Germination of Geranium Robustum

Moisture

• Geranium robustum seeds need consistent moisture in order to germinate. They will not do well in soggy soil, however. Keep the soil moist to the touch, but not wet. A simple way to do this is to set the seeding pots in a shallow tray of water and let the soil absorb the water through the hole in the bottom of the pot. When the top of the soil is moist, remove the pots from the tray of water.

Temperature

• Steady, warm temperatures are necessary for geranium robustum seeds to germinate. The ideal soil temperature for germination is 75 degrees Fahrenheit. The seeds will tolerate some temperature changes, but will grow sooner if the temperature is consistent. Place the seeding pots in a location with plenty of sunlight, but out of direct sun. The seeds can overheat and fail to germinate in direct sunlight. On the other hand, they will not germinate if temperatures are too cool. Daytime temperature should be at least 70 degrees.

Growing Medium

• Sterile, well-drained growing medium is ideal for germinating germanium robustum. Commercially prepared seedling pellets or soil is suitable. Another option is to mix together equal parts vermiculite and peat moss. The specific type of planting medium is not as important as good drainage. Standing water in the soil can allow fungus to attack the seedling once it emerges. Sterile potting medium is also important, since viruses can linger in garden soil and attack seedlings before they have a chance to grow and flower.

Time

• Geranium robustum seeds can take anywhere from a few days to several weeks to germinate, depending on conditions. Under ideal conditions, seedlings should begin to emerge five to seven days after planting. Some seeds take much longer, however, so it's important to give them plenty of time. If temperatures are cool or there is not enough moisture, it can take up to four weeks for the geranium seed to germinate.