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How Do You Overwinter Strawberries?

How Do You Overwinter Strawberries?

“What do you do with strawberry plants in the winter?” Question from Jacklyn or Portland, Oregon

Answer: In mild areas like yours, strawberries (Fragaria spp., USDA Zones 4-9) are very hardy, so no special overwintering measures need to be taken. You can, however, clean them up and thin clumps that are over 3 years of age to encourage strong fruiting. Central plants that are three or more years old start to produce less and less fruit. If you replace the main plants with one of the plant’s newer offshoots, you will get more strawberries the following year.

Start by weeding around your strawberry plants. You can also protect them with light straw or leaf mulch around the base of the plants. If you have older strawberries that need to be thinned and replaced, remove the central plant, and plant in its place one of the larger offshoots that have rooted. Fertilize your new strawberry plants with an all-purpose slow-release fertilizer to encourage good rooting and growth through fall and again late winter. Feed once more in early to mid-spring.

From there, I encourage you to watch our video about everything that you need to know about growing strawberries.

Happy gardening,

Jessie Keith

Black Gold Horticulturist

How Do You Safely Overwinter Rose Containers?

How Do You Safely Overwinter Rose Containers?

“I have roses in containers. What is the best way to overwinter them in zone 6b? I have a Winchester Cathedral, a Young Lycidas, and a Jubilee Celebration. There is another one that looks similar to the Young Lycidas, but the flowers and scent are a bit different. It is also a David Austin rose, but it was unmarked when I got it from a nursery a couple of years ago.” – Question from Kristen of Stephens City, Virginia

Answer: Start by identifying the hardiness zones for each rose, if you can. In this instance, Winchester Cathedral, Young Lycidas, and Jubilee Celebration are all hardy to USDA Hardiness Zones 5-11. The rule of thumb is that potted shrubs must be at least two hardiness zones hardier than yours to reliably survive winter in an exposed container. Because you live in a Zone 6 area, and your roses are not hardy to Zone 4, you will need to protect your potted roses from hard freezes.

How to Protect Potted Roses from Hard Freezes

There are several methods. Just remember, that regardless of where you place your rose, the pot cannot become completely dry. If placed in a garage or under a patio or eave, supplemental water will be needed to keep the plants alive. Too much moisture can also be detrimental, so I recommend twice-monthly watering through winter, to be safe. Here are four reliable methods of protection.

  1. Protect the pots and roses where they stand. Mound Black Gold Garden Compost Blend around the base of the rose, wrap the top in burlap (tops can be tied or lightly pruned to make this process easier). Mound mulch or moistened chopped leaves along the base of the pot as insulation.
  2. Move the pots of a protected area against the side of the house away from wind. If you live in a very windy area, use this outdoor method. Mound compost around the base of the rose, and wrap the top in burlap. Mound mulch or moistened chopped leaves along the base of the pot to act as insulation.
  3. Move the pots to a protected garage. Place your pots in a safe zone in the garage. Slightly dry roses overwinter better than overwatered ones, so maintain light watering as detailed above.
  4. Move the pots to a protected basement or root cellar that remains cold enough to keep them dormant. Freezing or near-freezing temperatures are necessary.

In the spring, remove any protective coverings and organic layers. It is especially important to move the compost away from the base of the rose and into the garden.

I hope that these tips help!

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Overwintering Outdoor Ceramic Containers

With 150+ potted containers throughout my garden, it is important that I overwinter them well. Living on the relatively mild western slope of Oregon’s Willamette Valley, our winters do not compare with those in colder parts of the country, but we do get freezing temperatures. Almost every winter, we will have some nights when the temperatures dip into the low 20’s and sometimes into the high teens. While we also have our fair share of rain during the winter months, we often get a few days of snow and ice, which can wreak havoc on containers.

Protecting Wintering Containers

This snow-covered Italian Terracotta flower pot will likely weather through the winter.

Plants in containers are exposed to the elements more than those in the ground. Pots do not offer roots as much insulation or protection, but each is different in its protection and durability, whether glazed ceramic, concrete, plastic, Terracotta, or stone.  (In this article, we will cover ceramic pots, which are what I use.) Just like the hot summer sun can quickly dry soil in a container, especially with Terracotta pots, cold temperatures, and winter wind can freeze the soil. The ice expands, and as it does, it often has enough force to crack certain pots, especially if the soil is moist.

The question is, what ceramic containers endure winter cold without cracking? In our climate, it would be very unusual for a container not to have soil wet from the winter rain and then potentially freeze. So, having the right container is an important necessity.

Over the years, I have learned through trial and error what pots work. The conclusions that I have reached are not scientific but based on my own experience in dealing with different types of pottery from different places. Some behave poorly outdoors and are better reserved for indoor plantings.

Pots for Indoor Use

Mexican pottery is fantastically pretty but cracks easily outdoors in freezing winters.

First, bear in mind that some manufacturers add elements to their clay to make pots more winter hardy, and some don’t. Thickness and firing temperature can also help prevent cracking. Generally, I have found that Terracotta-based Mexican pottery, glazed or unglazed, will not survive a cold winter without cracking. Likewise, most pottery from China is variable, but the thin pots tend to crack. Some of the most beautiful pottery that I have seen is from Thailand, but it tends to be thin-walled and is poor for outdoor planting.

Thin-walled ceramic pots tend to crack while thicker-walled pots don’t.

We do have some pots from Thailand in our garden, though. These tend to have unique designs and colors and create much interest from visitors. We use Thai pots as pieces of garden art with nothing planted in them. There are holes in the bottom for the rain to drain through, so there is no concern about cracking.

If you choose to grow summer annuals in pots that are not reliably frost-proof, take out the soil when you remove the annuals. Or, if your containers are mobile, move them into a garage to protect them.

Pots for Outdoor Use

Thick-walled, high-fired Vietnamese pottery survives the winter very well for me.

Containers from Italy seem to go through our winters just fine, but those that consistently weather through without cracking are from Vietnam. In our area, the Vietnamese pots sold in local garden centers are thick-walled, highly glazed and fired, very heavy, and frost proof. I have some pots from Vietnam on our deck that we have had for 15 plus years, and they have never cracked. These pots are exposed to winter winds, rain, freezing; they have no protection from the elements.

Thick, high-fired Italian pottery also withstands winter cracking better.

Another important factor when a purchasing pot is getting the right pot for the right location. Check the selection of winter-hardy pots at your local garden center for colors, sizes, and styles with good thickness, high fire, and thick glaze. I have found that the right colorful containers scattered throughout the garden are permanent additions that also serve as garden art.

Microclimates play a role, too. Try to protect your outdoor pots through winter by placing them below overhangs or patios close to the house. Not only can this further help protect them from cracking, it helps the shrubs or perennials they hold.

How Do I Overwinter My Fuchsia Baskets?

“How do I overwinter my fuchsia baskets?” Sherry from Camas, Washington

Answer: What a great question! Large, happy fuchsias are expensive, so it pays to overwinter them. You have two overwintering options:

Bring Your Fuchsia Indoors

Clean your fuchsia before bringing them indoors (click here to read how), and maintain them as house plants through winter. Place your baskets in a location with bright, filtered sunlight. Water the plants when the soil begins to dry in the upper 2 inches. If your home is cool, they will likely need less frequent watering. They are best fed with a slow-release fertilizer.

Fuchsias grow best in rooms with high humidity, so refrain from growing them near heating vents that will quickly dry their foliage and soil. Prune back any dead or dying branches, and keep a watch out for pests, such as white flies and spider mites. Treat them with insecticidal soap if they develop any pests (click here to learn more about house plant pest control).

Induce Dormancy or Semi-Dormancy

Most hybrid fuchsias are not cold hardy, aside from the reasonably hardy hummingbird fuchsia (Fuchsia magellanica), which survives to USDA Hardiness Zones 7-9. More tender varieties will go semi-dormant if maintained under temperatures between 36 and 45 degrees Fahrenheit–never lower. This is the most trouble-free way to store them through winter. Cut back the dead foliage in spring, and give them good care before taking them outdoors again. Spring is also the best time to upgrade them into new pots with fresh potting mix, such as Black Gold All Purpose Potting Mix.

Happy gardening!

Jessie Keith

Black Gold Horticulturist