Container Recipe for Geranium Plants

Geranium plants (Pelargonium spp.) Insert bright color, texture and scent to container plantings when among the six big geranium groups is included in the grass. When thinking about geraniums, the zonal geranium (P. x hortorum) most often comes to mind. But other groups include ivy-leaved, angel, regal or Martha Washington, scented and distinctive. Trailing species, such as ivy-leaved geraniums (P. peltatum), add dimension to window boxes and hanging baskets. Scented species offer a sensual encounter beyond visual appeal. All geranium species are half-hardy and require protection when temperatures fall below 36 degrees Fahrenheit. A container recipe for successfully expanding geranium plants includes provision of full sun, a cool root zone, good drainage and a slightly acidic potting mix.

Base Ingredients

Container recipes for growing geraniums are either soil-based or soilless. Soil-based recipes contain one-fourth to one-third garden dirt. Recipes using one-fourth dirt also utilize one-fourth peat moss, coir — coconut hulls — or other similar stuff. Both peat moss and coir decompose gradually, supplying nutrients for healthy plant growth. Peat moss has a pH of approximately 4.0, requiring the addition of stone to raise the potting mix to a pH level between 5.5 and 6.5. Soilless mixes use peat moss, coir or a similar material as the base ingredient.


Geranium plants are subject to mould (Botrytis cinerea), black leg (Fusarium sp.) And black stem rot (Pythium splendens) when the potting medium remains wet and dries out gradually. Excellent drainage is essential for a successful potting mixture recipe, which ought to contain one-fourth to one-third non-organic substance to increase drainage. Fine Gardening specifies perlite as a high-fired volcanic rock that lightens dirt and creates pockets for air and water flow. Coarse river mud also allows for drainage and aeration while supplying a press upon which roots may cling. Playground sand increases friability, or looseness, of a potting mixture. Selection from one of these materials depends upon accessibility and personal option.

Organic Matter

Organic matter offers slow-release nutrients. Compost, composted manure, worm castings, leaf mould and composted pine bark are acceptable as one-third to one-fourth of the quantity of a geranium potting mix. Composted products are not all equal, as organic matter and composting methods vary widely. Just well-composted manure should be used at a container recipe for geraniums.


When potting recipe ingredients are thoroughly blended and slightly moist, a soil test to determine pH level is taken, following soil test maker’s directions. Ground stone is added based on soil test recommendations to increase the pH to 6.5, the optimal level. A small number of charcoal pellets may be added to each gallon of potting mix to reduce odors related to organic matter decomposition. N.C. State University Cooperative Extension advocates the inclusion of 1/2 teaspoon of lawn fertilizer and one teaspoon of dolomitic limestone per 8-inch container of mixture or according to soil test results. Commonly used garden fertilizers are formulas such as 5-10-5 or 6-12-12.

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