Preparing the Garden for Winter     OH 3

Leonard Perry, Extension Professor

Plant and Divide Peonies: Peonies are best planted in late August or early September. Established clumps need
dividing perhaps every 15 to 20 years. Each division should have 3 to 5 "eyes" (the reddish buds on the tubers). Plant
with the eyes no more than 2 inches below the soil surface, or plants may not bloom.

Remove Summer Mulch from Stem Base of Woody Plants: If summer mulches were used to prevent weed growth
and moisture loss, keep them away from the base of tree and shrub stems. Check the stems in mid-August and
remove the mulch so it doesn't prevent the development of winter hardiness. Consequent cold winter temperatures
may injure plants at the stem base.

Plant Spring Bulbs: Tulips, daffodils, hyacinths, crocus, and other spring bulbs should be planted early in the fall to
allow time before frost for good root growth. Late planting may result in limited root growth and poor flower
development in the spring. Mulches applied over the bulbs keep soil temperatures warmer and may help late-planted
bulbs to develop roots.

Plant Trees Shrubs, and Evergreens: Fall planting of evergreens is best done between mid-August and early
October to encourage root growth before winter. Deciduous trees and shrubs (those that lose their leaves in winter)
are best fall-planted after mid-October. Container-grown plants can be planted anytime during late summer and early
fall.

Store Tender Corms, Bulbs, and Roots: Gladioli, tuberoses, dahlias and other tender underground plant parts
should be dug after frost has killed the tops. Remove soil, let surface dry and store at cool, above-freezing
temperatures for the winter. Dusting them with an all-purpose garden pesticide containing an insecticide and fungicide
may prevent pest damage. Place these plants in dry vermiculite, peat, or sawdust for winter.

Clean Up Garden Debris: Old leaves and stems can harbor overwintering insects and disease spores. Destroy any
obviously diseased or infested materials. Other material can be composted, but this does not always assure the
destruction of pests it may harbor.

Water Trees and Shrubs Thoroughly Before Freeze-Up: This is especially important for evergreens, which
continue to lose moisture through their foliage. Plants in moist, but not water-logged soils tend to survive the winter
best.

Prepare Soil in New Gardens: Fall plowing is better than spring plowing for most garden soils, unless winter soil
erosion is a problem. Sod skimmed from the top of new beds can be added to the compost pile.

Protect Herbaceous Perennials: Perennials may be killed by heaving due to alternate freezing and thawing of the
soil, or by exposure to extreme low temperatures. Snow cover makes the best winter protection. At sites having snow
cover all winter, few perennials may need further protection. At sites not having snow cover all winter, weed seed-free
hay or straw, wood shavings, dry sawdust, or loose organic mulches may provide good protection. Leaves (other than
oak or beech) tend to mat down and may injure plants by excluding air. Do not apply mulch until after mid-November.
Plants need cool, fall temperatures to develop some winter hardiness. Some perennials with green leaves such as
strawberries, periwinkle (or myrtle), and pachysandra may benefit from winter mulching, but are easily injured by
mulches that pack down.

Mulch Around New Plantings: Mulches can be applied to fall-planted trees, shrubs, evergreens, and vines in early
November to keep the soil temperature higher than unmulched soil. Roots of woody plants have been shown to grow
late into fall when soil temperatures are above freezing.

Protect Tree Trunks Against Bark Splitting: Sunscald is a form of winter injury that affects the bark of many
young trees. Bark splits as a result of rapid thawing of frozen bark by following early morning winter sun. In
mid-autumn, wrap the trunks of young trees with commercial tree wrap paper or burlap to protect against this type of
injury.

Protect Evergreens Against Winter Burn: The foliage of many broad-leaved and needle-type evergreens may be
injured when exposed to winter winds or afternoon sun. Protection may be provided by the application of
anti-desiccant sprays applied in late autumn, or the use of shades and screens to cut down wind and to shade plants
from sun. Burlap or saran screening wrapped around stakes driven into the ground around plants is usually better than
wrapping the plants with burlap. Polyethylene sheeting should never be used for winter protection.

Protect Shrubs and Evergreens From Falling Snow and Ice: Foundation plants and those near driveways, walks,
or streets are subject to crushing from snow or ice. Tepee-shaped wooden frames may be necessary to prevent injury.

Protect Tender Plants Against Cold: Some plants used in the Vermont landscape cannot survive the cold
temperatures that may occur here in mid-winter. Wrapping these plants with straw and burlap or paper may modify
cold temperatures a few degrees on cold nights, but does not provide adequate protection in most cases. Where
practical, use a frame to hold the mulch, dry vermiculite, peat, sawdust, or other granular materials.

Garden roses can be protected with mounded soil or the above-mentioned materials to a depth of 12 to 18 inches.
Apply protection in mid- to late November. See OH 4, "Winter Protection of Hybrid Roses."

Ground limestone can be added to the soil in the fall, if necessary, to correct soil acidity. Organic matter, such as
compost or manure, can also be worked into the soil in the fall to improve soil structure.

Appreciation is expressed to Susan Littlefield for assistance in preparing this publication. (Appreciation is expressed to Susan Littlefield for assistance in preparing this publication.)

Last reviewed 2003