Studying and Planning

January is THE time for planning, so it’s a good time to browse this blog and the articles on our website for ideas for spring planting, especially the articles about about plants – the perennials, trees and shrubs, native plants, and so on.  Email us with your questions – or put them in a comment to this article -  and we’ll try to answer them. Attend some of our free lectures or inexpensive workshops–the more you know, the easier and more rewarding it is to garden. If you haven’t ever done so, make a to-scale sketch of your yard, placing the trees and shrubs. Think about where you have room for more. When the bulbs and perennials emerge in spring, add them to the sketch. It’s a great planning tool for deciding what else to plant this spring.

Winter Supplies

• If you don’t have a snow shovel in good working order get one now before you need it desperately.   Same goes for a supply of snow- and ice-melting products; we’ve already had some icy steps and there will be lots more.  The University of Maryland reminds us to keep all ice melting materials away from landscape plants, and to NOT use granular garden fertilizers to melt ice – they’re very corrosive to concrete and metal, and contribute to waterway pollution.
• In case of loss of power or just because fires in the fireplace are such a pleasure, pick up some kiln-dried firewood, too.

Maintenance Jobs for Winter

• Larry Hurley writes that in the winter he likes to “do all the things that seem like a pain when it’s hot and buggy out. Cut back that bamboo that you always meant to clean up, dig out invasive ground covers like English ivy. Make sure your gutters are clean. It will reduce the risk of ice dams if we have heavy snow this winter, and during rainstorms the water will flow down the down spout instead of along your foundation, reducing the risk of basement flooding.  Clean mowers and other outdoor power tools if you know what you’re doing. Sharpen shovels and other bladed hand tools, and apply a light coat of oil to reduce rust.”

 Trees and Shrubs

• Winter is the best time to prune deciduous (leaf-dropping) trees and shrubs because you can easily see where branches rub against each other, spot dead or broken branches, and see how you might prune to improve form. Remove suckers and water sprouts, too.  But remember that you will be removing flower buds on spring bloomers, so be conservative if that is an issue. Watch for our free “how to prune” talks later this winter.
• Protect evergreens that are prone to winter burn – like boxwoods and hollies – with an anti-dessicant (Wilt-Stop) or protectant (Freeze-Pruf) now.
• If you have yews or camellias, look for white cottony masses on the undersides of needles/leaves. These are scale insects and they should be sprayed with horticultural oil later in the season when the youngsters (aptly named crawlers) emerge.
• Got deer?  Now’s the season when they home in on our more expensive plants, like trees and shrubs.  So apply Liquid Fence or Plantskydd (our favorites) monthly.
• If/when it snows, try to prevent snow and ice from building up on gutters and eaves above shrubs. Gently sweep snow loads off of shrubs to prevent breakage.
• Remove and destroy bagworm bags from affected trees- principally on evergreens. The bags contain hundreds of eggs that will hatch out and feed next spring.
• This is a good time to inspect winter creeper and Japanese euonymus foliage for scale problems.  Prune out damaged leaves and control the scale insects by spraying the healthy leaves with dormant oil.  Be sure that temperatures are expected to remain above freezing for a 24 hour period after spraying.

Bulbs

• Plant left-over bulbs in the garden as long as the soil can be worked.

Edibles

• Plan for spring seeding now.  Here’s how to check your last year’s seeds to see if they’re still viable:  Place 10 seeds between moistened paper towels, roll up the towel and place it in a plastic bag. Put the bag on top of the refrigerator or other warm location and check after 5-7 days to see what percentage has germinated. Discard seed lots with less than 75% germination.
• Get your seed-starting gear in order.  Lights working?
• By mid-January, seeds will be in stock.  Buy them early, before the supplies dwindle.
• Fall-bearing raspberries can be cut down to the ground and the spent fruiting canes of June bearers can also be removed now.

Lawn

• Avoid excessive walking on your grass when it is frozen to avoid damaging the crowns of your grass plants.

Houseplants

• Keep an eye out for pests on your houseplants – like spider mites, mealybugs and scale insects.  If you act quickly, most pests can be eradicated with simple methods, like a spray of water, spraying with insecticidal soap, or swabbing the critters (especially mealybugs) with a Q-tip dipped in rubbing alcohol.
• Be careful not to overwater.  And remember – don’t fertilize houseplants this time of year.  It will tell you when it’s ready for action.

Wildlife

• Keep bird feeders clean and replenished throughout the winter months.  If you started feeding them in early winter, they’re depending on you.
• Likewise, remember that wildlife needs a water source through the winter. Refill your weather-resistant birdbaths regularly.
• If you have a pond, keep a portion of the surface clear of ice at all times. If the water freezes over completely your fish may die. When ice forms, there is a strong chance that gasses from organic debris at the bottom of the pond will build up in the trapped water and harm the fish. There are a number of electric pond de-icers available that will provide a constant unfrozen area in the water. There are also some small bird bath warmers that do the same thing.
• Ceramic and plastic birdbaths are especially vulnerable to cracking in cold weather and should be stored indoors.  Metal ones should be unaffected by freezing so keep them outside.
• If you garden near deer, keep up the deer repellants through this, the most vulnerable time for evergreens.  Use monthly, rotating two or more different products.

Photo credits: Snow shovel, fireplace,  birds at feeder.

Mums look awesome with stone. Who'd have thought?

by Susan Harris
I may get called an “experienced gardener” but I’m no plant snob and I actually prefer the more common plants.  They’re usually cheaper and easier, and I like trying to use them in unique ways.  Plus, if they’re annuals, like most mums, I get to try different ones every year.  And as the season winds down, mums are just soooo colorful.  Check out these examples of mums used in fun ways.

I asked Behnkes’ Sissy McKenzie about mums and she advises buying them NOW for the best assortment of colors, sizes and bloom types.  Colors available include red, yellow, lavender/pink, bronze, and more.

Mums with Japanese maples at Brookside Gardens

Sissy’s Design Tips for Mums
Mums are the divas of the fall garden!  They can be mass planted to make a colorful edge to any garden.  They can be used to accent a flower bed or to set on a door step for a brilliant show of color.   They also make wonderful companions to your fall decorations, adding color around pumpkins, corn stalks, gourds – they add great texture and color to any decorations.

Mums also make excellent container plants, decorating your deck, front porch or pool area.

Sissy’s Mum-Growing Tips
Mums are a full sun plant, so remember at least 6 hours of sunlight is important to the health of your plant.  Mums need to be regularly watered and feed once a month to keep their leaf color.

Potted mums outside Behnkes in Beltsville

Seen in a Japanese garden.

Mums Up-Close

Photographers love using their macro lenses on mums!

Photo credits:  Mums with stone.  Massed with bamboo screen.  In Japan.  In collage:  upper left,  upper right, both lower photos.  Brookside and Behnkes photos by Susan Harris.

by Kathy Jentz, editor/publisher of Washington Gardener Magazine

This colorful fall container includes salvia, heuchera, calibrachoa, acorus, osteospermum, and ceratostigma from Proven Winners’ Fall Magic® collection in a gorgeous glazed planter.

This is the time of year when leaves are falling, frost is on your windows, and your planting beds are looking a bit bare.  But when that cold snap hits and kills off your summer annuals, you don’t have to abandon your containers and give into the winter blahs.  Instead, use this transitional period to put in some hardy plants now that will get you through until the spring thaw.

There are two schools of thought on containers. Some advocate the one-plant-for-one-pot look. You then mass the pots in groupings. The other technique is to cram-and-jam at least three kinds of plant in one large pot (one tall, one bushy, one trailing). Both styles have their use and appeal depending on the effect you want. In the dead of winter, though, I prefer the one plant/one pot approach as it is just easier to substitute out any failures and will look less “skimpy.”

Choose containers that are gorgeous, such as glazed pottery. In fall/winter, plants are less full, so the containers you use are more important than in other seasons. For a designer look, group together pots that are of the same materials or of coordinating colors.

Use props and fillers to give the illusion of fullness in your plantings. Try pots filled with dried seed heads, squash, and gourds. Stack hay bales, wooden crates, and nice rocks or fossils. Display antique wood and iron pieces, hypertufa spheres, and stone figures. Add white lights or holiday décor, as seasonally appropriate.

Keep your winter containers only in high traffic areas (i.e. near entrances). Do this not only because they are the only places people will see them, but also because in winter’s cold you won’t want to be outside more than a few minutes to maintain them.

Stuff the bottom of containers with a filler, such as styrofoam chips or lava rocks, to ensure good drainage. This is even more crucial in winter than the rest of the year. The freezing rains we get in the DC area in late winter can be brutal to any planting.

Containers need extra fertilizer, but don’t overdo it in winter. Cut back on watering as well, especially if rains are fairly frequent – only water if the container is under a roof or ledge.

Top off container plantings with an insulator — mulch, pea gravel, peat moss, bark mulch, et cetera. They provide protection from the cold and keep the soil from drying out. They can also disguise plastic planting pots if you just pop them inside more decorative containers.

Consider planting a layer of bulbs now as you pot up your containers. They will pop up next spring and are a low-cost, easy step.

A simple winter container is a small boxwood or evergreen in stone (or faux) container surrounded by pansies. It’s easy to under-plant the pansies with small spring-flowering bulbs such as muscari (grape hyacinths).

When choosing plants, combine textures and colors. Consider a display of three, five, or seven different kinds of boxwoods. Try newer boxwood varieties like ‘Green Pillow’ next to ‘Elegantissimo’.

Try a sculptural display of twisted willow or other interesting branches. Just twist up chicken wire into a cage in the bottom of your pot to support the sticks. Twist ivy throughout them to create an interesting effect.

Another striking winter container idea is a golden holly in topiary standard form, surrounded at its base by pine cones spray-painted gold.

Lastly, remember that containers are ideal because they can be moved! If a hard freeze comes in and you have some “borderline” or less hardy items planted, you can move them indoors or into a sheltered area for a few days.

Fall/Winter Container Plant List

Tall: Grasses, Sedges, Evergreens, Topiary/standards, Small trees, Twisted willow, Harry Lauder’s walking stick

Bushy/Full/Filler: Flowering kales and cabbages, Plumbago, Nandina domestica ‘Heavenly Bamboo’,  Boxwood, Evergreens/conifers, Barberry, Cypress, Sedums, Mums, Asters, Heuchera, Dianthus, Primroses, Violets/pansies, Bergenia, Salvia, Ajuga, Pachysandra, Cotoneaster conspicuous ‘decorus’, Lavender, Arundinaria pygmaea/mini-bamboo, Skimmia rubella, Heather, Convolvulus cneorum/Bush Morning Glory/Silverbush, Holly/golden holly

Trailing:  Periwinkle/vinca, Ivy, Creeping jenny, Bacopa, Sweet alyssum

Washington Gardener Magazine covers gardening in the Mid-Atlantic region only, and it’s written by regional garden writers. Photos taken by Kathy Jentz a few years ago at the Eastern Performance Trials at River Farm in Alexandria, VA.

Alternative Lifestyles: Planting with Nature in Mind

By: John Peter Thompson, Chairman, Behnke Nurseries; for more information on invasive species and sustainable, conservation landscaping go to his web log, INVASIVE NOTES 

For many gardeners, the term “invasive plant” spreads terror and discord, creating waves of anxiety and resentment. Currently, invasive plants are defined to be non-native, exotic aliens which reproduce furiously, replacing native plant species and complex self-sustaining ecosystems with, in some cases, biological deserts or monocultures.

The same qualities that make these plants invasive–they reproduce freely, grow voraciously and are virtually indestructible–ensure that they will become champion garden-trade species.

One way to think of invasive species is to think of all the weeds we do not want in our own gardens. The worst ones are those that creep in from our neighbors’ untended yards. Think “running bamboo,” and understand the feelings of those who are tasked with protecting natural areas. They are gardening with a “native-only” concept, and we are gardening with the “anything goes” model. This situation makes for uneasy neighbors, and opportunities for stress and discord.

Not all invasive species were introduced by gardeners or garden centers. Many simply hitched a ride on the bottom of a boot or in the cargo hold of a transport ship; even in the crates of packing materials we use to ship our consumer goods. But some, like kudzu, were originally introduced by the horticulture industry (1876), even though it took federal help to establish kudzu in our southern landscapes. Callery pear hybrids abound in the mid-Atlantic region as a highly recognizable invasive species, and are still recommended by local government agencies (Prince George’s County tree) as a street tree choice, even though the tree is almost always a bad long term landscaping solution.

When choosing plants for your garden, you should know the needs of each plant you select. Does it need light or shade; what are the optimum soil types; how wet or dry is best for your species; and what are the potential impacts on your immediate and regional ecosystem? Using native alternatives to invasive plants reduces the environmental impact and allows you to concentrate on the right plant in the right place.

What are some of the bad actors and what can we replace them with? Lythrum, or purple loosestrife, is a spike-flowered invasive perennial which can be replaced in the garden by Liatris spicata (also known as gay feather or blazing star), an excellent native alternative. Liatris is easily grown in average, medium-wet, well-drained soils in full sun. Once established, liatris tolerates poor soils, drought, summer heat and humidity, but is intolerant of wet soils in winter. The two foot tall clump-forming perennial has long spikes of rounded, fluffy, deep purple flower heads, appearing atop rigid, erect, leafy flower stalks.

If you are seeking a long summer bloomer to match the floral display of lythrum, try hybrid hibiscus such as ‘Lord Baltimore.’ Huge flowers, reliably perennial and fast growing, this plant will fill the summer and fall garden with knock-your-socks-off beauty until frost. Although they prefer wet soils, I have seen them tolerate some fairly dry conditions. And since they grow so fast, they can out-compete many pests, such as another invasive species, the Japanese beetle.

Another bad actor is English ivy. Drive through Rock Creek Park in Washington, DC (or the grounds of my house, and probably your house, too), and the evergreen vine which is pulling off branches of the shade trees is Hedera helix. It is tough to beat English ivy for an all-purpose, practical, indestructible, inexpensive and easy-to-grow ground cover. You do not need to weed it, feed it, water it, mow it, trim it or think about it until it pulls down a major shade tree or your gutter system to your house.

A terrific alternative is Pachysandra procumbens, or Allegheny spurge. This plant is native to the eastern United States and is not to be confused with the evergreen pachysandra you are used to seeing everywhere; that one is not native, and shows up on some “good plants gone bad” lists. Allegheny spurge is best in rich, moist soils and grows to around 12 inches high. It will grow in shade to part shade. In mild winters it may be partially evergreen.

Another great native alternative, Polystichum acrostichoides, Christmas fern, grows in the natural areas of the mid-Atlantic. An absolutely wonderful, shade loving, no-maintenance plant, it has the additional feature of being evergreen. It thrives under trees, and can often be seen in quite dry conditions. Planted en masse, this 24 inch tall species is a workhorse of the shade garden.

An added bonus is that the Eastern white-tailed deer, with its voracious appetite and very bad manners, will eat almost anything else before the Christmas fern. In fact I have a rule which states that deer eat five hundred dollar exotics first, followed by many rare and endangered natives second, and then pretty much everything else. The Christmas fern manages to find a way off of the dinner menu and thus is a perfect choice for a native, natural, and non-controversial landscape solution.

There are other Maryland natives which are easily found in nurseries and can be used as groundcovers, including Tiarella cordifolia, or foam flower, with white flowers and a preference for moist shade locations. Another is Phlox stolonifera, or woodland phlox, in pinks, blues, and whites, which rise to 8 inches tall when in bloom in April.

As a rule, vines are troublesome. Their rambling nature predisposes them to invasiveness. A list of vines which have gotten loose in natural areas is a list of the naturalists’ most abhorred. Consider porcelain berry, Japanese and Chinese wisterias, Asiatic bittersweet, Japanese or Hall’s honeysuckle: these plants terrorize natural areas and native ecosystems. But all is not lost, for there are many well behaved native alternatives such as Wisteria frutescens, or American wisteria, which produces a gentler, not-so-over-the-top inflorescence and a willingness to live with its neighbors, gently draping itself across lateral tree branches.

If you don’t mind dealing with its aggressive tendencies, then the native trumpet vine, Campsis radicans, is for you. Although aggressive to the point of being rampant, it provides brilliantly colored flowers which serve to attract hummingbirds. The orange, yellow or red flowers are true show stoppers.

Tiarella cordifolia

Another great native alternative, Polystichum acrostichoides, Christmas fern, grows in the natural areas of the mid-Atlantic. An absolutely wonderful, shade loving, no-maintenance plant, it has the additional feature of being evergreen. It thrives under trees, and can often be seen in quite dry conditions. Planted en masse, this 24 inch tall species is a workhorse of the shade garden.

An added bonus is that the Eastern white-tailed deer, with its voracious appetite and very bad manners, will eat almost anything else before the Christmas fern. In fact I have a rule which states that deer eat five hundred dollar exotics first, followed by many rare and endangered natives second, and then pretty much everything else. The Christmas fern manages to find a way off of the dinner menu and thus is a perfect choice for a native, natural, and non-controversial landscape solution.

There are other Maryland natives which are easily found in nurseries and can be used as groundcovers, including Tiarella cordifolia, or foam flower, with white flowers and a preference for moist shade locations. Another is Phlox stolonifera, or woodland phlox, in pinks, blues, and whites, which rise to 8 inches tall when in bloom in April.

As a rule, vines are troublesome. Their rambling nature predisposes them to invasiveness. A list of vines which have gotten loose in natural areas is a list of the naturalists’ most abhorred. Consider porcelain berry, Japanese and Chinese wisterias, Asiatic bittersweet, Japanese or Hall’s honeysuckle: these plants terrorize natural areas and native ecosystems. But all is not lost, for there are many well behaved native alternatives such as Wisteria frutescens, or American wisteria, which produces a gentler, not-so-over-the-top inflorescence and a willingness to live with its neighbors, gently draping itself across lateral tree branches.

If you don’t mind dealing with its aggressive tendencies, then the native trumpet vine, Campsis radicans, is for you. Although aggressive to the point of being rampant, it provides brilliantly colored flowers which serve to attract hummingbirds. The orange, yellow or red flowers are true show stoppers.