Author Archives: Jeff


Natural Setting for Hemlock Screening

“If Pennsylvanians were to select one tree as characteristic of our state, nothing would be better than Hemlock.” So wrote Dr. Joseph T. Rothrock, the “Father of Pennsylvania Forestry,” in 1896. In the mid 1800s Pennsylvania was number one in the country for lumber production and hemlock made up two thirds of that production. This majestic native not only provided wood for homes, but the bark is very high in tannin with is used in the tanning industry ever since it started in this country. On June 22, 1931 the hemlock was adopted as the state tree of Pennsylvania. The eastern hemlock is found in every county in Pennsylvania, but is most common in mountainous regions. The father of landscape gardening in America A. J. Downing felt the hemlock was the most picturesque and beautiful of the worlds evergreens. This plant has a very open conical shape with very dense foliage and branching down to the ground.

Alot of hemlocks planted in our Urbain areas today are very much in decline. There are two reasons for this. the first is when hemlocks were taken from there natural environment (growing along cool creeks and streams in very organic soils) and planted in urban areas were the top soil was striped and taken away. Then planted in hard packed clay soils that tend to dry out in the hot summer. This is not an endowment the hemlock can survive in. The second cause of decline is Hemlock woolly Adelgid, this is a small insect that looks like white cotton that attaches to the bark at the base of the needle. Damage is done when this insect inserts its piercing and sucking mouth into the base of the needle and removes fluids. This will cause reduction of plant health, Severe infestations will result in needle drop, die back and death of the tree. The best time to spray an insecticide to control this insect is September though October to try to kill as many adult females before overwintering. Also spring soil injections of a systemic insecticide will give you much longer control of this insect. Although these are very good controls for this insect in our ornamental, this insects continues to devastate our forests of Pennsylvania.

Amsonia Hubrichtii

Photo Credit: Melanie Blandford

Amsonia Hubrichtii has been voted perennial plant of the year by the perennial plant association for some very good reasons. This perennial is a plant for all seasons, with its mounding almost arching growth habit, it is great for a border garden or open woodland. This plant is best planted in large masses, it likes full sun to partial shade. Amsonia prefers well drained soils and will tolerates less moisture. As it gets established it will tolerate drier conditions. Arkansas blue star as it is known has a upright mounding growth habit with its narrow willow leaf and a slender round seed pod. With its Powdery blue star like flower clusters at top of a 2-3 foot stem in early spring to the beautiful display of fern like foliage in summer. As November roles around the foliage turns to a golden yellow, This is one of the best fall shows for a herbaceous perennial. Another Amsonia to try is a variety called “Blue Ice” This is a much smaller plant only getting to 15-18 inches tall and a much longer bloom time. This smaller compact plant should also be used as a edging or border plant.

Early bloomers

Star Magnolia

Star Magnolia is the early est blooming magnolia in southeast Pennsylvania. This slow growing deciduous shrub to small tree produces a very showy white flower late March to early April. The fuzzy bids open before the foliage appears producing a 3-4 inch white fragrant flower. Because it does bloom so early frost and cold winds tend to blacken blooms and fall off sooner. This plants slow dense growth habit makes it excellent for a small garden. This Multi stemmed tree has a light gray color on main trunks, the younger twigs have a dark brown color. Star Magnolia need very little pruning unless you are looking for a tree form, that only involves lifting the lower branches to expose the multi able trunk. All pruning should be done after plant has bloomed in spring to not inter fear with next years bud Set.

Cornus mas

Another excellent early blooming tree is cornus mas, The common name is Cornelian cherry dogwood. This is also a large deciduous shrub to small ornamental tree. The small clumps of yellow flowers appear late winter early spring before the foliage emerges. Can be trained to become a small ornamental tree by lifting lower branches to expose multi stem grayish brown mature trunks. The deep green almost oval shaped leaves turn slightly purple color in fall. Very clean tree, no real insects or disease problems.

Prunis Okame

This one of the ear lest blooming Cherry’s in our area. It has a tight upright growth habit that rounds off as it matures. Has very showy reddish-bronze bark that stands out in any landscape. The small pink flowers emerge before the foliage but do not tend to last real long because of rain and cold weather this time of the year.This plant is sometimes used as a street tree or in parking areas because of its tight upright growth habit, its also good for small gardens and hedge row plantings. It has oval shaped leaves that are dark green in color during the summer and develops a rather good fall color of orange and copper. This is three good choices for small early blooming ornamental trees that would look good in any ones garden.

Weed Control


One of the most time-consuming jobs in our landscapes is trying to keep our lawns and gardens free of weeds. There are a number of chemicals that are available to use to help with this pain-staking chore. Most of us do not like using any more “chemicals” around our properties than we have to, for fear of them being toxic to our kids, our pets, and the environment. Pre-emergent herbicides have been put under stringent tests by environmental organizations and no safety issues have been found with these products. If you would compare these tests with the same tests done on common table salt you would be very surprised. There are some terms we need to discuss when talking about herbicides. They are:

· Pre-emergent
· Post emergent
· Selective
· Nonselective

These are all terms to describe how synthetic herbicides work to control unwanted plants or weeds. A pre-emergent herbicide will affect the tiny first roots of seedlings thus preventing them from growing, while post emergent herbicides are used on weeds that have germinated or hard to kill weeds such as Canadian thistle. Selective herbicides are used to remove some species of plants and not others. A nonselective herbicide will kill any plants it is applied to; a good example of this is Roundup. While all herbicides help to control weeds, knowing what type of weeds you need to eliminate will help you in selecting the right products to use. Contact us at River Valley Landscaping and we can help you design the right program to achieve optimum weed control.


For best results when using pre-emergent herbicides timing is everything. These products should be applied several weeks before germination, and watered in after application so this material can move in the top inches of soil to create a weed barrier. Weed seeds will germinate when soil temperatures are consistently over 50°F. Some gardeners prefer to apply pre-emergent before the Forsythia blooms. In southeast Pennsylvania pre-emergent herbicide should be applied around the 15th of March to control spring and summer weeds and reapplied by September 15th to control fall and winter weeds.

These chemicals can be applied any time during the growing season to control ungerminated seeds. Pre-emergent products have a life of between 60 and 90 days depending on the amount of moisture and soil content. Multiple applications can be made, be sure to read the label so you are not over applying beyond the recommended rates. These products can build up in the soil if overused and can burn root system of many plants.

Preen vs. Snapshot

Preen is a pre-emergent that is found in a lot of garden centers and box stores in the area. Trifluralin is the active ingredient in Preen; it is also the active ingredient in Snapshot but at a much higher rate. Snapshot also has another active ingredient Isoxaben, which gives this product extra protection against some difficult weeds and grasses. Snapshot is the preferred choice of many nurseries and landscape companies because of its wide label. Only select dealers sell these professional products in larger quantities. If you analyze the price of the two products, Snapshot is cheaper per 1,000 square feet and has that wider label.

One of the hardest weeds to control is Nutsedge mainly because one single weed is capable of dropping thousands of seeds. Knowing how to identify this weed and its life cycle is very important in its control. There is a pre-emergent herbicide labeled just for this weed called Freehand.

Since March is not a very busy time in the garden, set aside some time to apply some pre-emergent or contact us at River Valley Landscaping to have it professionally applied for you. Pre-emergent herbicides will not control 100 percent of your weeds, but it should reduce the amount of hand pulling and the amount of more toxic post emergent herbicides you should have to use. Giving you more time to sit back and enjoy your garden.

Perennial Plant of the year

The Perennial Plant Association has chosen Baptisia australis or False Indigo as this year perennial plant of the year. This is a very hardy plant that tolerates a wide range of climates. Native to river banks from Vermont south to the Shenandoah Valley.

Its blue to purple upright flowers stand out in the garden, Although it only blooms 3 to 4 weeks in late spring to early summer the brilliant colors makes it totally worth it. False Indigo will grow to 3 to 4 feet and spread just as wide, it will grow in full sun or part shade, it can tolerate dry to medium soils and is very drought tolerant. Large black seed pods set in after flowering giving this plant another interesting element. This plant attracts butterflies and is also great for cut flowers and dried flower arrangements. Because it is a self seeder this perennial is best used in border gardens, meadow gardens, woodland gardens, or cottage gardens as it does naturalize very nicely in native soils. We are all looking for plants that are low maintenance and this one certainly fits that. It really is border line between perennial and shrub and has a tendency to flop open in the center, the only real maintenance needed is cutting back in fall or early spring. So take a look at the beauty and features of this outstanding perennial.

Metasequoias (Dawn redwoods)

Dawn redwoods are in a small class of trees known as deciduous conifers. This means it does produce an evergreen type needle but it looses it every fall, also in this group are baled cypress and larch. One of the interesting facts about this group of trees is that they are regenerative, this means that if you were to cut down a dawn redwood it would regrow from the stump to form a new leader. The root flair of this tree is one of the most outstanding parts. With its orange/brown color it produces several large buttress like root flairs that extend several feet up the trunk. This tree produces small upright spreading branches that are well attached to a straight central trunk. This tree requires very little pruning to keep its pyramidal form. Optimal growing rate for this tree is about seven feet a year, for that you will need full sun, lots of deep ground water and a well drained, acidic soil. Many dawn redwoods in this country that are less than fifty years old have already reached the 100 foot mark. Although it is a very fast growing tree, it does not like to be crowded among other trees, it will not do very well in that situation at all. The lacy green fern like foliage that comes out in spring and lasts though the summer months turns a yellow /orange color after the first frost. Like the baled cypress it will grow in standing water, so it is a very good plant for wetland areas. Lighting protection is recommended for older trees since they are usually the tallest trees and would be the first ones hit. So if you are looking for a large mejestic giant for your garden give this plant another look.


Hellebore are often called Lenten Rose or Christmas rose, these evergreen perennials are almost a staple in the winter garden. This plant was named 2005 perennial plant of the year by the Perennial Plant Association. The flower color range from pure white to plum, bordering on black also yellow, pink, and red. They come in single to semi-double, and bloom from late winter to late spring some lasting two months or more. These plants have a clumping growth habit and get to 24 inches tall and 30 inches wide. Although sold as shade-loving plants these plants can take a lot of full sun and range into deep shade. This plant will thrive in a wide range of soil conditions, they are often found native in alkaline soils, but adapt to very acid woodland soils. When installing new plants pick a well drained site this plant does not like to be water logged, but it is very drought tolerant. Incorporate lots of organic material and plant like any other perennial. Long term exposure of this plant to the skin can cause a reaction that can last for a few hours, so when handling this plant wear gloves. One good thing from this is deer will not eat it so your hellebore will not become a salad buffet for foraging deer. The best way to reproduce this plant is by division that way each plant is identical. This plant will propagate its self by dropping seed to the ground around the parent plant, this seed will take 2 to 3 years from seed to flower. The Lenten rose will respond well to many different conditions, hellebore will make a fine addition to any garden.

Red Chokeberries

Red Chokeberry is a native plant to North eastern America, It was found growing in wet woods and wetlands. Chokeberries are attractive ornamental shrubs, naturally understory and woodland edge plants. Because they are native plants they are insect, pollution, and disease resistant. There are two well known species named for there colored fruit, red and black. This plant is a multi stemmed shrub, 6-12 feet tall and spreads readily by root sprouts. This is truly a plant for four seasons, in spring it produces clusters of white, five petaled flowers. They give way to dark green foliage throughout the summer months. This foliage turns from a lush green to a orange/red that really stands out in the fall garden. Also appearing are the bright red, pear shaped berries. These berries persist on the plant though December and January and along with the reddish brown exfoliating bark really standout in the winter landscape. Although the fruit persist though most of the winter, they are occasionally eaten by game birds and song birds and reportedly by bears. Because this plant is self pollinating only one plant is needed to produce berries. The juice from the berries is not sweet but is high in vitamin C and antioxidants. The berries can be used to make wine, jam, syrup, juice, soft spread, and tea. So if you are looking for a plant to spruce up your winter garden, give this plant a try.

Winter King Hawthorn

One of the showiest ornamental trees for the winter garden is Winter King Hawthorn. The orange/red fruit which persist on the naked tree throughout the winter makes this a tree anyone would want in there garden. Unlike other hawthorns it has has very small thorns that are inconspicuous. Also unlike other hawthorns this plant is somewhat disease and pest free. This small to medium size tree will get to 20 to 30 feet in height and width. That makes this tree a good choice for small gardens, it is also a very good tree in urban areas were air pollution, poor drainage, compacted soils, and drought are common. The 2 inch clusters of white flowers that open in mid May, show up very nicely against the glossy green foliage. The outer bark of this hawthorn is beige-gray, which exfoliates to expose a warm cinnamon color under bark. The younger branches are a silver-gray color, bearing 1 inch thorns. The fall color although not its primary feature turners from green to a golden yellow, with hints of red and maroon. For winter interest, this is a plant that’s hard to beat.

Caring for Poinsettias

Poinsettias make up for 85% of potted plants sales during the holiday season. Lastyear poinsettias amounted to $220 million in sales in the United States alone. Poinsettias are grown in all 50 states, with over 100 varieties available. Most poinsettias are grown from cuttings, these cuttings are stuck in mid to late summer and are grown to full mature plants in only a few months. This is best selling flowering potted plant in the United States, over 75 million sold and most within a six week period. The most popular color sold is red followed by pink and then white.Poinsettias are not poisonous if eaten, however some people may get a skin irritation from the milky sap. After you make your selection, make sure the plant is wrapped properly because exposure to low temperatures even for a few minutes can be damaging to this fragile tropical plant. When getting the plant home carefully unwrap it, place it in indirect light. Six or more hours of light daily is ideal. Keep your poinsettia away from warm or cold drafts; it likes daytime temperatures around 60 to 70 degrees and and night time around 55. Check soil for moisture, do not leave plant dry to wilting this tends to drop leaves sooner. Be sure to punch holes in foil so water can drain into saucer. Discard excess water in saucer these plants do not like to be water logged.A fresh poinsettia is one on which little or no pollen is showing on flower cluster in the center of the bracts. Plants that have shed there pollen will soon drop there colorful bracts. Most poinsettias are bought as seasonal annuals, if you are going to try to keep this plant after the holiday start fertilizing this plant after it stops blooming. Fertilize once a month with a water soluble houseplant fertilizer. Move poinsettia outdoors when danger of frost is passed. Place in a sunny area but were it will get moderate shade in the afternoon. To get the plant to re flower you will have to keep it in total darkness between 5pm and 8am. Starting around October 1 and continue until color shows on the bracts.