Overwintering Salvias in Pots: A Complete Guide

Salvias (ornamental sages) are a must in the summer garden. They come in a huge variety of shapes and colors, and the nectar-filled flowers attract bees, butterflies, and other pollinators. Many of them bloom from midsummer until the first frosts, and they flower for months on end. Many of them also have fragrant leaves. The name ‘salvia’ derives from the Latin salveo, meaning ‘I heal’ or ‘I save’. Salvia officinalis is a culinary herb that the Romans and ancient Greeks used as a medicine. It is in the large genus Salvia.

Salvias look good in almost all planting schemes. They look great in a mixed or herbaceous border and are great for planting under roses because they flower just as the roses are dying back. They are also said to keep mildew and black spot away. Some also look at home in a tropical or exotic planting scheme, alongside dahlias, bananas and cannas. Many salvias are ideal for a coastal garden and are often a key plant in a dry garden. That’s right, they do great in pots and make long-lasting patio displays. Take a look at this pot of salvia, euphorbia, and pelargonium.

The spikes of tube-shaped, lip-shaped flowers come in a huge range of colors, from soft pink and white to deep purple, magenta, scarlet, and electric blue. The size and appearance of salvias can vary greatly, and they can be divided into four main types:

Salvias that grow every year, like Salvia farinacea, Salvia horminum, and Salvia splendens, are used as colorful summer bedding and then thrown away at the end of the season.

Salvias that grow back every year, like Salvia nemorosa and Salvia x sylvestris, are hardy and tough. Cut these back after their first flowers fade in July for another display later in the summer.

Some salvias, like Salvia greggii and Salvia elegans, are tender perennials that come back every year. However, they are not completely hardy and may need to be protected during the winter.

Shrubby salvias such as Salvia x jamensis and Salvia microphylla are sub-shrubs with woody stems. Most are hardy and some are evergreen in mild winters, but they may also need protection in winter.

Salvias are stunning plants that add vibrant color to gardens with their spiky blooms While many salvias are hardy perennials, some types are not cold tolerant Overwintering non-hardy salvias in pots can be challenging, but is possible with careful preparation. Follow this guide to increase your chances of successfully overwintering potted salvias.

Salvia Hardiness

Hardy perennial salvias like Color Spires® and Profusion® series are cold tolerant to zone 3 and require no special overwintering.
Rockin’® and Unplugged® series are generally considered annuals, only hardy to zone 9

A few varieties like Rockin’ Playin’ the Blues® and Unplugged So BlueTM are exceptions being hardy into zones 7 or 8.

Overwintering Location

Overwintering potted plants outdoors is very difficult, especially in cold climates. A sheltered location like a garage or shed is better.

Unheated garages may reach zone 7 temperatures, allowing borderline hardy salvias (to zone 8) to survive if properly prepped.
Avoid locations that will freeze solid for months. Extended freezing will likely kill roots.

Best Practices for Overwintering Pots

Follow these tips to improve success overwintering containerized salvias:

Use large pots: Choose thick, insulating containers like ceramic or plastic to prevent roots from freezing. Small, thin pots will not protect roots from cold.
Trim back: Cut plants back to 4-8 inches tall in fall so no foliage is wasted over winter. Plants will reshoot in spring.

Water minimally: Keep soil slightly moist but avoid excessive moisture, which can cause root rot in cool weather.
Provide insulation: Place pots on insulation like foam board and cover with burlap or straw to retain warmth in root zone.
Monitor conditions: Check pots occasionally for moisture and signs of new growth. Keep an eye on temperatures.

Spring Care

As temperatures warm in spring, situate pots back outdoors. Wait until after the chance of frost passes.
Hold off on fertilizing until new growth resumes. Then use a balanced, slow-release fertilizer to avoid tender new growth.
Prune back any dead stems and shape plants as needed. Healthy shoots will soon emerge.

Transition plants to full sun over a week or two to harden off before summer.

Tips by Salvia Type

Rockin’ Playin’ the Blues (Zone 7 hardy)

Overwinter in zone 8-9 garage or shed to improve success.
Use a ceramic or thick plastic pot for insulation.
Keep drier in winter to avoid root rot.

Unplugged So Blue (Zone 8 hardy)

Overwinter in zone 9-10 garage or shed.

Choose a large, insulating pot and provide supplemental insulation.
Monitor soil moisture closely and don’t overwater.

Rockin’ Fuchsia or Rockin’ Deep Purple (Zone 9 hardy)

Overwinter in zone 10-11 shed or garage only.
Select the largest possible ceramic or plastic pot for root insulation.

Water sparingly over winter months.

What to Expect

Be prepared for some dieback and leaf drop even if the root system survives the winter. As long as new shoots appear in spring, the plant should recover with care. Some tips:

Dead stems can be pruned any time to improve appearance.
Water sparingly until new growth emerges to prevent rot.
Add fertilizer once plants are actively growing to fuel regrowth.

Move back into full sun gradually over a week or two.

Even if your overwintered salvia doesn’t make it, you can always purchase new plants in spring. But following these tips will greatly improve your chances of success overwintering container salvias through cold months.

Troubleshooting Overwintered Pots

Limited regrowth in spring

Root damage from cold. Try improved insulation next winter.

Underwatering during winter caused roots to desiccate. Keep slightly moist.

New shoots but then sudden collapse

Root rot from excessive winter moisture. Water minimally while dormant.
Lack of light/nutrition causing weak growth. Move to sun, fertilize.

Leggy regrowth in spring

Insufficient light after overwintering. Gradually introduce to full sun.

Leaf drop after relocating outdoors

Shock from sudden change in light/temp. Harden off gradually over a week.

Failure to bloom

Too much fertilizer early on caused lush, weak growth that won’t flower. Avoid fertilizing until established.

FAQ

Can I overwinter salvias in outdoor containers?

Overwintering pots outdoors is challenging. Even cold hardy varieties may not survive winter in containers. Move them into a protected location.

What if my garage gets below freezing?

Temperatures dipping just below freezing overnight are often tolerated if pots are properly insulated. But extended sub-freezing temps can damage roots.

Can I transplant salvias into the ground in fall?

Yes, transplanting salvias from containers into the ground in early fall can improve their winter hardiness. Mulch well once ground is frozen.

Should I prune back plants before overwintering?

Yes, cut back any leggy growth to 4-8 inches so energy isn’t wasted on leaves that will be shed anyway. New growth appears in spring.

Overwintering salvias like Rockin’ and Unplugged in pots is possible but tricky. Use large containers, shelter from cold, trim plants back, and monitor soil moisture. Be patient in spring for regrowth. With preparation and care, you can save tender salvias through winter!

Where to buy salvias online

Salvia ‘Amistad’ is a half-hardy perennial. It is long-flowering and particularly floriferous, with rich-purple flowers. It’s often still blooming when the first frosts arrive, and is a good food source for late-season pollinators. Height x Spread: 1. 2m x 50cm.

From July to early September, Salvia nemorosa ‘Caradonna’, also known as balkan clary, blooms in spires of electric blue flowers. Deadhead to prolong flowering or simply cut back hard in July for a second flush. H x S: 50cm x 50cm.

Protecting salvia plants in winter

To ensure that you can enjoy salvias from year to year, take cuttings in late summer.

In mild areas, cover tender salvias with 10 cm of well-rotted manure or garden compost to keep them safe from frost. In colder areas, lift them as you would dahlias and overwinter them in pots indoors.

Salvias shouldn’t be cut back in the fall; wait until late spring. The leaves will protect them from frost in the winter. Trim the plant’s top growth back to just above the new shoots coming up at the base in late spring.