Geraniums bloom in a burst of deep reds, scarlet, pinks, white, purple or salmon with flowers lasting throughout the gardening season. Geraniums are used in beautiful flower beds or in containers, planter boxes, or hanging baskets on porches, patios or balconies. Plant in a location with 5 to 6 hours of full sun each day after the last Spring frost. During the hottest Summer months, a location providing afternoon shade will keep your geraniums blooming all season. Geraniums are known to be a drought tolerant/water wise container and bedding plant.
Remember as plants receive sunlight for growing, the demand for water and fertilizer is established. The more sunlight received, the more water and fertilizer needed. The demand for water and fertilizer will decrease with less sunlight and overcast weather. (Fertilizing should start when the plant begins its active growth in the spring). Fertilize lightly or not at all in cold weather months.
Many plants, if left to their own devices tend to become ill shaped and unattractive. This can be avoided by pinching back new growth where indicated or pruning if heavier trimming is necessary. Potted plants should be rotated one quarter turn clock-wise every few days to insure a more symmetrical plant.
Many container grown geraniums are killed because of improper watering. Establish a wet-saturated to moist-dry watering cycle. Make sure not to water blindly. It is not sufficient to just give the plant a squirt with the hose or to pour in 2-3 cups of water. The water register is the are between the surface of the soil and the top of the container. Fill the water register until water runs out the bottom of the container. The plant needs to be thoroughly watered so the soil is wet all the way to the center of the root ball.
Check the plant's need for watering by looking at the soil; better yet, scratch the soil surface with your finger or use a moisture meter. If the soil is barely moist or dry below the surface layer, the plant needs watering. Anything wetter than barely moist should probably wait. I say probably because so much depends on the weather. If we are in the midst of a heat wave, or if the plant will be exposed to dry winds, it may need watering more often to maintain it through the day. Container plants should be watered in the morning hours if possible.
If your plants are long stemmed or with leaves only at the tips, and the shape of your plant is off then they should be pruned. The best time to prune geraniums is November through late January.
POTTING MIXES AND SOILS
While the type of soil is important, it is not too critical a problem because Pelargoniums will grow in most any kind of soil, providing there is good drainage. They will not tolerate wet feet. A too soggy soil will become sour, resulting in a sick plant.
A good mix should have excellent drainage, good aeration and good water retention capability. A good mix must be light enough to permit watering frequently on hot weather without danger of oxygen deficiency and heavy enough to retain enough moisture for the plant, and should be light enough to allow for drying out during cloudy days without danger of salt build-up. Suggested commercial mixes: Jungle Growth, Supersoil or any well balanced soil.
ADJUSTING YOUR GARDEN SOIL ACCORDINGLY
IF YOUR SOIL IS:
Heavy, clay soil - Mix in equal part to one-third, your soil, peat moss and perlite
Medium, sand, clay-Mix two parts of your soil to one each of peat moss and perlite
Sandy soil - Mix in three parts of your soil to one part peat moss and perlite.
P.H. Balance: 7.0 neutral below 7.0 is acid and above 7.0 is alkaline. Geraniums need a P.H. of 6.0 to 7.5. A high or low P.H. can damage your plants.
Several edema conditions arise under certain greenhouse conditions. These conditions are caused by any combination which inhibits the normal transpiration from the foliage. Mainly, it occurs when the roots send up more moisture from the warm soil than the cooler foliage can transpire. This causes an over-turgid condition and the leaf-cells burst. Areas of damaged cells heal as corky brown areas, showing mainly on the underside of the leaf. This often resembles severe scarring by mites. Although, in some cases, it is quite possible for Botrytis to enter the damaged tissue, Edema affects the plant only so fare as the corky cells are concerned. Plants even in sereve cases of edema, recover quickly when planted outdoors or when better greenhouse conditions are provided.
Plants plunged in wet material that steams can be badly damaged when moisture gathers on the underside of leaves. This moisture inhibits transpiration and promotes fugus growth, and this condition is most common when severe cold causes heating pipes to remain "on" for long periods. Most growers find that dry benches, either bare or with pea-gravel, are best for geraniums.
Ivy-leaf geraniums are quite prone to Edema and are most often affected when the baskets are hung high int he house where air is warmest, but where the foliage will be cooled by air entering the ventilators. These baskets are often watered by spraying, which only adds to the damage; watered with a copper tube, there will be less damage.
When watering in hot weather one is inclined to over water. Be careful because excessive dampness combined with high soil temperatures encourages fungus