Continuous Containers With Cool Season Flowers

Who says you have to wait and plant your containers in May after a final frost? I have plants in my containers all year long and start my season in early to mid March after pulling out Christmas greens, using a long list of early spring flowers (see below) that can tolerate and flourish in chilly weather. And when the summer flowers are looking tired in my pots in early Fall, I pull them out and refresh with some more cool temps plants that bloom in the autumn. And then the Winter branches and berries go in. And the cycle goes on. That way, I have continuous containers with seasonal color all year long using this easy method.

Go to Porch Pots to see my Winter containers that will be transitioned to Spring ones.

There are so many flowers, both annual and perennial, that you can use before the lingering cold subsides that I make up at least a half dozen containers with different combinations  to cheer me up after a long cold winter. Having stored my winter coat and scarves and gotten out lightweight fleeces, I am starved for color and ready to plant and enliven the outdoors after a cold and gray winter.

If you plant your containers in mid-March, around St. Patrick’s Day, the plants will be in place for 6-8 weeks before you need to replace and freshen with heat loving ones.

Step By Step Pointers 

Here are some pointers on making those early spring ventures as successful as possible. First, acclimate your transplants to the cold as any plants you buy will have been grown in greenhouse conditions where they aren’t exposed to harsh outdoor weather.  This is called ‘hardening off’.

Using a cold frame is an easy way to accomplish this. Alternatively, you can place your plants in an unheated garage or porch area for at least a week. You don’t want your expensive new plants to react to the sudden change of temperatures by succumbing to cold winds and freezing temperatures. Flowers, rather than foliage, are the most susceptible to cold.

Last year, I had a cold snap in April where the nighttime temps went down to about 29 degrees. I placed a frost protection plant cover over my containers and they sailed through without any problems. Breathable and light, it you can tent it over the container to conserve heat. Another method of shielding your containers from cold and wind is to place them in a sheltered position, next to a wall or house. I really like using these covers as they have 3-layers of protection and are easy to put on and remove with one zip.

 

Transitioning Your Containers

Transitioning your containers from one season to the next doesn’t mean you need to rip everything out and start at ground zero. Some plants will look good all year long and can act as base plants that you can leave in most of the year like Ivy, Creeping Jenny, Yucca, Coral Bells, and a variety of other perennials, like spring blooming Scabiosa or Pin-Cushion plant, Sedum, and Nepeta. I love using Evergold Carex, an evergreen Japanese Sedge, that looks good any season and drapes over the edge.

And don’t forget the vegetables and herbs! Parsley, Swiss Chard, Ruby Red lettuce, Bull’s Blood beets, Dusty Miller, and Cabbages are all great cold hardy foliage colors to add different hues and shades to the more exciting flowers.

Plants Need Nutrition

Be sure to add appropriate amounts of fertilizer and compost when adding new plants, as the nutrients can quickly be exhausted with all that plant musical chairs. I use pre-measured fertilizer PotShots by Osmocote that break down that give a quick boost as well as loose Osmocote for a steady slow release.

Design Principles

There are principles to follow in designing just like any other time of the year when you plant your containers:

Use Contrasting Textures and Colors

Height Variation

Focal Points

Seasonal Accents

Well-Draining Soil

 

Hardy Annuals

Hardy annual plants are the most cold-tolerant kind of annual plants. They can handle a slight freeze and colder temps than marigolds and zinnias and are good choices for early fall and early spring plantings. But be careful – A sustained hard freeze though will do them in! And plants that have had time to adjust to increasingly cold weather will be hardier than those that suddenly encounter it. So, don’t forget to harden off your plants.

Here is my list of cold tolerant annuals that I use regularly:

• Pansies & Violas
• Calendula
• Foxglove
• Sweet Alyssum
• Larkspur
• Lettuce
• Bloody Dock (Rumex)
• Sweet William
• Dusty Miller
• Snapdragon
• Nemesia
• Swiss Chard
• Parsley
• Dill
• Sage
• Anemones
• Ranunculus
• Poppies
• Cerinthe or Honeywort
• Chinese Forget Me Not
• Cornflower
• Bells of Ireland
• Petunias
• Sweet Peas
• Lobelia
• Potted bulbs of all kinds, tulips, daffs, grape hyacinths are just a few

This list is by no means inclusive of all annuals that thrive in cool temperatures, but it offers a good selection of colorful and easy-to-grow flowers.