Month: September 2020

Agave Americana

 

November is a notoriously finicky month in my region; a mild autumn day can become a freezing night with little warning. If I’m not on my toes, this can be fatal for tender houseplants and tropicals left out in the garden. In the past, a day’s warning was sufficient for gathering all the plants to stow away in my garage or lathe house for winter. But my hectic travel schedule has forced me to become better prepared. I’m not always home when Old Man Winter strikes.

If I had to describe my usual level of preparedness, I’m more like Aesop’s live-for-today grasshopper rather than the plan-for-tomorrow ant. But I’ve learned incorporating a little vigilance into my lifestyle is better than to coming home to a frostbitten garden.

My greatest anxiety always centers on my Agave americana ‘Marginata’, or century plant. Purchased at an end-of-the-season sale, this plant has grown into an important focal point in my garden. The form and color are so interesting, that your eye is immediately drawn to it. The spiky, succulent blades can reach lengths of over 6 feet and often curl gracefully making the plant look somewhat like the head of Medusa.

Agave americana can take a certain amount of cold (41 degrees F), but the combination of sudden and extreme drops in temperatures and high rainfall is too much for it.

When I bought my agave it fit in a 1-gallon container and I simply kept it on the kitchen table during winter. Since then it has grown into a 4-foot tall behemoth with a cluster of babies gathered around the base. And while the blades are beautiful from a distance, they have sharp spines and tips. The thought of moving it produces a high level of procrastination that is only surpassed by my fear of losing it to cold weather.

So with the help of a close friend and thick gloves, I should have my agave tucked away in the garage by the end of the week, well before the first hard freeze. With this task out of the way, I can relax, enjoy the final days of autumn, and be the grasshopper that I truly am.

 

Evergreens

When guests stroll through my garden during the height of summer it is highly unlikely that they notice the many evergreens planted among the more showy flowers and foliage, but as the leaves begin to fall in autumn, these workhorses emerge from behind the scenes to reveal the real secret of my garden’s design.

There is a lot more to an evergreen than just year-round foliage. These plants can serve as garden walls, privacy screens, focal points, and points of punctuation. It could be said that evergreen plants are some of the most important in your garden because they possess both form and function.

As we transition from autumn to winter, the structure of your garden becomes more apparent, which makes it a good time to evaluate where you could use a few evergreens to bolster the framework. The first thing to consider is what type of structural element is lacking. Do you need a point of interest in an area of your garden? How about a hedge to create privacy or to screen out an unpleasant view? Maybe you could use a low border of green to frame a bed of flowers? The type of structural element you need will be a guide to the size and form of the evergreen plants to consider.

Next, decide what type of evergreen will best suit the conditions where the plants will grow.  What are the extremes of temperatures (heat and cold) in your area? Will the plants be in full sun, shade, or a little of both? Would you say the area is moist or dry?

Another consideration is the form of the plant you want (weeping, conical, spreading, etc.), and the plant’s growth rate (slow or fast). It is also a good idea to know the size the plant will reach at maturity.

Below I’ve created a chart to help you get started in your search for the perfect evergreen for your garden.   This is only a partial list. There is a whole world of evergreens to be explored. I suggest you visit your local garden center to see what they have that may be unique to your area.

 

PlantCultural NotesFormFunctionAttributes
Italian Cyrpess

(Cupressus sempervirens)

Zones 8 – 10; any well-dreained soil in full sun; shelter from cold, dry windColumnar, from 3 – 20 ‘ wide x 20 – 70’ tall depending on variety, good for formal gardensprivacy walls, focal points, punctuationsOne of the best evergreens for creating an illusion of enclosure without creating a solid wall.
Camellia sasanquaZones 7 –8; moist but well-drained, humus rich, acidic soil; partial shade; established plants will tolerate full sun, shelter from cold, dry wind.Upright, full, 10’ wide x 20’ tall, good for both formal and informal gardensprivacy walls, screens, focal pointsAutumn blooms are a bonus to this shrubs glossy, deep green foliage. For greater cold tolerance try one of the Ackerman hybrids. Excellent as a solid hedge to create privacy. Also works well as a focal point.
Hick’s Yew

(Taxus x media ‘Hicksii’)

Zones 4 – 7; plant in full to partial shade, well-drained soil. Will not tolerate wet feet.Upright, columnar, 3 – 4’ wide x 10 – 12’ tall, good for both formal and informal gardens, slow growingscreens, low borders

 

An excellent shrub for creating the walls of your garden rooms. Yews are a favorite in English gardens. All parts of the plant are poisonous. Narrow, needle like foliage is a nice, glossy dark green.
Ilex ‘Nellie R. Stevens’Zones 7 – 9; grow in moist but well drained, moderately fertile, humus rich soil in full sun to partial shade.Upright, columnar, 10’ wide x 10 – 20’ tallprivacy walls, screens, focal points, punctuationsI use this shrub as an evergreen wall around my fountain garden. Fast growing with dense dark green foliage, it has proved to be an excellent hedge plant.   Will produce orange-red berries if a male Chinese holly is planted nearby for pollination.
Canadian Hemlock

(Tsuga Canadensis)

Zones 4 – 8; plant in moist but well drained, humus rich acidic to slightly alkaline soil; full sun to partial shade.Conical, loose, 25’ wide x 40’ tall, good for informal gardensprivacy walls, screens, focal pointsThe loose airy nature of this plant creates a nice relaxed hedge that allows air to circulate through the garden.
Common Boxwood

(Buxus sempervirens)

Zones 6 –8; plant in fertile, well drained soil; prefers partial shade but will tolerate full sun.Round, dense, 15’ wide x 15’ tall, good for formal gardenslow borders, punctuations, containersThis is a great evergreen to use for punctuation at entries or to add structure to perennial borders. Can be clipped into a nice hedges or topiary forms.
Indian Hawthorne

(Rhaphiolepis indica)

Zones 8 – 10; plant in well drained, moderately fertile, moist soils; full sun.Mounding, spreading, 8’ wide x 6’ tall, good for informal gardenslow borders, punctuations, containersDepending on the variety, this plant produces white or pink flowers followed by attractive berries.
Dwarf Alberta Spruce

(Picea glauca ‘Albertiana Conica’)

Zones 2 –7; plant in moist, well draine, neutral to acidic soil; full sun.Conical, 4 – 5’ wide x 6 – 8’ tall, best for formal gardenspunctuations, containersAn excellent conical punctuation. For the best results plant several to create a rhythm or use as an accent in a geometric design
Inkberry ‘Compacta’

(Ilex glabra)

Zones 5 – 9; grow in moist, well drained, humus-rich soil; full sun to partial shade.Round, 4 – 6 wide and tall, good for both formal and informal gardenslow borders, punctuationsDeep green foliage and black berries make this an exceptional backdrop for flowers and colorful foliage.

Protecting Roses in Winter

This is the first year I have grown roses and they have done very well. Remembering how cold it got last year, I was wondering how to best protect my rose bushes throughout the cold winter months. Can you help me?

I have had several questions coming in from various places around the country asking about winter rose care. Most roses can withstand a quick cold snap of temperatures down to 10 degrees F, but it is best to protect them if you expect an extended period of time when temperatures dip under 20 degrees F. The amount of protection your roses need depends on the climate in which you live.

 In the northern areas of the country in Zone 4, which includes states such as South Dakota, northern Maine, Vermont, Northern Iowa, and Minnesota, winter rose care begins after the first hard frost, usually around mid-October and if possible, before the first snowfall.

 The first step in protecting bush-type roses, such as hybrid teas, floribundas, and grandifloras is to loosely tie the canes together to keep them from whipping around in the wind. Then cover the base of the plant with 12 inches of soil. Straw or leaves can be placed over the soil mound for additional insulation.

 If you prefer to use styrofoam rose cones, prune the bushes back so the cone will fit over the plant. Before you cover the bush, mound several inches of soil around the base of the canes then place the cone over the rose. To keep the cone in place, mound soil around the outer base.

 To protect climbing roses, remove the canes from their support, and carefully bend them to the ground. Hold the canes in place with pegs or stakes and cover with several inches of soil. This should be done after the roses go dormant and have been exposed to two or three hard freezes.

 Depending on spring weather conditions, remove protective materials before the buds break open, normally in late March to mid-April.

 In states such as Ohio, Indiana, New York, Kansas, Missouri, Pennsylvania, designated Zone 5 or 6, since the winters are not as severe, you can protect your roses as mentioned above or simply pile protective material around the base of the plants. Another option is to create a chicken wire cage filled with leaves around the base. Your main concern is protecting your roses from extended periods of weather below 20 degrees, winter winds, and fluctuating temperatures.

 For states in Zone 7 and 8 such as Arkansas, Mississippi, Georgia, Alabama, North Carolina, the biggest danger to roses is when temperatures rise and fall causing the ground to freeze and thaw. This often results in frost heaving of the roots from the ground. To prevent that from happening, mound at least 2 to 3 inches of mulch around the base of the rose. To avoid attracting rodents and insects, keep the mulch away from the trunk of the plant.