Diggin' It
Conflicting news about weeds and climate change
The bad news is that global warming is increasing the aggressiveness of some weeds, says the Weed Science Society of America. The good news is that some scientists in Australia don't necessarily agree.
Once summer's heat and humidity soar, I don't want to think about weeds. And I imagine I'm not alone in feeling that way. Unfortunately, the weeds are there and have to be dealt with.
If the Weed Science folks are right, that's going to get more difficult:
They point out that the rising amount of carbon dioxide in the atmosphere caused by increased temperatures is expected to help vegetables and grains grow more quickly and produce greater yields.
Unfortunately, that impact could be even more pronounced in weeds than in good crops.
So, how much faster will the weeds grow with warmer temps and higher carbon dioxide levels? About four times more, several studies by the USDA's Agricultural Research Service showed.
Interestingly, the Monitor has been reporting this since 1995.
But wait a minute, say researchers at the School of Plant Science at the University of Tasmania. Their seven-year study suggests that for many weeds, the increase in growth caused by more CO2 is offset by the rising temperatures.
"When you add warming to an experiment as well, the warming actually knocks the weeds out very strongly," said Mark Hovenden.
He specifically mentions that bane of suburban lawns – dandelions.
Dr. Hovenden also adds a caveat to the belief that carbon dioxide will increase good plant growth across the board. That will be dependent on ample summer rainfall, he says.
A third voice – Arthur Weis, a professor of ecology and evolutionary biology at the University of California at Irvine – conducted studies that predict that weeds will evolve to cope with climate change.
So here you have a group of scientists saying climate change will probably make it harder and more expensive to control weeds, which will dramatically increase the pollen in the air.
And a different group says their experience shows that climate change slows weed invasion.
And, lest that get you feeling hopeful – another study shows how quickly weeds can adapt to global warming.
If you'll excuse me, I'm going to slip on my heavy-duty garden gloves and pull some weeds while I think about all this. That's when I do my best thinking.
Note added on 6/29: You may want to look at Tom Christopher's article, "Can Weeds Help Solve the Climate Crisis," in The New York Times Magazine.
CITY IN BLOOM: From June 26 until Labor Day, Chicago's Magnificent Mile is filled with flower gardens. (Courtesy of Greater North Michigan Avenue Association)
Flowers and fashion in Chicago
If you’re in Chicago between June 26 and Sept. 1, do plan a stroll along the Windy City’s Magnificent Mile.
Not only will you gaze at great flower gardens, but the annual ComEd Gardens of the Magnificient Mile – dozens of small gardens funded by the high-end hotels, restaurants, and retailers along north Michigan Avenue – have some zany green inhabitants.
For the second year, students from the International Academy of Design and Technology and the Illinois Institute of Art - Chicago have been given dress forms and asked to adorn them creatively in recycled materials.
These could be anything from old chicken wire to a hat like one Queen Elizabeth might have worn in the mid-1950s. Think of it as a green take on the traditional department-store mannequin.
These creations are then placed in individual gardens. And they'll be auctioned off, with the funds going to the Magnificent Mile Charitable Foundation.
I was intrigued as I read the list of gardens and what plants the plots will contain. Experienced gardeners will get a chuckle from some of the plant descriptions – hibiscus trees, cherry wavy petunias, etc. – which were obviously compiled by nongardeners (and probably over the phone since many have phonetic spellings). But that's OK – lots of us don't speak Latin fluently.
It sounds like typecasting, but the Apple Computer store will host a Zen garden, which “gives a tropical feel of calm serenity.”
U.S. Equities Realty, at 840 N. Michican Ave., calls its garden Tropical Typhoon. Expect “a fiery vortex of Iresine [that] leads into a tropical paradise of reds, oranges, & purples parted by an electrifying lime Coleus.”
(Whoever wrote that description could have a great future in the gardening industry. If I read it on the cover of a gardening magazine. I wouldn't be able to resist buying a copy.)
The Westin Chicago River North calls its garden Simply Chic, noting that "the garden's modern clean look is created by using a combination of three plants. The backdrop is a Cordyline terminalis 'Kiwi' that has a variegated leaves of green, yellow, and chartruese pink. A blue 'Artichoke' Agave serves as the accent plant in the bed of 'Purple Heart' Tradescantia."
It does sound simple and appealing.
If you plan to visit Chicago this summer, you can download a map of the gardens.
And you'll definitely want the list of the student's sketches and where their creations will be located. And should you fall in love with any, they'll all be sold on eBay this summer.
Many cities plan summer promotions – to attract visitors, to keep tourists in shopping areas longer, and as just plain fun for residents. I like Chicago's gardens – and their recycled fashion – better than the painted cows, fish, and other critters that have been populating cities the past few summers.
It’s always good to add some greenery to the ordinary shopping scenery.
More great garden blogs
Everyone’s blogging these days, and that includes gardeners. So each Thursday we poke around the Web to find a few of the most interesting gardeners and gardens.
I enjoy reading about others’ gardening experiences. Often, it's like a friendly conversation across the back fence. But I’ve also found that frequently I pick up tips and ideas that help me in my own garden.
That’s what happened when I dropped in on The Cottage Smallholder. It’s maintained by a family living in a 17th-century cottage on the border of Cambridgeshire and Suffolk in England.
Working toward self-sufficiency, they have a menagerie that includes four dogs, one Maran hen, four bantams, two guinea hens, a pair of bee hives, toads, frogs, and more.
Just before my visit to The Cottage Smallholder, Diggin' It had been discussing slugs and snails. So I was excited to read a remedy I’d never tried before:
She says that traps filled with "stale" milk work well. I hope so, because I'm going to give it a try.
Food is a regular topic at this site, and the recipes sound delicious, but the ingredients are in British measurements, of course.
For Americans, the recipes at Farmgirl Fare will be in the more familiar format, but just as tempting. Currently she’s discussing ways to use Swiss chard (including an appealing-looking Swiss Chard Tuna Salad).
I’ve already copied the directions for Summer in a Bowl so I can have it ready when my home-grown tomatoes begin ripening.
The writer lives on a remote 240-acre farm in central Missouri and posts lots of cute photos of baby farm animals – donkeys, lambs, goats.
The same person maintains InMyKitchenGarden, which is all about food – a handy site to bookmark with all the summer produce on its way.
In Australia, winter is one the minds of gardeners such as the one who writes about Scarecrow’s Garden, where the current harvest includes broccoli, peppers, lots of herbs, and four to six fresh eggs a day.
A woman and her husband (with children grown and on their own) live on a half-acre in the “dry Mid North of South Australia.” She details a life that’s fascinating to someone like me, who gardens halfway around the globe.
A current interest at Scarecrow’s Garden is Freedom Gardens , an expansion on the old Victory Garden idea from the World War II era. Although it has a worldwide reach, it’s based in California.
Which all goes to show how, thanks to the Web, we're all interconnected these days.
Top gardening searches last week
Yahoo! just released a list of the top 20 fruits and vegetables that were searched for on its site last week:
Growing Tomatoes
Growing Cucumbers
Growing Strawberries
Growing Herbs
Growing Grapes
Growing Cilantro
Growing Rhubarb
Growing Potatoes
Growing Tomatoes Upside Down
Growing Garlic
Growing Asparagus
Growing Pumpkins
Growing Basil
Growing Broccoli
Growing Blueberries
Growing Green Beans
Growing Onions
Growing Watermelons
Growing Sweet Potatoes
Growing Peppers
That tomatoes and cukes top the list doesn't surprise me, but having strawberries, rhubarb, grapes, and sweet potatoes on it does – if these inquiries are coming from inexperienced gardeners.
I don't want to discourage anyone, but folks, strawberries, grapes, and asparagus take time and effort. Not that everyone can't do it (I'm a rah-rah gardener; I believe anyone can succeed) , but I've seen so many gardeners who were filled with enthusiasm early in the season and then gave up because of heat, humidity, weeds, and bugs.
And I wonder what prompted all the searches for growing tomatoes upside down. I'll concede that the method is different -- no doubt it prompts many neighborhood discussions – but I've never quite figured why I'd want to do it.
Yahoo also reports that queries for the terms “vegetable gardening,” “organic gardening,” and “container gardening" have more than doubled since last year, which is good news for the gardening world (including those of us who write about it).
Maybe those searchers will get so excited about growing tomatoes upside down in buckets that they'll enjoy more conventional crops, too. Or maybe they'll join those folks who strive for the biggest tomato or a record-breaking pumpkin in the world.
There's room in gardening for all of us.
Slugs, and snails, and …
Well, no, that’s not exactly how the nursery rhyme goes. And I doubt that puppy dog tails are the cause of too many holes in hosta leaves . But “slugs and snails” – now that’s a slimy refrain repeated with dismay by gardeners across the land.
What to do? There are all sorts of home remedies – none of which work all the time for all situations, but at least one is usually effective for your garden. There’s also a widely available organic commercial slug killer on the market.
Here are the remedies I’ve used at different times and in different parts of the country:
Forget putting out saucers of beer for the slugs to fall into and drown. Generally, yeast is more effective. Mix one-fourth teaspoon yeast and 1 teaspoon sugar in 1 cup of water and fill shallow saucers. About 9 p.m., place them in areas where damage has occurred. For best results, remove them the next morning.
There are several drawbacks: If it rains, the liquid is diluted. (You can find covered traps at garden centers.) It can also attract dogs and cats (although it won’t harm them). And it works for only a few days, then the creatures ignore the mixture.
Like many gardeners, I’ve tried the technique of placing some sort of harsh material around desirable plants as a barrier, with the idea that soft-bodied snails and slugs will be harmed by slithering over them. Eggshells, sharp gravel, cocoa shells (sold as mulch), sandpaper, and wood ashes are all worth a try. But keep ashes – which have a liming effect – away from plants that need acid soil.
One of the problems of trying to keep slugs away with a barrier is that often they are already hiding near the plant – beneath those conveniently wide hosta leaves, for instance.
On sidewalks, driveways, and paths, a 4-inch-wide strip of lime will dissolve slugs and snails. But again, shouldn’t be used near plants that like acid soil.
Sprinkling salt on slugs will dissolve them, but salt can be harmful for plants. (You may want to try rock salt beneath stones or pavers, where slugs tend to hide.)
Installing copper strip barriers can be effective, but is expensive. (If you want to go this route, ask at a hobby shop about copper strips; they’re less expensive than the ones sold for gardening.) The drawback: the edges of strips are sharp and can easily cut.
Of course, you can pull the slugs and snails off plants by hand and/or step on them on the ground. But I can’t bring myself to do it; I shudder just thinking about it.
Ducks and some birds also love to make a meal of slugs, so you’ll want to encourage their presence in your yard.
I’ve never tried Sluggo , an organic slug remedy made from iron phosphate. It’s not toxic to animals and kids, but does take up to a week to kill mollusks.
With all the time I’ve spent over the years fighting slugs and snails, what I haven’t figured out, though, is how they know exactly which hosta you’ve paid the most money for, so they can target it as the piece de resistance of their summer awards banquet.
An open invitation to hummingbirds
Just about everything about hummingbirds is amazing – from their tiny size to their speed to their feistiness.
They're native to the Western Hemisphere and live from Chile to Alaska. Anyone who's ever had them visit wants them to return. They're more entertaining than a TV reality show.
There are two methods of attracting hummers to your garden.
First: Know which months hummingbirds are in your part of the country and try to have flowers they like in bloom all that time, if you can.
Hummers feed on the nectar in flowers – red and orange ones, particularly – that are tubular or trumpet-shaped.
There are so many plants they like – not just annual flowers, but shrubs, vines, and perennials, too – that it’s fairly easy to offer them something throughout the time they're in residence.
You'll find many lists of hummingbird-attracting plants on the Web and in books, but which plants are right for your garden depends on where you live.
Among my favorites are Agastache, azalea, cardinal flower, dahlia, Heuchera, hollyhock, rose of Sharon, and trumpet honeysuckle (Lonicera sempervirens), a delightful vine. (Avoid Japanese honeysuckle, though, because it takes over.)
Don't use pesticides if you want hummingbirds as visitors. They're attracted by small insects (which provide protein for their diet).
You may also want to supplement the plants with a hummingbird feeder or two. They’re perfect for those who live in apartments and don’t have a garden.
The big problem with feeders is that you have to clean them two or three times a week, depending on the heat and humidity where you live.
To make nectar for the feeder, mix ¼ cup of sugar in 1 cup of water and pour into a clean feeder. (Or to make larger or smaller amounts, just stick to a 1 to 4 ratio.) Don't use red food coloring.
If possible, consider having several small feeders – out of sight of one another – rather than one large one, because hummers are very territorial. And because they eat almost constantly.
Gardeners often champion native plants. Here's a native bird that's fun to invite to our gardens, too.
Make herb vinegar
Sometimes, anticipation is the best part of gardening. Right now I’m dreaming of herb vinegar. And I’m making a list of the supplies I’ll need to make my own. I have my herbs growing, of course, so I'll need to get some quart-size canning jars and different types of vinegar.
All during the year, I collect attractive bottles to pour the finished vinegar into, because often I end up giving them to friends. They make great thank-you gifts.
If you’ve never made herb vinegar before, you’ll find it couldn’t be simpler.
While there are many methods, I learned from Jim Long of Long Creek Herbs in Missouri. He has a great little booklet, “Making Herb Vinegars,” which suggests some really good combinations (how about Dark Opal Verbena Vinegar?) and includes 55 tasty recipes, too.
What herbs make the best vinegar? They’re all fine; it just depends on which flavors you like best. Basil, bay, fennel, oregano, rosemary, lavender, tarragon, dill, chives, lemon balm, marjoram, sage, cardamom seeds, even mint – all make excellent vinegars that enliven salads and other dishes.
So you start with the herbs you like and use most. Then you choose a vinegar – or several. In my experience, white distilled vinegar doesn’t have the smooth taste I’m looking for. But I have tried almost every other kind.
The most versatile – and least expensive – is cider vinegar. I like rice vinegar, too. Buy a top-quality brand of whichever vinegar you decide on.
The day before you plan to make the vinegar, wash your Mason jars (or other wide-topped glass containers with lids) and let dry overnight.
The next morning, pick your herbs before the sun gets on the leaves, rinse them lightly with water, and spin them in your salad spinner to remove the excess water from the leaves. (You can also lightly dry them with paper towels.)
Then loosely add the combinations of herbs you’ve chosen till the jars are about three-fourths filled and pour in vinegar to within an inch of the top of the jar. Because you want to avoid metal around vinegarmaking, cover the opening with plastic wrap before screwing on the lid. Then place the jars in a dark spot for about two weeks.
Shake the jars every other day, and as you do, you’ll get a feeling for how strong the vinegar has become.
When it’s ready, pour the vinegar through a strainer into a clean bottle, adding a couple of sprigs of fresh herb, if you like. Cork and store away from strong light. Don’t forget to label it! It should keep at least a year.
And those you give it to – if your family will let any out of the house – will think you’ve done something really special. Only you know how easy it really was.
More garden visits
Each Thursday, Diggin’ It pokes around the corners of the Web to see what other gardeners are doing and writing about. This week we visit Canada, Poland, Iowa, and California.
In Naramata, British Columbia, the Kitchen Garden Gourmet specializes in heirloom vegetables – Moonglow, Striped Carava, and Silver Fir Tree tomatoes, Rampicante zucchini, Guatemalan Blue Banana squash, and Buran peppers, among many, many others. The list and descriptions of the tomatoes alone will make you want to plant nothing but heirloom tomatoes this year so you can try one of two plants of each.
Ewa gardens in Poland (in what would be Zone 6 in the US) and you can read about it in English or Polish, if you prefer. It’s fun to see how the experiences of a gardener in central Europe mirrors the gardening life elsewhere – baby birds, visiting botanical gardens, moving loud-croaking frogs to a new home, getting rid of dandelions (complete with a recipe for dandelion syrup).
Even in summer, gardening isn’t all about the outdoors. (You’re sitting in front of your computer inside, right?) Mr. Subjunctive in Iowa City, Iowa, writes about his 377 – and counting –houseplants in Plants are the Strangest People. He also maintains Pick a Plant, a site to help people choose the right indoor plants for their homes. Because his daytime job is in a garden center, he often talks about what’s new on the market. I drool over the orchid photos.
Urban Sprouts will make you feel good. If you’re interested in gardening with kids – and introducing the next generation to growing plants – you’ll learn plenty, too.
Now we return home to our own gardens until next Thursday. If you aren’t quite ready to head back out into the yard, check out our earlier garden visits here and here .
Hydrangeas that bloom all summer
Earlier this week, we talked about the first repeat-blooming hydrangeas, Endless Summer. After a detour into repelling wildlife, we're back to look at a second group of hydrangeas that flower over and over, Forever and Ever.
Both groups are great for gardeners who live in cold climates, where hydrangeas rarely flower because their buds are killed by frost.
And they're the perfect answer for the perennial question, Why didn't my hydrangea bloom?
But they're great for any yard, because a shrub that flowers all summer definitely gives you more for your money than one that blooms once and that's it.
Except for weather issues, hydrangeas are easy to grow as long as you have a partially sunny spot with well-drained soil and can keep them watered.
There are now seven different Forever and Ever hydrangeas, which are listed for Zones 5-9. The one that will cause the most comments in your yard is Peppermint – 10-inch blooms with a streak of pink (or blue) down the center. Everyone who's seen mine had to examine the blooms close-up.
Want bright red hydrangea flowers? Forever and Ever delivers. I'll have to say I was very doubtful about the color of these blooms before I grew the plant myself. But it did deliver.
Here's a look at the others. (Another one will be introduced next year.)
In my experience, these repeat-bloomers – both Endless Summer and Forever and Ever – make fine plants for containers. I’ve grown both kinds in big pots for several years, moving them to an unheated garage during winter. (I live in Boston.)
I've gotta say I'm a big fan of both. I can't imagine gardening without them.
How do you deter critters in the garden?
We're looking for your tips on how to keep Bambi and Peter Rabbit from munching on your lettuce and turning your shrubs into dinner.
In response to the Q&A about some sort of animal munching on a hibiscus plant, Deborah King left a helpful comment that got me thinking.
She wrote: "In regards to the question about Hibiscus, I recently had a problem with our blueberry bush. Just as the blueberries were ripening, they disappeared. My husband observed a blue jay [did he say he saw a smile on the bird’s beak?] eating them.
"We mentioned this to our nursery and they suggested we spray the bush with a light coating of water and dry mustard. They said animals and birds don’t like the taste of mustard - and now I’m off to the store to buy some."
There are many commercial and homemade repellents to keep wildlife from destroying your plants. Just about all work some of the time, in some situations, and for some people.
But rarely is there one that works for everyone all the time. The best commercial repellents come close, but they're generally expensive and most have to be reapplied fairly often -- although that's getting better. And some aren't recommended for edible plants.
So I always ask other gardeners what has worked for them. With the blueberries Deborah mentions, I buy bird netting and drape it over the bushes before the berries start to change color.
A few – usually small – birds sometimes figure out how to get beneath the netting, but mostly their damage is slight. And the netting can be reused for several years.
Pepper spray has worked for me in the past: Chop up a hot pepper (you want at least 2 tablespoons), and put it in a blender with 1 tablespoon dish-washing liquid, 1-1/2 teaspoons garlic powder, and 1/4 cup water. Puree. Then pour into 1 gallon of water and spray on plants. (Make sure you get it on all parts of the plant, including the undersides of the leaves).
Another touted deterrent, bone meal, however, just seems to me to attract dogs, not keep them away.
I wish I'd known about homemade cat repellents in my last house.
I'm fortunate never to have had deer problems, but wonder if I'd really get desperate enough to spray rotten eggs.
Maybe so. The recent article in The New York Times about people reaching their limits of endurance and killing marauding critters in their gardens included plenty who'd reach the end of their proverbial ropes.
Keeping wildlife at bay is tough – and not the least because gardeners tend to love animals and want to live in harmony with them.
Previous
Become part of the Monitor community
36K on Facebook | 12K on Twitter | 2,250 on YouTube