You’re short-circuiting this by removing the plastic and topping it with fresh mulch every year or two. That’ll do a great job at stopping weeds, but like you say, it’s a ton of work.

I’m not sure what benefit tilling would give you, other than possibly aiding aeration so long as you’re not tilling when the soil is wet. On the other hand, tilling will stir up buried weed seeds, disturb earthworm activity (you may even chop some of them up in the process), injure nearby plant roots and possibly harm the soil structure.

I think the best anti-weed strategy is 1.) plant so the plants you want touch, 2.) plant groundcovers under and between woody plants, 3.) keep 2 or 3 inches of bark mulch and/or chopped leaves over bare soil, and 4.) pull weeds that manage to pop up anyway when they’re young.

03/02/2010 06:33 AM

Cracked Hinoki cypress

We'll be seeing lots of cracked and split branches. Some of them may be salvageable by binding the splits back together -- even bolting them back together. Or just prune off bad splits and reshape the plant as best you can in spring.

broken.branch.boxwood.JPG George WeigelSnow-cracked branches like this are probably goners, but if there's enough attached to try binding and/or bolting, give it a shot. Q: I have a young Hinoki cypress that I just planted last spring. I was looking at it since some of the snow melted and noticed the top 6-8 inches of the main branch have broken/split from the weight of the snow. Please tell me how to save my little cypress bush.

A: Don’t worry. The break won’t kill your Hinoki. At worst, you’ll have to prune off the broken section and maybe do a little reshaping to get it back on track.

If it’s a clean split, it’s worth a try binding it back together. Use a piece of old nylons to wrap the pieces back together if the branch is the size of your pinkie or less. If it’s bigger, you can even drill a small hole and use a small galvanized bolt or two to hold the break together.

If the wood hasn’t calloused over already, it’s possible the split will fuse together. You’ll know by summer. If it’s green and putting out new growth, it worked. If it browns out, it’s dead. Then prune off the dead wood back to just above the next live shoot.

Pruning also is the way to guide the next most upright branch to become the new leader. Good luck!

03/01/2010 08:05 AM

Potted plants on a hot deck

Potted herbs and veggies like full sun, but they'll dry out quickly in hot-afternoon sun. Use big pots, group them together, water daily (or more) and work a few soil-absorbing polymer crystals in the potting mix at planting time.

George WeigelTom Jorich of Oberlin gets great (and good-looking) tomato yields by growing out of painted 5-gallon buckets. Q: I live in a condo where I get morning sun in the front and extreme sun on the rear deck in the afternoons. Through trial and error, I have found herbs grow best in the front and tropical plants grow best on my deck.

I have grown cherry tomatoes on my deck in a pot and in a hanging bag. The pot did a little better than the bag, which didn’t do very well at all. I would very much like to plant lettuce, tomatoes and possibly spring onions and peppers in containers this year. Where would these do best?

A: That adds up. Most herbs and veggies do best in full sun, but in pots and those hanging tomato bags, hot afternoon sites dry out very fast.

Hanging bags and hanging baskets are particular challenges because those hot summer breezes can dry soil on all sides as well as underneath. The smaller the container, the faster it dries out. If you don’t water them daily or even twice daily in really hot spells, the plants really stress.

Your morning-sun front porch is more forgiving when it comes to water loss, but the less sun will be a tradeoff in yield and probably taste.

Leafy herbs, lettuce and probably the onions should do fine in the front. Fruiters like tomatoes and peppers will do best in the back – but only if you can stay ahead of the watering.

A few strategies…

1.) Grow in pots instead of baskets.

2.) Use big pots. More soil insulates the roots better and takes longer to dry out.

3.) Work water-absorbing polymer crystals into the potting soil before planting. These are pellets that soak up water and release it slowly as the soil dries. SoilMoist and TerraSorb are two brands you might find in stores.

4.) Check soil moisture daily with a high-tech water gauge (your index finger). If the soil isn’t damp, soak it until water comes out the bottom drainage holes.

5.) Consider rigging up drip-irrigation lines. You can attach emitters to a line in each pot and even get an automatic timer that turns on the water once or twice a day as you determine it’s needed.

6.) Group your pots together to make a potted garden on the deck. That also cuts down evaporation loss. Single pots out in the open will dry quicker.

Don’t overlook fertilizing regularly. With all the watering, nutrients will leach out the bottom along with the drainage. Use a diluted balanced fertilizer once or twice a week. It’s difficult to over-fertilize outdoor potted plants. Better to add weak amounts often rather than one big shot once a month. Nutrients affect your veggies’ flavor as well as the sunlight.

Although pot gardening takes a lot more watering than in-ground plants, the results can be just as good. And there are advantages, like less animal trouble and less weeding.

Bleeding Heart Perennial

Gardening Q & A

Answers to your gardening questions and other tips by George Weigel.