Fall Clean-up Tip: GRASSES: Cutting back ornamental grasses in fall can be harmful to them since freezing temperatures and cold snow lying on the crown on the plant can “hollow” them out. Grasses should be cut back in late March/early April once the threat of frost is gone and before new growth appears. If you want to tidy up your ornamental grasses, cut them back half-way in fall and leave the remainder of cutting back to spring. Leaving the grass during the wintertime also provides interest to the garden while preventing damage to its center.
The same technique should be used for maintaining Liriope (Lillyturf). Prolonged freezing temperatures can do damage to the crown of the plant, so it is best to leave the pruning until early spring when first signs of new growth appear.
Other ornamental grasses such as Japanese Forest Grass (Hakonechloa macra ‘Aureola’) die back in winter but do look attractive in the landscape The same principles apply and pruning is best when performed in late winter/early spring.
Have the temperatures been rising and are you yearning to go out into the garden? Spring is here and it is a time to start planning and prepping the garden for a successful start to the planting season. There are some recommended maintenance tips for getting your garden underway. Here is a list of common gardening tasks to be performed in late winter/early spring. (I recently posted this article on my other blog A Guide to Northeastern Gardening, but felt it was also fitting for here.)
True or False? Any dead material remaining from last year should be removed from your garden now. True. It is best practice to remove dead material from the garden in fall to prevent possible pests and disease in your garden. If you have left annuals or perhaps perennials for winter interest, now is the time to tend to them, along with any weeds that might have survived the winter. Pull out any dead remaining annuals and prune perennials back to the ground to encourage new growth. If cold temperatures are still to be expected, push mulch up around the crown of the plants to protect them from temperature fluctuations.
True or False? New mulching should be applied now before the ground thaws.False. Mulch acts as an insulator and applying mulch before thawing would actually inhibit warming as temperatures rise. Allow the soil to warm, then apply two to four inches of natural pine mulch. When applying, keep mulch several inches away from tree and shrub trunks to prevent oxygen loss and rotting. Mulch benefits plants by reducing water evaporation, preventing weeds, adding organic matter to the soil and also acts as a buffer, preventing drastic changes in soil temperatures.
True or False? Nitrogen based lawn fertilizer can only be applied after April 1st. True. According to the EPA, the prohibition on application of fertilizer between December 1st and April 1st applies to products that contain nitrogen (N), phosphorus (P), or potassium (K). If a product does not contain any of these nutrients, it could be applied during the winter months without violating this law. Explanation: If the ground is frozen, there is a greater danger of runoff and possible contamination of groundwater. Fertilizers applied when the ground is thawed and porous are absorbed and utilized by plant material and go through a natural filtration process before reaching the aquifer system. Please note that there are a variety of organic, natural fertilizers on the market that are more environmentally friendly. Success rate depends on brand and application.
True or False? Spring flowering trees and shrubs should be pruned in late winter/early spring. False. General rule of thumb is to prune flowering plants AFTER they flower. Early spring flowering trees and shrubs including rhododendron, azalea, forthysia, magnolia, plum, Eastern Redbud and cherry form their buds from the season before and should be not be pruned until after flowering. Pruning them now will remove flower buds that have already formed, resulting in a loss of blooms.
True or False? Summer blooming shrubs such as Spirea and Buddleia should be pruned in spring. True. Mid and late summer flowering shrubs such as Spirea and Buddleia (butterfly bush) prefer a spring pruning to promote fullness and blooms. Prune Spirea slightly for shaping. If the plant is overgrown to the point it is unsightly, it can be pruned more drastically to rejuvenate it now in spring. Buddleia benefits from an early spring pruning and should be pruned all the way back in late winter/early spring to promote fuller plants and better blooms in late summer. This practice is best performed once you see signs of life on your plants.
True or False? The best time to prune evergreens is in early spring. True. Evergreens can be pruned anytime when there is no threat of extreme temperature changes that would cause undue stress; however, the best time is either in early spring before they push out new growth, or afterwards once new candles form. When pruning evergreens that form candles, such as white pine, it is best to cut candles in half to keep the plant more compact.
True or False? Liriope and grasses should be cut back and divided now in spring. True. Liriope and ornamental grasses can be cold sensitive. Exposing the crown of the plant could be the reason for snow and cold damage. It is best to leave liriope and grasses alone in fall and to prune them back in early spring to allow for new growth. Spring is also the time to divide and move other perennials that have become overgrown. It is recommended that most perennials be divided every four years for best bloom. Dig up and divide with a sharp clean spade just as new growth appears, replant and add a sprinkle of slow release plant food in with the soil to help root promotion. Water in thoroughly.
True or False? Knock Out Roses should be pruned back in early spring. True. Wait until your roses are sprouting new shoots and showing some signs of life. Then, prune off dead wood or overgrown branches back about one third the size of the plant to promote strong growth and blooms. Be careful to watch while pruning so that you achieve a nice rounded shape for your plant. Early spring is also a good time to apply an organic slow release rose fertilizer mixed in with the soil at the base of the plant to ensure a successful start to the growing season. I would also recommend a regular watering schedule from the base of the plant, since roses do not fair well with constant water on their foliage.
True or False? Summer blooming bulbs should be planted in late spring. True. While spring blooming bulbs such as crocus, hyacinths, tulips and daffodils are planted in fall, late summer blooming bulbs such as Dahlia, Canna and Gladiolus are planted in spring. Amend the soil with compost or manure to insure them a good start and plant in a well-drained area to prevent rotting. Generally, bulbs are planted at a depth of three times their diameter, and specific instructions are usually supplied on the packaging. Once planted, water your bulbs thoroughly and be sure they get watered regularly. Applying bone meal will give your bulbs energy during the growing season, but do not mix in too closely to the roots.
Will the unpredictable weather we have been having across most of the U.S. and other areas harm my garden? I have been getting asked this question quite a bit over the past couple of years. Generally, plants are pretty resilient. Buds that are forming on the trees early are sparked by the warmer temperatures in daytime but slowed down by the colder nighttime temperatures, which tends to balance out their progress. If there is severe cold for a prolonged period of time, buds could freeze and get damaged, but the tree produces enough buds to still have a bloom. More sensitive plants like old fashioned hydrangea ‘Nikko Blue’ that bloom on old wood are more susceptible to cold and time will tell. If there is die back on your plant, prune out the dead wood and apply a dose of a high phosphorus fertilizer. It could help to boost larger blooms from any undamaged buds. Hydrangea varieties that bloom on new wood, such as ‘Endless Summer’ and ‘Pee Gee’ should winter alright.
Some of my evergreens are a bronze color. Should I be concerned?Winter bronzing is normal on evergreens near the end of winter while temperatures are cold. Once the temperatures rise and new growth is stimulated, the foliage will turn back to a more vibrant green. Broken or dead branches are different in that they are completely dried out and brown. Those branches should be pruned off the tree in late winter/early springtime to prevent any further damage. Any falling or divided tree leads can be arbor tied to secure them and encourage upright growth. Split branches can also be arbor tied together, and if caught in time the cambium growing layer of the tree can mend. In the photograph above, the center upright Western Arborvitae are displaying bronzing and there are no signs of broken branches. As you can see the trees are healthy.
Have you heard about my new book,Landscape Design Combinations? My first bookA Guide to Northeastern Gardening covers recommended plants for zones 3-9 with topics including butterfly gardening, deer resistant plants, shade gardening, perennials, trees and shrubs, evergreens, general maintenance tips and more.
Landscape Design Combinations is a continuation of the previous publication, with greater emphasis on design, including numerous numbered and labeled photographs of successful landscape plans. Topics include elements of landscape design, designing for the seasons, how to build a natural stone patio or walkway, simple container combinations and garden styles throughout the centuries.
Both A Guide to Northeastern Gardening and Landscape Design Combinations were written to provide you with the tools needed to help you to create a successful garden. Click on the links below for more information and previews. I hope to inspire you!
Here is a review of some basic gardening tips and chores as winter approaches.
Watering During Fall & Winter: Plants, especially evergreens require moisture throughout the colder months. Moisture is often provided by occasional rain or snow cover (which also provides insulation for the roots of your plants). It is a common misbelief that is unnecessary to water in winter; however, once the ground freezes it is difficult for water to percolate down to the roots. Dehydration can result from the lack of water. Deciduous trees go dormant but evergreens remain somewhat active and require some moisture for survival. Water as much as possible before the ground freezes, especially if you have new plantings and if there is a period of drought water when the ground thaws.
Anti-Desiccant Spray: Certain broad leaf evergreens such as cherry laurel, skip laurel, mountain laurel, boxwood, euonymus, holly, rhododendron, Japanese skimmia, leucothoe and aucuba can be subject to severe winter burn due to water loss from the leaves by transpiration. When the daytime temperatures start falling below 50 degrees it is time to apply an anti-desiccant spray such as wiltpruf to protect these plants. Apply when the temperatures are above freezing and there is no threat of rain or frost within 24 hours. (This tip applies to areas going into their winter season-temperatures dropping below freezing: 0 degrees Celsius or 32 degrees Fahrenheit.) If there is a prolonged thaw in mid-winter it may be time to re-apply anti-desiccant spray to your broad leaf evergreens, especially if there are more prolonged freezing temperatures on the way.
Pruning Ornamental Grasses: Ornamental grasses can add much interest to the winter landscape and should not be cut all the way back for winter. It is best to cut your grasses back in late March to early April in order to protect the roots from frost which could do damage. If your grasses become unsightly by the end of the fall simply prune back the plumes and leave the rest for early spring. Another trick is to wrap a bungee cord about half way up around the center and let the grasses drape over keeping them upright and in place.
Weeding: A little preventive weeding in fall can give your garden a good start to spring. Some weeds tend to multiply in the cooler temperatures and if not tended to can be a nuisance in the warmer months. On a milder day when temperatures are above freezing weeds can be removed easily and should be disposed to prevent spores/seeds from spreading elsewhere. Also decaying foliage from perennials and around plants should be removed to as a preventive to fungal infection.
Frost Heaving: In sustained below freezing temperatures followed by thaw the soil expands upwards from the ground causing plants to push upwards exposing the crown. This is known as frost heaving. Certain plants such as Heuchera (Coral Bells) and Liriope are especially prone to this type of damage. As a preventive measure apply a mulch finishing to your garden beds. If frost heaving does occur slightly tap the soil back down and brush the mulch back around the exposed top of the plant to protect it from the cold.
Ice Damage to Branches: If snow piles up on your evergreens do not immediately shake the branches for it could cause breakage and damage. Try to carefully brush the snow away removing any excess weight. If the tree or shrub is covered with ice permit nature to take its course and allow the ice to melt naturally. If your trees or shrubs do suffer any damage from winter storms it is recommended to remove any broken limbs to avoid stress and disease to the plant. This can be done when the weather allows.
Garden Tool Care: Before storing your garden tools for winter clean them thoroughly with water and gently remove any built up soil to prevent corrosion. It is recommended to oil any moving parts on your pruners and loppers and spray any wooden handles on tools such as shovels with linseed oil in order to keep them from drying and cracking. It is also a good time to re-sharpen your shears, loppers and shovels so your tools will be all ready to go when spring arrives.
In Summary: Some simple preparation can go a long way especially in areas where winters are harsh. I have found these techniques to be very worthwhile and productive over the years and they should do the same for you! As always…happy gardening!
March is here and there is much to do in the garden before spring arrives. Here is a list of some basic late winter garden maintenance tips to get your plants off to a good start.
(1) Clean up garden beds. Remove dead leaves and debris.
(2) Start pulling weeds while the ground is soft and before seed heads start to form.
(3) Plant summer flowering bulbs such as Gladiola, Canna, Iris, Lillium and Dahlia.
(4) Divide and move hostas before their leaves start to appear.
(5) Now is also the time to divide and move other perennials that have become overgrown. It is recommended that most perennials be divided every four years for best bloom. Dig up and divide just as new growth appears and water in thoroughly.
(6) Prune back liriope and ornamental grasses to allow room for new growth.
(7) Prune Buddleia (Butterfly Bush). It is at this time of year when Buddleia can be hard-pruned (cut all the way back) in order to encourage new growth and better blooms.
(8) Prune Knock Out Roses to eliminate leggy branches and encourage fullness. Root feed when new growth appears.
(9) Re-edge garden beds leaving a 2-3″ border between the garden and lawn.
(10) Apply a fresh layer of mulch to planting beds. Mulch should be approximately 2-4 inches in thickness. Remove any excess build up around plants before adding new and be sure that there is no mulch piled up around tree trunks.
(11) Prune dormant fruit and ornamental trees. Remove any diseased or broken branches to ensure health of the tree. It is also time to prune/shape your Spirea and Barberry while still dormant.
(12) Spray dormant deciduous trees and shrubs with horticultural oil to prevent early insect damage. Apply when there is no danger of frost within 24 hours of applying. Deep root feed ornamental trees, broad-leaved and needled evergreens.
Once the March garden chores are done it is time to await spring blooms and enjoy a landscape that is off to a healthy start. More maintenance tips will be on the way in April!
Ornamental Grasses: Winter cold and snow can harm the center of ornamental grasses causing them to “hollow out”. To protect ornamental grasses such as ‘Miscanthus sinensis’ Maiden Grass or Dwarf Fountain Grass ‘Hameln’ avoid the temptation to cut them all the way back in Fall. Instead keep the roots well protected and wait until late March to early April to cut them back fully. If your grasses become a bit unruly by the end of Fall (November-December zone 7) then just cut back the plumes and leave the rest for early spring. Another trick is to wrap a bungee cord about half way up around the center and let the grasses drape over keeping them upright and in place. Ornamental grasses can add much interest to the winter landscape and be enjoyed all winter long. For more information visit: Fall-Garden-Maintenance-Pruning-&-Dividing-Ornamental-Grasses-and-Perennials