Tips for Keeping Year-Round Plant Containers
Choose a sturdy container. There are a wide variety of pots and planters available. Be creative! Yard sales and garages can provide all sorts of interesting shapes and sizes. An old bed pan, crocks, whiskey barrels will work and there are some very nice rocks that can be used for planting. Whatever you choose, be sure the container is frost resistant (if not, be prepared to shelter it in the winter or start over) and has adequate drainage. If the container lacks drain holes, get it drilled.
Tip: Before filling the container with soil, line the inside with bubble pack. This will provide some expansion space if the soil freezes and add extra insulation.
Soil mixes – need to be water retentive, light, provide nutrients for the plant and not get compacted. Most potting soil mixes include perlite, or pumice to make the soil porous which keeps air in the soil. After planting fill the container to about 1 inch below the edge. This leaves room for watering and mulching.
Water – Plants in a container dry out faster than in the ground, be sure to water frequently to keep the plant from drying out. Learn to test the soil with your finger, if it’s dry below the surface, its time to water. Water until you see it flowing out the drain holes, this ensures the entire soil ball is moistened.
Note: if water immediately comes out the drain holes, the root ball may be too dry and you may need to soak it to rehydrate it.
Fertilizer – Regular watering leaches out nutrients so container plants generally need regular fertilizing. A balanced slow-release fertilizer will gradually release over time. Be sure to follow label directions and don’t over feed the plant.
Maintenance, pruning and transplanting – Plants will eventually outgrow the container. At that point you can move them to a larger container, remove and divide them – for some plants and start new containers – or you can root prune to manage size. This is best done during the dormant period, early spring, after it has warmed up but before the plant is actively growing.
Remove the plant from the container and using a sharp, clean knife remove some soil from the outside of the root ball. An inch or two on smaller plantings, as much as one-third if it is seriously root bound. Trim up the exposed roots and replant replacing the soil that you have removed with fresh quality potting soil.
Elements of Container Design
Ø Choose plants that you like, it is your garden.
Ø Use different colors, textures and bloom times to create contrast and interest year round.
Ø Foliage lasts longer than flowers, look for plants with interesting and different foliage colors.
Ø A tall plant draws the eye upward, combine with shorter wider plants for balance and finish off with low-growing ground-covers.
Ideas for Year-round Container Plants
Look for dwarf or slow growing varieties of evergreen plants, plants with winter structure and/or interesting foliage. Some of our preferred plants are listed below.
Evergreen trees and shrubs
Alpine fir (Abies lasiocarpa)
Balsam fir, dwarf (Abies balsamea) ‘Nana’
Bamboo (Fargesia, Phyllostachys, Pleioblastus, Pseudosasa, Sasa & others)
Cedar, Weeping Blue Atlas (Cedrus atlantica glauca pendula), Cedrus deodara dwarf
Cryptomeria: ‘Black Dragon’, ‘Knaptonensis’, ‘Little Diamond’, ‘Nana’, ‘Tansu’, & others
Cypress, Hinoki (Chamaecyparis obtusa) Fernspray Gold’, ‘Gracilis’, Lemon Twist,
‘Nana’,‘Nana Gracilis’, Tempelhof’ & many others
Cypress, false or white (Chamaecyparis pisifiera) ‘Sun Gold’, ‘True Blue’, ‘White Pygmy’
Fatshedra and Fatsia japonica
Heavenly bamboo (Nandina domestica)
Korean fir (Abies koreana)
Port Orford Cedar (Chamaecyparis lawsoniana) ‘Barry’s Silver’,‘Ellwood’s Pillar’, & others
Spruce, dwarf (picea) ‘Little Gem’, ‘Papoose’
Strawberry bush/tree (Arbutus unedo, ‘Compacta’, ‘Oktoberfest’)
Umbrella pine (Sciadopitys verticillata)
Black Mondo grass (ophiopogon)
Blue eyed grass (Sysrinchium)
Fountain grass (Pennisetum)
New Zealand Flax (phormium)
Beach Strawberry (fragaria)
Blue & White star creeper (pratia)
Coral Bells (Heuchera)
Corsican Mint (menthe requieni)
Green Carpet (Herniaria glabra)
Hens and Chicks (sempervivum)
Kinnikinnick (arctostaphylos uva-ursi)
Silvermat (raoula australis)
Sun Roses (helianthemum)
Plants with Interesting Winter Structure or Color
Coral Bark Maple (Acer palmatum ‘Beni Kawa’ or ‘Sango Kaku’) Corokia cotoneaster
Contorted filbert (Corylus avellana contorta) Flying dragon hardy orange (poncirus)
Sophora prostrata ‘Little Baby’