If you have perennials in your container garden or plan to overwinter some plants in a warmer climate, winterizing a container garden is important. It helps protect your plants from the colder temperatures, wind, and frost most zones will get at least a few times during the winter months. If you’re wondering how to prepare your container garden for winter, I have some tips and suggestions below!
Keep in mind that containers are more susceptible to cold than in-ground gardens because the roots are closer to the air and can more easily freeze.
Winterizing your container garden helps prevent root damage and protects them from drying out in dry winter months. It also helps prevent the soil from freezing and thawing repeatedly, which can cause the soil to become compacted and limit the plants’ ability to absorb water and nutrients.
Taking the steps to winterize can also help prevent the spread of pests and diseases. Dead plant material can harbor pests and diseases, so removing dead stems and leaves before winter can help prevent the spread of these problems in the spring.
Overall, winterizing your container garden is an essential step to help ensure the survival of your plants during the winter months and to give them a healthy start in spring.
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How to prepare your container garden for winter
Clean your containers
Among gardening experts, you’ll find mixed opinions about how to clean pots and containers from your garden. Some advocate for a thorough scrub-and-bleach routine. Others say soap and water are sufficient. Those with a more rustic approach suggest brushing off the old dirt and plant matter and calling it a day.
Personally, I’m usually a mix of a gentle soapy rinse and just brushing them clean. I personally don’t think bleach is necessary, and some blogs that insist on bleach call for very strong concentrations of it, more than you would use to sanitize any other surface.
Here’s what I suggest:
- Scrape and/or brush away dirt, dried plant matter, and other debris. Use scouring pads or stiff utility brushes, or for stubborn mineral deposits, try steel wool.
- Rinse off with a hose on the sprayer setting. If they still aren’t clean to your liking, rinse with a diluted dish soap mixture (a few drops in half a gallon of water) and then rinse again with plain water until clean.
- Set pots out in the sun to dry.
- Stack upside down in a clean, dry area until ready to use.
I do think it’s fine to stop there! But if you want to be extra thorough (or had bad luck with previous plants in those pots), try a vinegar rinse. It’s more gentle and less toxic than bleach.
Here’s how you do it:
- Soak pots in a vinegar solution (1 part vinegar to 5 parts water) for 30 minutes.
- Rinse well with dish detergent diluted in water (a few drops in half a gallon or so), then again with water only.
- Set all pots out in the sun to dry.
- Stack upside down in a clean, dry area until ready to use.
Remove dead plant material and prune your winter plants
If you have perennials in your container garden, or you live in a warm zone where you can overwinter more plants, you’ll want to prepare them for the cooler winter season and anticipate slower growth.
Remove any dead leaves, stems, or flowers from your plants. This will help prevent the spread of diseases and pests and encourage fresh growth when it starts to warm up again.
Likewise, you’ll want to prune any overgrown or damaged branches on your plants. This will help them conserve energy and focus on new growth in the spring.
Mulch containers in winter
If you have some perennials or other overwintering plant friends, add a layer of mulch to your containers. This will help insulate the soil, help retain moisture, and protect your plants’ roots from colder temperatures.
Make sure to apply the mulch evenly and at least 2-3 inches deep. Avoid piling the mulch up against the plant’s stem, as this can cause the stem to rot.
Be sure to remove the mulch in the spring to allow the soil to warm up.
Protect container plants in winter
If possible, move your containers to a protected area, such as near a garage or shed — but make sure they still get some sunlight. This will help protect them from the wind and cold.
A patio greenhouse is a great way to overwinter plants, if you have space for one!
Watering plants in winter
If you have frost-hardy perennials, water them thoroughly before the first freeze. This will help them stay hydrated and strong as the temperatures drop.
After that, most plants need a deep drink every 2-4 weeks, as long as temperatures are above freezing during the day. Check growing instructions for your specific plants.
How to cover winter potted plants
If your area gets a lot of frost and hard freezes, consider covering your plants with blankets or burlap plant covers during cold snaps to protect them from freezing.
Be sure to remove the coverings during the day to allow sunlight to reach your plants. Also be sure not to let the covers touch the plants, in case they get soaked with snow, ice, or rain. Wet material can freeze against your plants and damage them.
Fertilizing potted plants in winter
Fertilizing outdoor potted plants in winter isn’t always necessary, as colder temperatures and reduced sunlight send many plants into a dormant phase where they don’t need as many nutrients.
That said, there are a few steps gardening experts recommend to help ensure your container plants receive the nutrients they do need during the winter months:
- Choose a slow-release, all-purpose fertilizer, rather than a quick-release fertilizer that can cause rapid growth and damage to the plant in cold temperatures. Jobe’s Organics All-Purpose fertilizer is one of my favorites! It works well with herbs and vegetables.
- Reduce the frequency of fertilizing during the winter months, as the plants’ growth rate will be slower. A good rule of thumb is to fertilize once every 4-6 weeks instead of every two.
- Apply fertilizer in moderation, as too much can burn the plant’s roots and damage the plant. Be sure to dilute water-soluble fertilizer, following package instructions.
- Water the plant thoroughly before and after fertilizing, as this will help it absorb the nutrients more effectively. Avoid overwatering, as too much water can have the opposite effect and drain nutrients out of the soil.
- Monitor the plant’s growth and health throughout the winter. If the plant appears to be struggling, it may need less or more fertilizer than you are currently providing. Also consider moisture and sun levels when assessing potential causes of decline.
(Want to learn more about fertilizer and how it works? Check out my Fertilizer 101 post!)
Check on your plants
Check on your plants periodically throughout the winter. If the soil is dry, water them. If they appear to be struggling, take steps to protect them.
Plan for spring!
- Check out my Container Garden Planner post for step-by-step instructions on how to plan ahead.
- My 26-page printable Container Garden Planner will help you plan and track every step of the way!