What Are The Guidelines For Watering Your Perrenials Before It Is Going To Freeze?

Filed Under: Perennial Plants, Watering, Techniques & Methods · Keywords: Should, Perennial, Plants, Be, Watered, Before, Hard Freeze, Winter · 941 Views
A few years ago I was told my perennials would have a better chance of coming back after winter if I watered them a 1/2 inch to 1 inch a day or two before it's going to freeze. Should this be done every year or can I just do it the first few years? Does this mean perennials that die back in the winter, or one that remain some what green? What about things that reseed themselves? I guess I've just never been clear on the whole thing.

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Answer #2 · Gardenality.com's Answer · I'm in central Georgia. When a deep freeze is forecast I only water the ground around my perennial plants if the soil is dry. As John mentioned, this help because the water forms an ice sheath around the roots of the plant, effectively insulating them at 32 degrees F, which most perennials have no problem tolerating.)

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Answer #1 · Maple Tree's Answer · Hi Melinda-This is a great question. Keeping the soil moist by watering before any expected freezing temperatures helps to insulate the root system. In dry soil roots can easily freeze without this protection. I do this every year making especially sure any potted perennials are moist during freezing temperatures along with wrapping the pots for additional insulation. Applying an inch or two of compost or mulch around the plants also helps to keep moisture in the soil and insulate the plants from any damage from freezing. If you are in an area that has snow much of the winter this also acts as an insulator. Cutting back of perennials and time to do this is many times a matter of ones choice. Some do not like to cut their perennials back in fall if the plant provides some winter interest instead of the bare ground. Some leave their perennials as many will provide food and protection for birds and other wildlife during the winter. If you have some perennials you would like to reseed themselves you wouldn't want to cut off the spent flowers or seed pods. This would not allow any dropping of seeds that will spout in the Spring. Pruning many perennials too early in the fall can force new growth that can be damaged by an early frost. Different perennials may reqire special attention as winter comes and the plants either die back or stop growing. You can always look up a particular plant file that will possibly give you pruning information on that plant or ask a question regarding a particular plants pruning if no information is available. Overall I normally do very little pruning of my perennials before winter. I usually only cut off any dead foliage and some stems that have become leggy looking just to clean up the garden and make it look a little neater during the winter. Leaving the foliage on most perennials helps to protect or insulate the crown of the plants from freezing. I noted a few links to articles that will help you with information on pruning and winterizing your perennial plants. I also noted a nice list of many popular perennials and when to prune them by Sue Kittek who is a freelance garden columnist, writer, and lecturer.



Asters: Allow the foliage to remain to protect the crown
Astilbe: Do not trim; clean up in spring
Bearded iris: Cut back to decrease problems with thrips and fungus.
Cardinal Flower (Lobelia cardinalis): Allow the foliage to remain until spring
Columbine: Remove leaves with evidence of leaf borers and clear the dropped debris.
Chrysanthemums: Allow foliage to remain until spring
Delphinium: Cut back the flower stalks but allow the foliage to remain.
Foamflower (Tiarella): Allow semi-evergreen foliage to remain through winter
Hellebores: Do not cut back. The plants are evergreen and bloom in the late fall through early spring depending on variety.
Heucheras: Do not cut back. The semi-evergreen growth protects the plants from the temperature changes and accompanying heaving common in shallow rooted plants.
Hosta: Although they look dreadful; the foliage offers winter protection and should be allowed to remain until spring
Lady's Mantle (Alchemilla mollis): Allow foliage to remain until spring
Lavender (Lavendula angustifolia, L. intermedia): Allow foliage to remain until spring then cut off any winter dieback
Masterwort (Astrantia major): Cut back any yellowed foliage in early fall but allow new growth to remain
Penstemon (Beardtongue): Cut back the tall foliage and allow the bottom (basal) growth to remain
Peonies, Herbaceous: Cut back to the ground after the foliage dies.
Red Hot Poker (Kniphofia): Very sensitive to cold so allow the foliage to remain
Russian Sage (Perovskia atriplicafolia): Sensitive to the cold: cut back in the spring
Salvias: Cut back foliage to basal growth (the bottom rosette of leaves)
Sedums: Many remain attractive well into winter; clean up in the spring
Yarrow (Achillea): Cut back in early fall but allow any subsequent new growth to remain
Bee Balm (Monarda didyma): Cut back mildewed foliage and discard: allow the seed heads to remain for birds.
Coneflowers (Echinacea purpurea): Although unattractive, they are a source of seed for birds

Please ask if you have any other questions.


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Melinda Marsh

Melinda Marsh · Gardenality Seedling · Zone 6A · -10° to -5° F
Awesome, so incredibly helpful. I have tried to print off information about most of my perennials which i make sure to include when and how to prune, when I've been able to find it.

5 years ago ·
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Maple Tree

Maple Tree · Gardenality Genius · Zone 10A · 30° to 35° F
Melinda, glad I could help. Let me know if you need any information on any plants you can't find information on.

5 years ago ·
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