A. Containers

Any kind of tub, barrel, pot, or urn can be used as long as its size is proportional to the mature size of the plants; 6-12 inch pots can be used for bulbs, perennials, and annuals but 18-24 inch, or larger,containers should be selected for trees and shrubs. It should be deep enough to allow sufficient root growth. To prevent cracking in cold climates, select containers made of plastic, fiberglass, featherock, or asbestos cement. It is also possible to make light, frost proof containers out of one part Portland Cement (not ready mixed), one and one-half parts sphagnum peat and one and one-half parts vermiculite or perlite.

B. Soil

Many packaged potting soils such as Metro Mix, Pro-Mix, or the Fafard Mixes are suitable for container plants. A basic potting mix can be made by mixing 2 parts humus (peat moss, compost, rotted sawdust, etc.) and 1 part sandy loam or coarse river sand. For all but acid-loving plants, add 1 tablespoon of dolomitic lime for each total gallon of soil mix.

C. Maintenance

1. Watering: Watering is easy if a 1/2 - 1 inch space has been left between the top of the container and the soil level. More watering is necessary because of the high proportion of root to soil area but will depend on the exposure to sun and wind, type, and number of plants and porosity of the container. In the heat of summer, many pot plants will require daily watering. When growth is active and plants are flowering, they need more water than at other times.

2. Drainage: To avoid overwatering, one large hole or several smaller ones punctured in the bottom of the container is helpful. To avoid stoppage, cover the holes with large pieces of broken flower pot, gravel, or packing peanuts. A layer of sphagnum moss over this will prevent the soil from washing out. Slightly raise any container resting on a solid surface with cleats or set on bricks or a block of wood.

3. Light: Proper light can be provided by placing the plants in the optimum exposure preferred by the plants. Sun and shade are no less important to container grown plants than others.

4. Fertilizing: Because container gardens are in active growth and flowering, they need a richer soil than either house or garden plants. This does not call for increasing the quantity of fertilizer per application, but for feeding on a more frequent schedule. Use a water soluble fertilizer (like Miracle-Gro or Peters) according to label directions throughout the summer.

5. Root Pruning: Vigorous plants will eventually fill their con- tainers with a solid ball of roots. Instead of supplying larger containers, it is possible to cut off some of the outer roots. The proportion of roots that can be safely removed is something less than one-quarter of the whole depending on the size and maturity of the plant. At the same time, prune woody plants at the top so the balance between top and roots is maintained. Root prune herbaceous plants at the start of a new growing season.

6. Pruning Shrubs and Trees: Relatively little pruning is required because the limited area restrains both the root and top growth.

7. Supports for Vines: a. Permanent planters - Place the planter near the wall or trellis.

b. Mobile planters - Build light trellises which can be firmly anchored in the soil or fastened to the side of the container.

SUGGESTED PLANTS FOR CONTAINERS

Annuals:

Many annuals make excellent pot plants. With their shallow roots, they are well adapted to container gardening techniques. To keep them in good condition, they need regular care. Pinch to encourage branching. Remove all faded blossoms for continued flowering and water regularly.

Begonia               Petunia                Impatiens

Verbena                Marigold              Zinnia

Bulbs and Tubers:

Achimenes           Crocus              Narcissus

Caladium             Hyacinths          Tuberous Begonia

Canna                   Lilies                  Tulips

Calla

Perennials:

Arenaria              Gaillardia                Rudbeckia

Asters                  Heuchera                 Salvia

Bergenia               Hostas                    Sedum

Calluna                   Iris                           Sempervivum

Campanula          Liatris                      Strawberry

Cyclamen               Monarda                 Vinca Minor

Dianthus                  Fuchsia                   Yucca

Ferns                       Daylily                       Primula

Nepeta                    Gerbera

Shrubs:

Abelia grandiflora                Cytisus                    Azalea                          Pieris

Ilex                                           Boxwood                 Rose                          Nandina

Cotoneaster                           Taxus                     Gardenia                    Spiraea `Shibori'

Trees:

Acer palmatum                      Prunus                     Ficus                          Styrax

Sophora japonica                 Malus                         Pyrus                       Caragana `Pendula'

Vines (sun or partial shade):

Akebia                                   Lonicera                    Clematis                       Mandevilla

Humulus                                Gloriosa Lily            Thunbergia                   Morning Glory

(little or no sun):

Hedera

Trachelospermum