Patriotic Plants: The Mighty Oak

July 4th is upon us – the day we celebrate the birth of our nation. Looking back to 1776, trees and the lumber they provided were a critical natural resource, providing the raw material for shipbuilding. While modes of transportation have changed in the 247 years since our independence was declared, trees are still an important symbol of our nation’s strength and identity.  

Their ongoing importance was recognized in 2004 when Congress passed legislation designating the Oak as America’s National Tree. The Oak was selected by a vote hosted by the National Arbor Day Foundation, in which Americans of all ages and from all walks of life chose the Oak over 20 other varieties of tree to be our national symbol.  

There are more than 90 species of Quercus, the Latin name for Oak, growing in the United States. They have been an important part of our national history and folklore. Did you know that the USS Constitution took its nickname “Old Ironsides” from the strength of its oak hull? 

Today, oaks are recognized as playing a crucial role in the ecosystems of our world:  

• Oaks lead the list of trees in providing food for insects, birds and other animals.  
• They support almost 900 caterpillar species across the US, far more than the number supported by any other genus.  
• Birds forage longer in oaks because those caterpillars provide high value food, especially for baby birds.  
• Animals such as squirrels and Blue Jays find acorns a rich source of protein, fat, and carbohydrates. 
• Leaf litter provides habitat for many beneficial organisms, supporting a diversity and abundance of life. 
• An oak’s canopy and root system are important in water filtration, helping rain percolate instead of running off, and purifying it in the process.
• Oak trees sequester carbon.

So many reasons to celebrate our national tree on our nation’s birthday! 

Blossoming Beauty: Exploring the Enchanting Trio of Hibiscus Varieties

In tropical climates any hibiscus can go right in the ground and turn into huge trees and shrubs that bloom more or less year-round. Here in New England, we enjoy a more modest tropical display, in both size and season. But even here in Massachusetts, the world of hibiscus is fascinating and worth a deeper look.

In the Bay State it’s important to know what kind of Hibiscus you’re getting and how you can expect it to behave. For our purposes, there are three types to consider: Tropical Hibiscus, Rose of Sharon, and Perennial Hibiscus.

Tropical Hibiscus

Tropical Hibiscus (Hibiscus rosa-sinensis) can be found in our greenhouse, or among the annuals during the warm months. This type of Hibiscus is hardy in USDA growing zones 10 and 11 (think Central Florida and further south from there). Here in zone 6, we can enjoy tropical Hibiscus outdoors through late spring and summer but they will not survive our winters and should be considered an annual plant. If you have a lot of sun in your home you could also consider it a houseplant and you can enjoy its gorgeous blossoms year-round!

There are thousands of cultivars of tropical hibiscus available today. A few notables include Red Hot Tropical Hibiscus, Chinese Lantern, Mahoe, and Fiji Island in addition to the traditional red varieties. In the Middle East and Africa, a popular drink called karkade is made from the dried flowers of red hibiscus. It can be drunk cold or hot and is said to have numerous health benefits and it is used to soothe ailments such as colds, high blood pressure, intestinal, circulatory, and skin disorders and more.

Tropical Hibiscus

Rose of Sharon Hibiscus

Rose of Sharon (Hibiscus syriacus) is a deciduous shrub hardy in USDA growing zones 5 through 9, good news, zone 6, we’re in! It will lose its leaves in the winter and put out new growth in spring. Very little pruning is required as these shrubs maintain an upright growth pattern.

These hardy shrubs bloom late into the season when little else is in bloom. They are low-maintenance and easy to grow and come in many forms including dwarf, columnar, upright, and tree form, and flowers can be single, double, or semi-double. You’ll find them in exciting and unexpected colors including reds, pinks, purples that are almost blue and even multicolor blooms. They are heat, drought, and salt tolerant (perfect for the Cape), deer resistant and a favorite of butterflies and hummingbirds!

Perennial Hibiscus

Perennial Hibiscus (Hibiscus moscheutos) is a fun one. Hardy in USDA zones 4 through 9 this hibiscus will lose all its leaves in the winter and resemble dead sticks come spring. Leave those sticks there through the winter months then, in the spring cut them all the way back, almost to the ground. Late May, early June you’ll start to see new growth come up from the ground and boy does it come up fast! Enjoy gorgeous blooms the size of your face all summer long!

Perennial Hibiscus

Pruning Spring-Blooming Shrubs

The spring flowers of Azaleas, Rhododendrons, Forsythia, Lilac and Viburnum are always so welcome after a long winter season. To ensure those beautiful blooms for next year’s spring, it is important to know when and how to prune them.  

Spring flowering shrubs bloom on “old wood,” meaning growth that took place in the previous year. Another way to think of it is, the flowers you enjoyed this year were formed in the summer of last year. The window of time to do any pruning is after springtime flowering but before next year’s flower buds form. If you need to set a reminder in your calendar, a rule of thumb is to prune no later than July 4th. If you prune in late summer or fall, you will be removing next year’s flowers. It is generally recommended not to remove more than one-third of a shrub’s mass in one year. The shrub needs the remaining two-thirds leaf mass to maintain its vigor and health. 

PRUNING MOST SPRING-BLOOMING SHRUBS

Pruning will control size, improve shape and encourage healthy branching. To shorten a branch, follow the branch down from the tip to the leaf you want to keep. Choose an outward facing leaf as this will direct the plant to make any future growth towards the outside, rather than encouraging further congestion in the inside of the plant. Make the cut one quarter inch above the topmost leaf you wish to keep.  

To reduce the height of shrubs such as Forsythia, remove the tallest canes by cutting them out at ground level. Thin out any canes crowding the center to allow light and air to reach the interior. Remove canes growing in an unwanted or unruly direction. 

Use this method to maintain your spring bloomers as needed. Read on for particular pruning methods that may become necessary if your lilacs or forsythia become truly overgrown.

PRUNING OVERGROWN LILACS

While the pruning principles above apply to a reasonably sized lilac, we often find ourselves with a shrub that is far too large. After all, don’t we want the flowers at a level where we can bury our faces into that heavenly fragrance? 

The technique of “rejuvenation pruning” will bring an unruly lilac back to a manageable size. The preferred time for rejuvenation pruning is just before bud break in early spring (late March, early April) but it can be done any time in the spring or summer. In the first year, cut one-third of the oldest, most unproductive stems down to the ground. The next year, take out another third of the old stems, again at ground level. In the third year, remove the remainder of the old stems. New productive stems will quickly replace the old wood. While it takes three years to complete, the shrub stays attractive throughout the rejuvenation period. And after three years you have a brand new shrub. Maintenance pruning in the following years will keep flowers at a height where they can be best appreciated. 

PRUNING OVERGROWN FORSYTHIA

Forsythia, which is a vigorous shrub, can be cut completely to the ground if it is wildly overgrown. New shoots will form and grow into stems. In the second year, select the strongest of the new canes and prune out the weaker ones. In the third season, begin an annual maintenance pruning regimen. 

Hydrangeas in All Their Glory

Can you think of a more beloved plant in New England than the Hydrangea? Its flowers have many forms, ranging from beautiful rounded mopheads in shades from light blue to rich, almost purple blue; to showy panicles in shades of pink and white; to delicate lacecap flowers in tones of pink and blue. New varieties are expanding the range of flower color into the red spectrum. In terms of size, there are varieties ranging from 2ft to 8ft in height. Some varieties can even be grown in containers. And the climbing hydrangea is as beautiful as it is unusual. Some varieties are also available in tree form. This means there is a hydrangea for every location!

Hydrangea macrophylla “Twist n’ Shout”

There are 6 species of Hydrangea commonly grown in our area: 

• Hydrangea macrophylla, perhaps the most familiar to us when we think of Hydrangeas 
• Hydrangea paniculata, increasingly popular for its reliable blooming habit 
• Hydrangea arborescens, the most shade tolerant of all Hydrangeas 
• Hydrangea serrata, the hardiest of hydrangeas, whose elegant lacecap flowers are like jewels in the garden 
• Hydrangea quercifolia, with its striking oak leaf shaped leaves 
• Hydrangea petiolaris, which will climb fences and trees 

For more information about each of the 6 species of Hydrangeas, including information about when to prune, see our Hydrangea Plant Care Guide. 

Hydrangeas come into bloom just as the first flush of roses is fading. Beginning in late June and continuing into the fall, they offer a strong presence and a long season of interest in the garden. The flowers subtly change color as they mature, often remaining on the plant into and through the winter, fading to a lovely tan color. The stems of the plants remain upright through the winter, adding structure and form to the winter landscape. 

Hydrangea flowers and interest to the landscape even in winter!

We love Hydrangeas for the wonderful show of flowers they provide. However, in some years, winter conditions can affect that show. In harsh winters the dormant flower buds may be damaged, either by extreme cold or by an unusually warm period followed by a sudden return to frigid conditions. Temperatures of minus 10-15 degrees, which we experienced in early February 2023, combined with a lack of insulating snow cover, may mean a diminished show this summer. 

Plant breeders are doing wonderful things to improve the performance and increase the varieties of Hydrangeas available to us. They have a bright future. And a long past. Hydrangeas have been found in fossils from 45-60 million years ago!  

When in season, select Hydrangeas are available on our online store for pick-up and local delivery!