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Fragrance in the Garden

As I matured as a gardener, I wanted more than just pretty flowers; therefore, fragrance became important. At the top of the fragrance list for me is the genus Syringa or lilac. Once I realized that fragrance could be an important part of the garden or landscape, I just had to have a lilac. We bought a white lilac (I like white flowers, especially in shady areas) and I was transported to heaven every spring when the white lilac bloomed. At this point, its site is too shady and I must remove it and make room for other plants. I will miss it and remember its heavenly fragrance. By the way, a wonderful small-leafed lilac, Syringa meyeri, with a different lovely fragrance, blooms a little later than Syringa vulgaris in part shade as well as in full sun, and has small, attractive leaves without the mildew.

Daphnes are notorious for dying for what appears to be no reason at all. Some years ago, I bought Daphne cneorum, the rose daphne, and before it was planted, it died! I had already tried Daphne x burkwoodii 'Carol Mackie' with no luck. At that point, I was very hesitant about trying another daphne. In Roslyn's Nursery catalog I saw the description of Daphne caucasica and thought that this was the one to try. So far it's proven to be very lively, grows to about 4 by 4 ft, is easily pruned to any size if needed, and has lovely white, fragrant flowers from spring to frost. It's definitely an asset in a part-shady site.


Winter Salt Damage to Trees

As I watched a large state highway truck salt the street during a recent snowstorm and then watched a little later in the evening a similar truck move all of that salted snow up onto our grass area where three Aristocrat pears grow, I wondered just how safe our trees are when subjected to this kind of treatment every year.

Over the past few years I've noticed much road salt damage to evergreens planted along busy and not-so-busy roads in the Bel Air area. So I started looking for some information on this subject and found an article in the American Nurseryman magazine dated March 15, 2003 that answered most of my questions. After reading the article and looking at a list of trees that tolerate this treatment, I felt a little relieved; at the same time I felt I also should warn homeowners about tree care and selection for planting along roads.

Apparently road salt damage mimics the symptoms of plant disease and insect damage. On top of this, trees stressed by salt damage are more susceptible to disease and insect problems as the stressed trees are not able to produce whatever chemicals are needed to control further damage.

I was surprised at a statement in the article that mentioned the spray from cars and trucks can carry salt to trees up to 150 feet from the highway. The salt covers the needle tips of conifers and within the year the affected needles die and fall off.

Deciduous trees are not as strongly affected as evergreens but salt can enter twigs and kill dormant buds and it appears that flower buds are especially vulnerable. Salt damage can also cause "witches' brooms" to grow.

Salt in the soil slows down the plant's ability to pick up nutrients from the soil. As you might think, young trees are more susceptible to this slowdown than mature trees.

What does salt damage look like? Look during early summer for browning of the edges of deciduous leaves and fallen needles on evergreens especially on the side toward the road.

What to do about salt damage?

  • Some homeowners are putting up barriers to protect their trees from salt damage on the leaves. This might protect the leaves but it doesn't protect the soil.
  • Flush well drained soils at the end of winter to flush away the salt residue.
  • Maintain plants in a healthy condition by providing adequate irrigation and mulch to reduce water loss.
  • Prune
  • Add fertilizer to correct nutrient deficiencies
  • Control damaging diseases and pest infestations.
  • Don't plant trees that are susceptible to salt injury along the road. Instead, plant trees that can tolerate salted roadsides.
  • You can save a lot of work and worry by NOT planting trees along a county or state road.

Here are the two lists: Trees to Consider and Trees to Avoid.

Trees to Consider Trees to Avoid
Acer campestre - hedge maple Acer rubrum - red maple
Acer pseudoplatanus - sycamore maple Acer saccharum - sugar maple
Caragana arborescens - Siberian pea tree Carpinus betulus - European hornbeam
Crataegus spp - hawthorn Celtis occidentalis - hackberry
Fraxinus spp. - ash Juglans nigra - black walnut
Ginkgo biloba - ginkgo Liriodendron tulipifera - tulip poplar
Gleditsia triacanthos inermis - thornless honeylocust Ostrya virginiana - American hophornbeam
Koelreuteria paniculata - goldenraintree Picea abies - Norway spruce
Maclura pomifera - Osage orange Picea glauca - white spruce
Pinus rigida - pitch pine Pinus strobus - white pine
Pinus thunbergii - Japanese black pine Pseudotsuga menziesii - Douglas fir
Quercus rubra - red oak Quercus bicolor - swamp white oak
Prunus sargentii - Sargent cherry Quercus palustris - pin oak
Pyrus calleryana - Callery pear Tilia americana 'Redmond' - basswood
Quercus robur - English oak Tilia cordata - littleleaf linden
Robinia pseudoacacia - black locust
Sophora japonica - scholar tree


A New Plant Palette - July 1999

I'm writing this on July 20th during the worst of 1999's terrible drought. Many of the plants I planted this year have not been able to keep turgid in this weather. From that standpoint it's been the worst drought yet, and while looking at the drooping and shriveling plants, I've decided to scratch them off my plant list.

What's being removed?
  • Thalictrum rochebrunianum 'Lavender Mist' - wilts,
  • Lamium maculatum 'Beedham's White' - needs more moisture than the plants get because it is on a slope,
  • Hydrangea 'Tokyo Delight' large leaves and needs moist soil,
  • Azaleas are dying back - needs moist soil,
  • Heuchera or alumroot needs moist soil,
  • Kalmia or mountain laurel - needs moist soil,
  • Astilbes - need moist soil,
What's doing well?
  • Dianthus 'Bath's Pink' - fragrant
  • Hardy Geraniums - keep on blooming
  • Chamaecyparis - needle evergreens
  • Deciduous shrubs such as lilacs, Fothergilla, and Spireas
  • Perennials such as Hemerocallis, Dianthus, Plumbago, Asiatic lilies, Hostas, Liriope and others.
  • many of evergreen hollies and Crepe Myrtles.

1999's drought also had an outdoor watering ban with it which was doubly hard on gardeners and their plants in the Bel Air area.


Caring for your Woodland

Some of my clients with wooded lots ask me for help in deciding what to do with their woods. When I meet with them, we walk along the woods boundary and discuss what I see in the woods and I tell them what's "good" and should be kept and what's "bad" and should be removed.

Our area of Maryland is divided into two sections, the lower one is called the "Coastal Plain" and runs along our waterways, and basically is the area from the Route 40/I-95 corridor east and south to the sandy shores along the water's edge. The upper area is called the Piedmont plateau and is composed of rolling hills and valleys. Each area has its own group of plants that grow and flourish in their respective areas. Some plants, though, grow in both areas.

In the Piedmont plateau you'll find tall trees including ash, maple, hickory, oak, pine, beech, cherry, and birch among many others. Some of the smaller-growing trees are dogwood, fringe tree, hornbeam, redbud, shadbush, and eastern red cedar. Shrubs include huckleberry, aronia, witch hazel, swamp rose, Pinxterbloom azalea, and many other plants.

I remember reading a long time ago that . . .

      "Nature never leaves a void"

Many plants that don't belong in our woods (sometimes called "invasive non-natives") grow there because birds or the wind deposit their seeds in the woods. You'll often find Norway maples (Acer platanoides), roses (Rosa species), honeysuckles (Lonicera species), burning bushes (Euonymus species), privets (Privet species), and other trees and shrubs growing.

After purchasing your wooded lot, I suggest not doing anything with the woods for a year. Each season during that first year, look closely to see what's blooming and growing. Take pictures of what the woods look like in the different seasons. If you find flowering plants take pictures of them when they are in flower.

If you don't want to grow flowering trees and shrubs in the woods then nothing much needs to be done. If poison ivy is growing near the edges you may want someone to come in and clear out the poison ivy. You can do it yourself but you need to wear protective clothing so you don't get infected. Don't burn poison ivy because the pathogens can become airborne and can be breathed in. That's a very bad thing.

If you do want to grow flowering trees and shrubs along the woods edge, then dig out the roots of unwanted plants. Oftentimes, there are too many tree saplings or small diameter trees growing as well and they will have to be removed so that there is room for other plants to grow. Poison ivy should also be removed. Remember that there are tree roots and many seeds in the ground ready to germinate with the new sunlight; therefore, after clearing the ground, you may see many seedlings for several years. Keep the ground heavily mulched to control seedling and tree regrowth.

Woods are an important part of our natural world. They produce food and nest sites for wildlife, including songbirds that we enjoy at our feeders in the winter, and they improve the quality of our rainwater because the roots absorb elements that may harm our streams and wells. If you have a large wooded area, don't try to clean it out all at once. Take your time and you may find that you like the sight and sound buffer that it provides. Eventually you may want to make at least a circuitous path through the woods so that you can enjoy it in the different seasons. Don't take on more than you have time or ability for.

In a recent Forestry bulletin of the Maryland Department of Natural Resources I found the following that mentions the need to not clean up the woods completely:


    ". . . Woodland owners are tempted to remove all standing dead trees to improve the appearance of their woodland. However, standing dead trees --- called snags -- and dead parts of live trees are "room and board" for many kinds of wildlife.

    . . . Woodpeckers, sapsuckers, flickers, chickadees, squirrels, raccoons, . . . all use tree cavities in forests. Bluebirds nest in snags in recently cut areas or in fence posts along farm fields. Insects in snags provide food for many woodland creatures."

Here's a link to information on Non-native Invasives. The Maryland Invasive Species Council (MISC) "encourages the prevention and management of invasive species in Maryland". Maryland Invasive Species Council.



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Indigofera kirilowii . . .

Picture

Six years ago I planted a false indigo I purchased from Plant Delights Nursery. Indigofera kirilowii is its botanical name. It is a small shrub growing to three feet by three feet and is easily pruned after it flowers. Its lovely pink flowers appear during June and July. My plant was blooming at the end of May. It has nice, bright-green, pea-like leaves as you can see from the picture. I have never really noticed it's fall color so I assume there is nothing special about it. In cold winters it could die back to the ground but will readily grow again from its roots. It flowers on new wood which is similar to the Buddleia.

I planted it in the only sunny spot in my back garden and it has done well with very little care. The catalog information notes that it needs moist, organic, and well drained soil. It is growing very well in clay soil and it doesn't get much care except a hair cut in early spring. It is watered when the other plants around it need water.

In my garden it is planted among yellow-leaved plants. That's Sedum 'Angelina' in front of it and a large-leaved Bergenia planted to its right. The plant comes from Korea and is hardy to USDA Zone 5. I have not seen any seedlings from it at all. I have read that since it readily puts out new shoots from its roots it can be used as a ground cover.

When searching the internet to see who carries it, just a few mail order nurseries do. This plant purchased from Plant Delights Nursery was from Christopher Lloyd's garden and grows to only 18 inches tall and that's the height of my plant as well.


Upright Plants for Narrow Places

As a landscape designer and a gardener who is a "plant nut", I am always looking for new and interesting trees and shrubs that enjoy living in our area and have characteristics that make them stand out from all of the new plants appearing in the garden catalogs. Since I am running out of gardening room in my own garden and since many of my clients tend to purchase small lots with large houses, the plants I need and that my clients need are oftentimes new upright cultivars of old favorites.

The past winter I picked "upright or narrow-growing plants" from a variety of nursery catalogs. Last year was the right year to do this search as there were plenty of plants to select.

Listed below are some of the plants I found in the catalogs as well as the upright plants I'm growing in my garden. Please note that the sizes shown are estimates only. The sizes are based on growth data from various sources. The notations show height first, then width. When I mention using a tree as a "street tree", there should be no utility wires above the tree.

Acer rubrum 'Scarsen' or Scarlet Sentinel red maple is listed on several street tree lists because of its compact size. Grows to 40x20ft. Plant in sun to part shade in average to wet soil. Red maples are one of my favorite large trees with their hazy, early-spring red flowers. Fall leaf color ranges from orange to red. It's a good size to use as a street tree or a shade tree.

Amelanchier canadensis 'Glenn Form' or Rainbow Pillar serviceberry grows to 20x8-15ft wide. Plant in sun to part shade in average garden soil. It has an upright form and is dense and multi branched. Like all serviceberries, it has white flowers in early spring and edible purple fruit which the birds eat. It's green leaves turn yellow, orange and finally red in the fall. Its late red fall color is spectacular. It's often suggested as a great hedge plant because of its upright form. If a large-size specimen of this tree is available, it would make an excellent corner-of-the-house tree. Some information on the internet suggests that this cultivar is not a good berry producer as other serviceberries.

Berberis thunbergii 'Helmond's Pillar' grows to 6x2ft. Plant in sun in well-drained soil. Leaves are burgundy and green out somewhat in the summer. Tiny yellow flowers produce small red fruits in the fall. Barberries are great container plants because of their hardiness ratings and will survive through most of our winters in containers. It makes a nice contrast plant wherever it is planted. I especially like it with red Pentas or Egyptian Star Flower and blue Dianthus foliage. Helmond Pillar has great red fall color.

Buxus sempervirens 'Graham Blandy' or Graham Blandy boxwood is a slender, columnar boxwood being the same width at the bottom and top. It grows to 12x1-2ft. Plant in sun to shade in regular garden soil including clay soil.

Buxus sempervirens 'Dee Runk' or Dee Runk boxwood grows to 12x2.5ft. Plant in sun to shade. Boxwoods are tolerant of clay soil. Of these two upright forms, I prefer Dee Runk because its form is more attractive being wider at the bottom than at the top. Both of these plants work well wherever you use them, whether in informal or formal gardens. It's always nice to see an exclamation point among rounded perennials or small, rounded shrubs! Dee Runk is harder to find but well worth the search.

Buxus sempervirens 'Argenteo Variegata' or 'Elegantissima' slowly grows to 8x4ft. This is an outstanding variegated boxwood with creamy-white leaf edges. Because of its variegated leaves, this boxwood looks better in part shade rather than in sun. It's beautiful for Christmas decorations and very distinctive. I like this planted in shady places where it can shine a little among all of the dark-green shade plants.

Carpinus betulus 'Fastigiata' or upright European hornbeam, grows to 40x20ft. Grows in sun to part shade. Plant in well drained soil; it is adaptable to many soils including clay. It doesn't have a central leader but fans out into a very densely-foliaged, oval-shaped tree making it ideal for use as a hedge. Has dark green leaves turning yellow in the fall and has smooth, gray bark similar to the beech. Blooms in March with white to yellow flowers. Because of its soil adaptability and narrow form this tree is often used on narrow building lots. I've seen it planted as street trees in Bel Air and it should be available in large sizes.

I love beech trees and I don't see them often enough in our landscapes. I'm trying to rectify this omission by using an appropriate beech tree in many of my designs. Here are some narrow-growing cultivars:

Fagus sylvatica 'Dawyck Purple' is a purple-leaved cultivar of the European beech with a columnar growth habit. It keeps its dark color throughout the summer. It is best planted in a sunny location.

Fagus sylvatica 'Dawyck Gold' is another columnar grower and has bright gold new growth that turns green in the summer. A second flush of growth in the summer makes a nice contrast of gold against the green, older foliage. Best planted in a sunny location.

These beeches work well as accent trees on any sized lot. They also make a nice front-of-the-home accent tree since they don't cover up the house front as the wider pear and cherry trees would. Plant in sun to part shade in moist, well-drained soil. All three grow to about 50x15ft after many years. European beeches are clay soil tolerant.

Ilex x meserveae 'Heckfee' or Castle Spire and Ilex x meserveae ╦ťHeckenstar' or Castle Wall hollies grow to 10x5ft. They are a new line of blue hollies that grow compactly. Castle Spire is the female holly, is pyramidal in shape, and has bright red berries and shiny green foliage. Castle Wall is the male holly with shiny green foliage and a more-upright form. Use in hedges, in foundation plantings, or as specimens. Plant in sun to part shade in moist, acid, well-drained soil.

Ilex x 'Rutzan' or Red Beauty holly is a new Rutgers introduction by Dr. Elwin Orton. It is a female holly with a dense, pyramidal habit, dark green leaves, and bright red berries. Grow in sun to part shade and in moist, acid, well-drained soil. This is a narrow pyramid growing to 12x4ft wide. Any male blue holly will pollinate it. We've purchased several small ones locally and I think they will do exactly what Dr Orton says they will do. Red Beauty is supposed to be a better berry producer than the Dragon Lady holly. This would be great used in foundation plantings, hedges, and in mixed borders.

Magnolia x 'Sunspire' grows to 40x6ft. Plant in sun to part shade in ordinary garden soil. It is tolerant of many soil conditions and takes heat and humidity very well. 'Sunspire' blooms in spring so the fragrant 4- to 6-inch gold flowers are not hurt by late spring frosts. I have not been able to find the parentage of this cultivar but I thought I read somewhere it was of M. virginiana origin. This would make a beautiful street tree or a tree for the corner of a tall house. By the way, as of the end of December, mine still has its leaves.

Prunus 'First Lady' is an upright-growing, early blooming cherry with dark pink, single, slightly pendulous flowers blooming in April. It grows to 25x15ft after 20 years. Plant in sun to part shade in ordinary garden soil. I've always liked its relative, the Okame cherry, and I'm sure I will like this new one as well. This is one of the first cherries named in the U.S.D.A.'s cherry breeding program to produce better cherries for our area. It has many uses in our gardens including as a street tree, small shade tree, and as a tree for house corners. This is a "Don Shadow Signature Collection" plant so it must be a great tree.

Rhamnus frangula 'Ron Williams', or Fine Line buckthorn, combines airy, ferny foliage with upright, slender growth. I liked this plant as soon as I first read about it. Fine Line is a low maintenance plant and adds a nice exclamation point among ground covers. Because of its hardiness, this is another plant to grow in containers, as well as in the garden. Grow in full sun to partial shade in any garden soil. Its fine green leaves turn a nice dark yellow in the late fall; actually, it's one of the last plants to drop its leaves. Grows to about 6x2ft.

Sorbus aucuparia 'Fastigiata' or fastigiate Mountain ash is another unusual shrub or small tree. 'Fastigiata' is an upright tree with strongly ascending branches, dark green leaves, and waxy red fruits. This is a slow-growing, coarsely branched tree. It has white flowers and, I hope, the large fruit clusters of its cousins. My plant is small and I have high hopes for it.

Taxus baccata 'Standishii' is an English yew cultivar. Plant in sun to shade in well-drained soil. It's very similar to the Irish Yew with a columnar habit but is slower growing. Its leaves are entirely golden yellow, and it is a low maintenance plant because it keeps its shape without trimming. Grows slowly to 30x8ft. Three of these plants would look great in a shady area with the dark-colored English yews growing around them.

Thuja occidentalis 'DeGroot's Spire' or DeGroot's Spire western arborvitae. I've been growing this plant in a fairly shady site and it's been doing very well. Grows to about 10x3ft. Plant in sun to shade. It prefers moist sites but does well on a fairly dry slope. Has nice, dark-green foliage.

Thuja occidentalis 'Yellow Ribbon' is a new arborvitae that has a narrow, very pyramidal form. Its yellow evergreen leaves remain yellow throughout the winter. This one tends to be the tallest of the arborvitaes listed here, being 12x3ft. Cultural conditions are the same as for DeGroot's Spire.

Thuja orientalis 'Beverly Hills' has bright yellow, soft, ferny foliage during the growing season. Winter color is said to be bright yellow green. Both of my plants are planted in part shade and are yellow green in the summer and turn brassy in the winter which is O.K. with me. Cultural conditions are the same as for DeGroot's Spire. This one grows to about 10x4ft. Note: Thuja orientalis might now be called Platycladus orientalis.

Pictures of many of these plants can be found on the internet.

Internet and Mailorder Nurseries: Forestfarm Greenwood Nursery - sells Don Shadow's Signature Collection Rarefind Nursery Spring Meadow Nursery, Inc. - wholesale grower but a great resource website for consumers Wayside Gardens Local Nurseries:

McLean Nurseries, 9000 Satyr Hill Road, Baltimore, Md, Phone 410-882-6714