Monday, September 27, 2010

Fall Garden Maintenance: Pruning and Dividing Ornamental Grasses & Perennials

Maiden Grass 'Yaku Jima'
Ornamental grasses can add much interest to the winter landscape and can be enjoyed all winter long.  Here's a helpful fall tip for pruning and dividing your ornamental grasses such as 'Miscanthus sinensis' Maiden Grass or Dwarf Fountain Grass 'Hameln'. Winter cold can do harm to the root system of grasses.  It is best to cut your grasses back in late March to early April in order to protect the roots and ensure the health of your plants.  If your ornamental grasses become a bit unruly by the end of the fall cut them back to only one half the height of the plant and leave the rest for early spring. Another trick is to wrap a bungee cord about halfway up around the center and let the grasses drape over keeping them upright and in place. In late March or early April cut your ornamental grasses to approximately 4-6 inches above the ground so that new growth can emerge. 

Sedum & Fountain Grass 'Hameln'
Since new growth occurs on the outside edges of the root crown, the center of ornamental grasses often start to die out as the grass matures.   If your grasses are starting to hollow in the center before winter it may be time to divide them. Early Fall and early Spring are the best times for this procedure. This must be done when the grasses are actively growing so the earlier in fall the better.  If you should decide to divide your larger grasses an axe or hacksaw may come in handy.  Use a sharp spade to completely dig around the perimeter of the grass and lift up out of the ground.   This may take some muscle and may require a couple of extra hands!  Now depending on the size of the grass you can use either an axe, hand saw or a gas powered saw to divide it into cleanly cut pieces for planting.  Dig a large enough hole to allow the roots to spread and plant the new clumps of grass at exactly the same height as they were planted before. Remove any loose pieces, add mulch for protection from cold and water in thoroughly
Stella D Oro Daylily
When your daylilies are at the end of their bloom in August and the foliage is starting to yellow cut them back half way to the ground. They will rejuvenate giving you lush green foliage and even more blooms throughout September and into October. (Works best with Stella D Oro Daylily).  Dividing daylilies is also best in the fall for the health of your plants.  Simply dig deeply around the perimeter of the plant and gently lift the entire clump out of the ground.  Use a sharp spade to divide the plant into parts and plant each section into a hole twice the size of the root ball.  Be sure to get at least three or more strong shoots and a good root ball around the plant.  Cut the foliage back halfway and back fill with soil around the plant.  Then add mulch around the base to protect the roots and water thoroughly.   Keep the plant well watered until the roots become established.  At the end of the season once the fronds have turned completely brown remove all foliage to the ground to prevent fungal disease over the winter.  Other plants that benefit from fall division are salvia, iris, peony, hosta, goldenrod, monardia (beebalm), nepeta, coreopsis and sedum. 

Nepeta 'mussinii'
It is also good practice to prune back spent perennials to within a few inches above the ground in the fall and to surround the area with a layer of mulch.  This procedure prevents possible infection from fungal disease and helps to insulate the plants during winter. Perennials that benefit most from fall pruning  include hosta, daylily, nepeta, salvia, coreopsis, gaillardia, phlox, monardia, veronica, platycodon and yarrow. Liriope, Heuchera (coral bells), astilbe, liatris, lavender, perovskia (russian sage) and lupine are all cold sensitive and should be left to be pruned in early spring.

Author: Lee@A Guide To Northeastern Gardening Copyright 2010. All Rights Reserved.

Thursday, September 2, 2010

The Fall Garden

Dwarf Fountain Grass (right) . Spirea (left) , Hosta (center)
The Fall garden can be beautiful in its own way. Seen here is a combination of grasses, spirea and hosta in all its’ fall glory. As the days become shorter and temperatures lower an array of oranges, yellows, reds and tans emerge in the garden. When I design I like to use plantings that show off their beauty in the later summer and fall as well as in the warmer temperatures. Just as other colors fade grasses just start to get their abundant plumes and spirea go into a color burst of oranges and yellows.

Sedum 'Brilliant'
As I gaze into my garden an array of deep pink now steals the show. This autumn favorite is Sedum ‘Brilliant’. Sedum is just going into bloom now at the end of summer and it holds its' color well into autumn. Sedum comes in a variety of sizes and colors including Sedum ‘Autumn Joy’ (18-24” orange blooms), Sedum ‘Brilliant’ (18 “ rose blooms), Sedum ‘Rose Glow ‘ (8-12” pink blooms) and Sedum ‘Fulda Glow’ (4” rose-red blooms). Other fall favorites include: Callicarpa (Beauty Bush) with its deep purple berries, Perovskia (Russian Sage), Rudbeckia (Black Eyed Susan), Agastache (Hyssop) and Hamamelis (Witch Hazel). Just as the other elements in the garden start their exit these beauties begin their vibrant display. 
As far as maintenance is concerned it is good practice to prune back spent perennials to a few inches above the ground to prevent fungal diseases and to surround the area with a layer of mulch that will insulate the plants during winter. It is best to completely cut back perennials such as hosta, daylily, nepeta, salvia, coreopsis, and gallardia to prevent disease. Grasses on the other hand should be kept throughout the winter in order to protect the roots and cut back to about 4-6 inches off the ground in late March. If your grasses are a bit unruly at the end of the summer season you can take off a portion of the top but it is recommended that the majority of the cutting back be done after the harsh winter. Plants such as heuchera (coral bells) continue to show color throughout the winter and are prone to frost heaving so they are best cleaned up in the spring. Astilbe, Liatris, Lavender, Russian Sage and especially Lupine are sensitive to cold and are better being pruned back in early spring after the cold temperatures have ceased. Black Eyed Susan and Coneflowers even though not that attractive in winter serve an excellent food source for birds and can be cut back in early spring.

Rudbeckia (Black Eyed Susan)

Happy Gardening!
The garden season does not have to end in August. Add some of these plants to your gardening list and add some fall interest to your landscaping.

Author:Lee@A Guide To Northeastern Gardening Copyright 2010. All Rights Reserved