By Andrew Bunting
PHS Vice President, Public Horticulture
For a relaxing and socially distanced activity, I turn to my garden for tranquility. And, serendipitously, the timing is ideal for me to do spring plantings and gardening. One of my favorite projects this time of year is to plant my container gardens.
All container gardening is basically the same, and it is quite simple and easy to create a beautifully planted container -- you'll need a container, drainage, soil, water, and of course plants! To get started you will need to have a container to hold the soil. This can be a traditional pot like a terracotta pot, a plastic container, or a glazed container. It just simply needs to be able to hold soil. I have also used a lot of containers over the years that were not intended for plantings, but which I have retrofitted to use as one. At a flea market one year I found a bunch of colorful sap buckets used for harvesting sap to make maple syrup. I have also used old galvanized containers. Anything will work! It is totally subjective and up to your own tastes.
In addition to being able to hold soil, a good container must be able to drain. If there is no drainage outlet, then the soil will become overly saturated and cause the roots of your plants to rot and ultimately die. Most pots you purchase for plants will already have a hole. If it is a pot you are retrofitting (like a galvanized pot), you may need to add holes by drilling or punching them in the bottom.
Avoid common gardening wives’ tales about containers to save yourself time! It is often recommended to add crushed gravel or a broken old terracotta pot at the bottom of your container to increase drainage. I have probably planted 3,000 planters in my lifetime, and I have never added anything to the bottom of the pot to increase drainage. Sometimes “feet” are recommended between the bottom of the container and the patio or wherever the containers will sit to increase drainage ability. Unless the bottom of your pot is perfectly flat or your surface is completely flat, the water will find its way out -- so in short, don’t waste your time or money.
For my containers, I like a potting soil that includes some pine bark in it for drainage. Other people like to use Perlite, a naturally occurring mineral, which will also add drainage. You can also use compost if you have a compost pile or access to leaf compost.
Lastly, water your pots and keep an eye on watering! I always water the pots after the initial planting and then only water on an “as need basis." For all plantings, I prefer they dry out a little between waterings.
While this video highlights plants for early spring temperatures, the same principles can be used for summer, fall or winter plantings. The plants I chose will look good from mid-March to mid-May. Many different plants can take these same spring temperatures such as pansies, wall flowers, ornamental kale, and rainbow chard -- many good for early color in your garden.
For this demonstration, I used three basic design principles that I use with all my containers. Kathy Pufahl owned a great nursery on Long Island that specialized in unusual annuals called Beds and Borders, and she taught many container workshops. Her simple design terms have stuck with me. You need to have a good central focal point in your container or the “thriller.” In the case of this container, I used an upright rosemary, Rosmarinus officinalis. I know that the rosemary will withstand the cool temperatures and be a great central feature. Then any type of bushy side plants can be filled in around the “thriller.” In this case, I used two silver foliaged lavenders, Lavandula ‘Goodwin Creek Grey’. Kathy referred to these as the “fillers.” And lastly, you need something that can be your edging plant or in some cases spill over the edge of the pot, so I used the purple foliage of lettuce called ‘Merlot’ and a creeping thyme, Thymus vulgaris, as the “spillers.” If you use the “thriller, filler and spiller” approach, you will never go wrong.