How to Winterize Lilac Shrubs

Beloved for his or her excellent spring exhibits that function fairly flowers with an intoxicating perfume, lilacs deal with chilly winters higher than many perennial flowering shrubs.

Little is required to help them via chilly temperatures and lots of species and cultivars, together with frequent lilacs, Syringa vulgaris, require chilly climate to set flower buds.

A little bit prep work earlier than frigid temperatures arrive will help stop points like harm or breakage from gnawing pests or heavy, moist snow.

And there are particular circumstances – like a late freeze – when proactive measures will help your lilacs keep away from falling sufferer to bud kill.

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Dwarf lilac varieties in containers might also want some extra safety or a sheltered web site if freezing temperatures and harsh situations are frequent in your area.

Even the cultivars bred for heat climates have their very own distinctive must survive winter and emerge in spring able to flower and flourish.

If you happen to’re questioning methods to maintain your showy shrubs wholesome till subsequent spring, let’s leap into methods to winterize lilac shrubs!

Right here’s a peek at what’s forward:

Why Shield Chilly Hardy Shrubs?

Frequent lilacs have wonderful chilly hardiness and are appropriate for overwintering in USDA Hardiness Zones 3 to 7, though some cultivars are appropriate for Zones 8 and 9.

Some cultivars of S. hyacinthiflora are hardy right down to Zone 2, however many dwarf varieties are hardy solely to Zone 5.

The time period “chilly hardiness” describes how low temperatures must drop earlier than a plant suffers harm.

The usual reference for North American gardens is the USDA Plant Hardiness Zone Map, with every Zone given a quantity based mostly on the “common annual excessive minimal winter temperature.”

For Zone 3, that ranges from -40 to -30°F – so lilacs don’t want quite a lot of assist to deal with the chilly!

Nonetheless, there are uncommon occurrences when the shrubs may want a frost blanket to guard rising buds from a late freeze. And so they’ll respect a layer of mulch to maintain the roots protected from heaving in freeze and thaw cycles.

Additionally, some preventative pruning can cut back the danger of limbs breaking beneath the burden of heavy snows or freezing rain.

Container grown lilacs are extra inclined to break from chilly climate and normally want a little bit of consideration earlier than frosty temps arrive.

And don’t overlook in regards to the critters – herbivores like deer, rabbits, and voles can chew away the bark and tender ideas in the event that they’re hungry sufficient.

Additionally, the varieties bred for gentle Zones 8 and 9, with low chill hour necessities could not need to take care of snow and excessive chilly, however in areas with dry winters, they should be watered frequently to stop them from drying out.

Earlier than we get into every of those situations, a number of upkeep fundamentals are useful.

Earlier than the bottom freezes, clear up the beds or containers the place your lilacs are rising, eradicating particles and litter – backyard particles gives a great location for pests to overwinter.

Our information to getting ready the backyard for winter discusses this and different ideas for conserving crops protected.

Use a small rake to take away summer time mulch, lifeless leaves, and any undesirable decaying plant matter.

If autumn rains have been inadequate, water your timber deeply earlier than freezing temperatures set in – they’ll be a lot stronger and in a position to face up to harsh climate when they’re well-hydrated.

Container Crops

Potted lilac crops can require extra safety throughout chilly climate.

It is because the soil in containers and pots can freeze strong, inflicting harm to the roots.

Shield the Root Zone

To guard container-grown lilacs from freezing chilly, add a four-inch layer of mulch over prime of the foundation zone, utilizing porous supplies that don’t entice water reminiscent of bark, conifer needles, or straw.

And relying on how low your temperatures drop, wrapping the pots in bubble wrap or an outdated blanket can add an additional layer of insulation to maintain the foundation zone from freezing.

Transfer to Shelter

Containers will also be moved right into a sheltered spot to guard them from harsh winds and publicity to the weather.

Websites that usually keep a few levels hotter than open areas embody in opposition to the outside wall of a heated home, beneath evergreens, or tucked right into a nook by a fence.

Bury Containers

In case your winters are very chilly, an alternative choice is to bury your potted lilac. To do that, the pot must be fabricated from a cloth that may deal with freezing temperatures, reminiscent of resin or plastic.

Pure supplies like terra cotta or glazed ceramics are normally too delicate to bury within the backyard and are unlikely to resist freezing temperatures.

For more information on robust, weather-resistant supplies, try our information to the perfect supplies for containers, pots, and planters.

To bury container crops, select a sheltered spot within the backyard, and dig a gap a number of inches wider than the pot.

If the container is giant, it will not be potential to bury it completely, however attempt to get not less than half of it beneath the soil.

Fill the hole between the soil and pot with a thick mound of bark mulch, evergreen boughs, leaves, or straw, then mound the mulch supplies up the pot’s sides and over the soil line, protecting the lilac’s crown as nicely – intention for an insulating layer of six to eight inches.

When the worst of the chilly climate has handed, pull the insulation again from the crown.

As the nice and cozy temperatures of spring strategy, take away the remaining coverings, return your containers to their rising web site, and water deeply if wanted.

Unheated Storage

A closing possibility is to maneuver your containers into an unheated constructing after the primary laborious frost, reminiscent of a storage, greenhouse, or shed. Test the soil’s moisture month-to-month and water as wanted.

Keep in mind that almost all lilac varieties require a variety of chill hours to set flower buds, so they need to by no means be introduced indoors to a heated location.

Chill hours is the time a plant spends beneath 45°F – most hybrids of S. vulgaris require round 2,000 chill hours whereas the newer cultivars with low chill necessities want solely about 500 hours.

Pots overwintered in a storage or shed must be moved again outdoors a number of weeks earlier than the final common frost date in your area.

When you’ve got quite a lot of containers to maneuver annually, contemplate selecting up a sturdy plant caddy to ease your workload.

In-Floor Care

Though they’re well-equipped to deal with chilly climate, lilacs can undergo harm from desiccating winds, freeze and thaw cycles that heave roots, harm from heavy snows and freezing rain, or a bud-killing late freeze.

Forestall Desiccation

The best solution to stop desiccation is to develop your lilacs in a location shielded from prevailing winds.

Being deciduous, the leaves aren’t broken from drying winds however tender ideas and branches can die off.

The shrubs must be well-hydrated earlier than the bottom freezes as a result of drought-stressed crops are extra prone to chilly harm, significantly newly planted specimens.

To assist them fight the drying results of freezing winds, water lilac shrubs deeply earlier than the bottom freezes – after the primary mild frost is nice timing.

Shield from Freeze and Thaw Cycles

To assist stop the roots from heaving when uncovered to freeze/thaw cycles, cowl the foundation zone with three to 6 inches of mulch – thicker is healthier in very chilly temperatures.

Unfold the mulch out to the drip line and make sure to cowl the shrub’s crown. 

Use supplies which are porous and don’t entice water, reminiscent of bark mulch, conifer needles, evergreen boughs, pebbles, or straw.

Prune Broken Limbs

Though pruning isn’t wanted for younger lilac crops, it may possibly assist to stop harm to well-established timber and shrubs.

Breakage to the branches of huge, mature timber can typically happen from the burden of heavy, moist snow or freezing rain, inflicting limbs to break down and break free from bigger stems.

If heavy, moist snow and freezing rains are a daily prevalence, you’ll be able to enhance the weight-bearing capability of your shrubs by frequently pruning the guidelines of lengthy, lanky stems each two to 4 years.

Pruning ought to solely be completed in late spring to early summer time, shortly after flowering has completed – to prune at every other time ends in bud loss the next 12 months.

To maintain your shrubs tidy and cut back the possibility of breakage from weighted limbs, use clear, sharp shears to move again development of department ideas by as a lot as one-third, reducing the stems at a forty five° angle simply above a wholesome leaf node.

Our information to rising lilacs has extra particulars about methods to prune your shrubs for vibrant floral shows.

Late Freeze

It typically occurs throughout late winter or early spring {that a} chilly snap with freezing temperatures can harm or kill off rising flower buds – a serious disappointment when it occurs.

As lilacs are all in regards to the flowers, just a little further work to guard the dear blooms is well worth the effort!

To maintain the buds wholesome and keep away from harm from a late freeze, earlier than the chilly temperatures arrive, cowl the shrubs with sheets of burlap, frost safety cloth or baggage, or an outdated sheet, secured in place with plant clips.

Keep away from utilizing sheets of polyurethane. If the plastic rests on the buds, it may possibly conduct and switch the chilly temperatures, inflicting harm.

Take away protecting covers as quickly because the hazard or freezing temperatures passes.

Harvest-Guard Plant Safety Bag

Frost safety baggage fabricated from spun polyester can be found at Burpee.

Critter Guards

Bugs aren’t normally an issue in freezing temperatures, however herbivores could come visiting seeking meals.

Mice, rabbits, and voles usually gnaw at trunks and stems to succeed in the layer of tender, moist tissue beneath the bark, and deer are more likely to chew on tender ideas.

If hungry herbivores are a difficulty, you might have to erect a bodily barrier to guard crops like deer netting or {hardware} material.

Deer netting is fabricated from sturdy polypropylene and is simple to arrange round a tree’s perimeter with stakes or rebar, forming a fence to maintain deer at bay.

Wire mesh is available in a roll and is simple to bend and manipulate to form, making it a sensible choice to wrap across the trunks of timber to thwart the likes of mice, rabbits, and voles from damaging the bark.

{Hardware} Material

Rolls of {hardware} material with a one-half inch mesh can be found at Tractor Provide.

Objects like smelly deer repellent are additionally an possibility, which you’ll learn up on in our information to deer-proofing your yard.

Cultivars with Low Chill Necessities

With cultivars bred for areas with low chill necessities, crops drying out from a scarcity of water is the most typical drawback skilled in winter.

Though your temperatures may keep heat and gentle, these crops nonetheless go dormant and cease actively rising – however they shouldn’t be allowed to dry out utterly.

In case your winters are sometimes dry or rainfall is insufficient, water your lilacs deeply on a month-to-month foundation.

Chilly Climate Champs

Frequent lilacs are chilly climate champs, and readily deal with freezing temperatures, snow, and normal chilly climate nastiness!

And whereas they require little help to outlive frigid temperatures, you are able to do a number of issues to assist them emerge unscathed from the cruel situations of winter.

If autumn’s rainfall has been mild, give them an extended, deep drink earlier than the bottom freezes – well-hydrated crops are higher outfitted to deal with harsh climate than these which are drought-stressed.

Give them a pleasant, thick layer of mulch to guard the roots from heaving, which might happen throughout freeze and thaw cycles. And maintain them pruned to cut back the possibility of breakage beneath heavy snows.

Add a frost blanket if a late freeze threatens flower buds, and don’t overlook to guard them from hungry critters. If furry foragers are an issue, put up a deer fence or use {hardware} material to save lots of your shrubs.

Just a few protecting steps taken earlier than the dangerous climate arrives is value it while you see your lilacs loaded with aromatic flowers come spring!

Any specific winter issues your shrubs need assistance with? Inform us about it within the feedback part beneath.

And for extra lilac know-how, add these guides to your studying record subsequent:

Photographs by Lorna Kring © Ask the Consultants, LLC. ALL RIGHTS RESERVED. See our TOS for extra particulars. Product photographs through Burpee and Tractor Provide. Uncredited photographs: Shutterstock.