Fast Growing Landscape Plants
Fast-Growing Landscape PlantsBy George Weigel, Pennsylvania Certified Horticulturist (PCH)
When you're in a hurry
How to get a mature landscape in less time
In most new housing developments, the land is scraped clear and regraded into streets and building lots. The good news is that you're left with a clean slate so you can plant the kind of landscape you want without first having to undo someone else's overgrown mess. The bad news is that you'll have to wait years until this new landscape looks like much.
While the inside of new homes can quickly be made to look "lived in," it's not so easy on the outside. What most new home-owners do is go to the garden center and ask for the fastest-growing things they can cram into the car. Usually, they end up with a maple tree or two for shade and a trunk full of arborvitae or Leyland cypress to screen off the deck or property line.
That might work for a little while until the seamier side of some of these quick-starts begins to emerge.
When faster isn't better
Plants like the silver and Norway maples are notorious rooters that not only choke out grass but push up nearby sidewalks, lose limbs from their weak-woodedness and don't know when to quit getting bigger. Willows and poplars also are speedy growers, but they're even more brittle-wooded as they age. Arborvitae tend to send up multiple leaders that are prone to splitting apart in snow storms, and Leyland cypress get increasingly gangly by their teen-age years.
Sometimes the overwhelming desire to get something in a hurry turns out to be bad news to more than just you.
If you didn't know how big a plant was going to get and planted it too close to the property line, your neighbors could be angrily knocking on your door when your branches end up hanging onto their land.
Sometimes, homeowners plant for today even when they know they're creating trouble later. Part of it is because people want screening or shade now, not when they're ready to retire. But also a factor is how fast so many people move in and move out of homes these days. Those who plan to move in a few years may not care about a plant invading the neighbors or swamping their own deck later.
One option for immediate impact without trouble later is to plan for the mature size but to buy as big of specimens as your budget allows. Be aware that bigger plants can cost significantly more, are much more difficult to move and generally don't adapt to transplanting as well as smaller specimens. But if the transplant is successful, your landscape will look a lot more mature than it really is. This might make the most sense with just a few trees and maybe that privacy planting that's so important to many home-owners in developments.
Another way to get quick impact is to carve out one or more large, flowing garden beds. Anchor the bed with one or more trees and/or large shrubs and fill the rest with masses of low shrubs, perennials, bulbs and groundcovers. In a year or two, these gardens will look full.
No matter what you plant, don't skip the all-important factor of good soil. In poor-quality or low-nutrition soil, even fast-growing plants are not going to grow very fast. They may even die, forcing you to start over.
It's always a good idea to do a soil test before planting to determine exactly what kind of fertilizer, lime or sulfur you'll need to add — if any.
Working a few inches of compost into the top 10 or 12 inches of your beds also will help young roots to get off to a good start. When land is heavily graded, the soil structure is damaged, and you may even be starting with subsoil only a few inches below replaced topsoil. The slightly raised beds that result from adding organic matter give roots a little extra "breathing room" and help alleviate potential rotting that can occur in poorly drained subsoil. Working a little mycorrhizal fungi (now available under several brand names in the fertilizer section of most garden centers) also can help get young roots off to a good start.
Also be sure to keep all new plants well watered so that the soil around and to the bottom of the rootballs is consistently damp. Top your beds with 2 or 3 inches of organic mulch (wood, bark, chopped leaves, etc.) to hold down weeds and to keep moisture in the soil.
Shade, impact and privacy
For fast shade, good alternatives to the silver and Norway maples are the Freeman maple 'Autumn Blaze' (Acer x freemanii) and red maples 'Red Sunset' and 'October Glory' (Acer rubrum); 'Heritage' river birch (Betula nigra), the fruitless sweetgums 'Cherokee' and 'Rotundiloba' (Liquidambar styraciflua); katsura tree (Cercidiphyllum japonicum), and some of the new, Dutch elm disease–resistant American elm hybrids that are starting to show up in garden centers.
For impact in bigger areas, consider planting a triangular minigrove of three of one species. Birch, maples and serviceberries (Amelanchier) work especially well in groups.
To screen out the peering eyes of neighbors, go with the improved 'Emerald Green' cultivar of arborvitae or consider other fairly narrow evergreens such as the Serbian spruce, Hinoki cypress, columnar Norway spruce, upright junipers or 'Dragon Lady' or 'Red Beauty' hollies. Screen plantings don't have to be a wall of one type of evergreen either. Plant two or three different kinds in patterns or mix evergreens with small, multistemmed flowering trees such as the American fringetree, Kousa dogwood, serviceberry or sweetbay magnolia.
Don't overlook hardscaping such as walls, fencing, pergolas and trellises as other options for getting instant screening. Fast-growing vines such as the sweet autumn clematis, honeysuckle, trumpet creeper and Boston ivy can be used to soften these structures.
There are even some big annuals, perennials and tropicals that can add instant impact to a new landscape. Good examples are sunflowers, elephant ears, castor beans, banana plants, cannas, ornamental grasses, hibiscus and tithonia (Mexican sunflowers).
Then there's the option you probably don't want to hear — patience.
Your plantings might not give you the immediate impact that your living room furniture does. Then again, you won't have the enjoyment of watching your sofa grow up and get better with age.
Some reasonably well behaved fast-growing plants that do well in Pennsylvania
American elm hybrids (Ulmus americana)
Atlantic whitecedar (Chamaecyparis thyoides)
Douglas fir (Pseudotsuga menziesii)
Goldenrain tree (Koelreuteria paniculata)
Green ash (Fraxinus pensylvanica)
Japanese pagodatree (Sophora japonica)
Katsura tree (Cercidiphyllum japonicum)
Korean mountain ash (Sorbus alnifolia)
Larch (Larix decidua and kaempferi)
Mountain ash (Sorbus aucuparia)
Norway spruce (Picea abies)
Ornamental pear (Pyrus calleryana)
Pin oak (Quercus palustrus)
Redbud (Cercis canadensis)
Red maple (Acer rubrum)
Red oak (Quercus rubra)
River birch (Betula nigra)
Sawtooth oak (Quercus acutissima)
Sweetgum (fruitless) (Liquidambar styraciflua)
Tatarian dogwood (Cornus alba)
Thornless honeylocust (Gleditsia triacanthos inermis)
White birch (Betula papyrifera)
White pine (Pinus strobus)
Yellowwood (Cladrastis kentukea)
Abelia x grandiflora
American elder (Sambucus canadensis)
Beautybush (Kolkwitzia amabilis)
Bluebeard (Caryopteris x clandonensis)
Butterfly bush (Buddleia davidii)
Chastebush (Vitex negundo or agnus-castus)
Crape myrtle (Lagerstroemia indica)
Euonymus fortunei and japonicus
Forsythia x intermedia
Japanese kerria (Kerria japonica)
Lilacs (Syringa vulgaris)
Leyland cypress (Cupressocyparis leylandii)
Mock orange (Philadelphus species)
Ninebark (Physocarpus opulifolius)
Privet (Ligustrum species)
Purple beautyberry (Callicarpa dichotoma)
Red buckeye (Aesculus pavia)
Redosier dogwood (Cornus sericea)
Rose-of-Sharon (Hibiscus syriacus)
Scarlet firethorn (Pyracantha coccinea)
Scotch broom (Cytissus scoparius)
Sweetbay magnolia (Magnolia virginiana)
Virginia sweetspire (Itea virginica)
Hardy kiwi (Actinidia kolomikta)
Honeysuckle (Lonicera species)
Trumpet creeper (Campsis radicans)
Virginia creeper (Parthenocissus quinquefolia)