Forsythia is a shrub that heralds the arrival of spring for many people. The newer cultivars have upright and arching branches that are laden with golden-yellow blooms. A cool spring could extend the blooming time for Forsythia for more than four weeks during late April and May. There are even forsythia that bloom reliably in colder regions. The early forsythia cultivar called ‘Ottawa’ is hardy to minus 32 degrees Celsius (about the same in Fahrenheit). The most popular forsythia is ‘Lynwood’ which has long arching branches that could reach 9 feet (3 metres) in length and flowers that are a rich yellow color. If space is a problem, consider the dwarf green-stem forsythia, with primrose yellow blooms called ‘Bronxensis’ that is only 1 foot (30 centimetres) tall.
To keep forsythia blooming well, prune out about one-third to one-half of the oldest branches immediately after it has finished flowering. This will encourage healthy new shoots to grow during the summer. These will be your flowering branches for next spring. Forsythia are dramatic in the garden during the winter when their tall and straight or arching branches create a haystack look. To accentuate the tan color of the twigs and the magnificent blooms, place forsythia where it has a dark green backdrop of conifer foliage. Forsythia can be used as a natural hedge, as a mass planting in a shrub border, or even as an espalier plant growing against a wall (as can be seen at Oaks Garden Theatre in Niagara Falls, Ontario Canada). In most cases, give them room. Some forsythia can grow to be over 9 feet (3 metres) tall and most importantly, the same width. For the best blooms, prune forsythia to rejuvenate it and grow it in the full sun.
One of the most popular of all shrubs is the Koreanspice viburnum, (Viburnum carlesii). Blooming for 10 days in early May, this shrub has an unforgettable sweet fragrance that produces a response similar to aromatherapy. The plant is also very beautiful in flower. The white flowers are shaped like snowballs and decorate the entire shrub. The shrub is a slow grower and will probably reach its ultimate height and width of 5 feet (1.2 metres) after 15 to 20 years. It is not fussy about soil – any reasonable garden soil will do. One of the advantages of this plant, are its tough leaves, which make it undesirable as food for the pesky viburnum leaf beetle. Plant this shrub where it will receive sun for most of the day and where the fragrance can waft into an open window. Even though it is well worth growing just for its fragrance and attractive blooms, this plant has nice red fruit and an interesting structural form.
The common spicebush, (Lindera benzoin) is a native shrub found growing in many Northeast US and Southern Ontario swamps and woods. Spicebush is a treasure waiting to be discovered by gardeners and unfortunately is rarely found in mainstream nurseries. Possibly the reasons that Spicebush is not readily available is that it is difficult to transplant and it is slow-growing. Purchasing plants that have been container-grown will increase its chances of survival. This shrub has small clusters of yellow petal-less flowers tightly pressed along the branches which open early in the spring even before the leaves unfold. The best feature of this plant is the spicy fragrance emitted by all parts of the shrub when rubbed or scratched. Many parts of spicebush are reputed to have some herbal properties. The seeds from the female plant were used during the American Revolution as a substitute for allspice (which was not available from England). The twigs and leaves were used during the Civil war as a substitute for foreign teas. Spicebush also is used as food for wildlife. Birds will eat the fruit and deer enjoy munching on the twigs. Another interesting feature of this plant is that it is either male or female. If it is female, it will have small, round, bright red fruits just under 1/2 inch (1 cm) in diameter that are most visible after the leaves drop in the fall.
Native plants have so many good attributes that it is incomprehensible that they are not used more in gardens. Spicebush is almost pest-free and disease-free and is happy growing in heavy, alkaline, clay soil. It can be used as a tall visual screen to block undesirable views or it can be used as an understory shrub in a partly-shaded location. In the fall, this shrub has foliage that is a brilliant golden-yellow color.
Cornus mas, or Cornelian cherry, has flowers that are similar to Spicebush but has the advantage of being even more showy. Cornelian cherry has small, yellow, petal-less flowers which bloom before the leaves emerge. It is also one of the first shrubs to bloom in spring. It has the look of a light, airy, yellow cloud. The blooms are so early that it blooms even before forsythia. The flowers form the previous fall and are protected from the harsh winter by a hard covering. When they bloom they stay open for about 3 weeks during April. A cherry-sized fruit forms during the summer and turns bright red when ripe. This edible fruit is highly prized by birds. The fruit is not as showy as it should be since it is hidden in the leaves. Some gardeners (with patience) have cooked the fruit and used it in making preserves. This Dogwood family member is adaptable to many soil types and tolerates city conditions well. It can grow in full sun or partial shade. Its main requirement is space. Ultimately it will reach 18 feet (6 to 7 metres) tall and grow almost as wide. This hardy shrub can be used in large shrub borders or in mass groupings for large properties.
Another excellent shrub which has edible fruits that are prized by birds and gardeners is the Saskatoon serviceberry (Amelanchier alnifolia). This multi-season shrub has attractive white blooms in May, edible fruit in July, reddish foliage in the fall and smooth grey bark in the winter. The juicy, purple-black fruit resemble (and taste like) blueberries if you can beat the birds to the ripening fruit. The serviceberries make excellent jellies and pies. Serviceberry blooms reliably with lots of delicate five petalled white blooms in early May. This shrub blooms well in full sun or in a partly shaded location. Be wary that hot, dry weather will shorten the blooming time of this shrub to about one week. Serviceberries have a nice red-orange fall foliage and can be grown under taller trees. It can also be used in groups for a massed effect. The smooth gray bark of this upward spreading shrub is attractive during the winter.
Several other shrubs deserve special attention. Exochorda (Pearlbush) has beautiful, pure white, showy flowers which open when the horsechestnuts are in flower. The branches gracefully arch to the ground on this 5 foot (1.5 metre) high plant.
Carolina Allspice (Calycanthus floridus) is a native shrub that has very interesting fragrant maroon-chocolate blooms. The flowers are the size of a quarter and are a pleasant surprise for anyone who travels near this plant in May. It is a native shrub that should be used more often in gardens.
There are two groups of plants that have not been included in the best-shrubs list. Many would expect that Magnolias should be placed in this group. They are not included because of severe pest problems caused by the Magnolia scale. This devastating insect is big trouble for unprotected plants. Until it is under control, watch your Magnolias. The other group of plants that many would expect to be on this list are the Spirea. These plants have been the mainstay of our gardens for decades – perhaps too many decades. They are overused and until a dramatically new introduction arrives, they should hide in the background. They do have some great attributes, but they are tiresome and have an old fashioned look.
Remember, the best shrubs are the ones with multi-season interest. Consider how a shrub will look for the remaining fifty weeks after it finishes flowering.
All images used from www.wikipedia.com under the Creative Commons Share Alike license. Authors: Cornus mas (Bouba), Calycanthus floridus (Ulf Eliasson), Viburnum carlesii (Rudiger Wolk, Munster), Amelanchier grandiflors (Kurt Stuber).