Plant Of The Month
Geranium
Geraniums are one of the most popular decorative plants for both indoor and outdoor use. We have been growing geraniums for over 50 years, even before opening our store 33 years ago. Zonal geraniums are members of the genus 'Pelargonium.' They are primarily used for containers and for bedding during the spring, summer and fall. They are not winter hardy in our area, but some gardeners “take them in” in October to cary them over to the next season.
We choose the varieties we offer for color, growing habit, and perhaps most importantly, for heat tolerance. Some geraniums are better at with standing our summer heat and humidity than others. Those that quit blooming during the hottest months are said to “heat stall”. We only offer varieties that pass the test for this.
Zonal Geraniums usually have distinct leaf markings. This category includes selections with tri-colored or silver leaves, leaves with bands or zones of red or white and deeply pleated or frilly foliage. Flower colors range from deep burgundy to red and pink to purple, lavender, salmon and white, and they may be single or double petaled .
Our geraniums are propagated vegetatively. We find that “seed geraniums” (sold as small bedding plants) are inferior, as the blooms are usually “single”, and shatter easily. The plants don’t branch as well, and require regular pinching to stay neat.
Little care is necessary for a successful geranium planting, but a few things are important.
If planting in the ground, choose a spot that gets at least 6 hours of sunlight a day. Too much shade will inhibit blooming. Prepare the soil by loosening and adding a fair amount of organic matter. We recommend Mushroom Compost, but household compost, well decomposed is fine. Try to maintain even moisture and good drainage. The addition of organic matter will help to accomplish this. Feed regularly with a balanced fertilizer intended for blooming outdoor plants. Excessive nitrogen levels will cause the plant to become “vegetative”, which means it has excessive foliar growth and diminished bud set, i.e. beautiful plants with no color.
As blossoms mature, remove them by following the stem to the plant and snapping off stem and all. Removing faded blossoms will keep the plants attractive as falling petals can become a host for fungus in humid or damp weather. Avoid watering the blooms and foliage, as this can cause spotting, and shorten blossom life. A soaker hose, or drip irrigation system is beneficial. Water when soil is nearly dry, and then soak thoroughly.
When planting in containers, hanging baskets, or window boxes, use a sterile peat moss based potting mix, (we use ProMix). Avoid mixes containing bark, as these tend to steal nitrogen from the plants as the bark decomposes. Use pots at least 14” in diameter, and at least 8” deep. Pots should have drainage holes. Larger pots help in maintaining even moisture, even if more plants are used in the same pot. Place pots in a sunny area, and feel free to combine with other plants. Vinca vine is an old standard, but we offer many other companion plants suitable for this.
Geranium plants used outdoors are often overwintered indoors. However, it is often easier to buy new plants each spring. There are three basic methods of overwintering geraniums: dry (soil-less) storage, potted or cuttings. To overwinter your favorites using dry storage, carefully dig whole plants before frost, tie them in bundles, shake off the soil and hang them by the root ends in a cool basement or moist area for the winter. Storage temperature should be between 35 and 45°F, and the humidity should be 80 percent or higher. If plants dry out too much, occasionally take them down and soak the roots in water overnight. The plants can be cut back to about one-third of their original height and planted outdoors in May, or potted indoors in late winter. Plants to be overwintered in containers should be dug in the fall before the first frost, taking as much of the root system as possible. Use a container large enough to accommodate the root system, cut back to a height of 6 inches, place in a sunny window and water and fertilize as needed to promote healthy growth and encourage blooms.
Propagation
Geraniums can also be overwintered by taking cuttings from outdoor plants during late summer or early fall, before the first killing frost. This is one method of vegetative propagation, necessary to maintain the distinct markings, habit or shape and scent of many geraniums. Some geranium selections do not propagate easily from cuttings; these types are best purchased as new plants each year.
To propagate geraniums from cuttings, first select containers 3 to 4 inches deep and fill them with moist (not overly wet) planting medium. Satisfactory rooting media include coarse sand, perlite, vermiculite or a mixture of these. Sterile commercial mixes (such as ProMix) is also good. Cut off shoot tips 3 inches in length and remove the leaves on the lower part of the stem. The use of a rooting hormone is recommended to stimulate the rooting process. Dip the bottom 1/2 inch of each cutting in the rooting medium. Insert the cuttings to a depth of 1-1/4 inches to 1-1/2 inches. Water to settle the medium around the cuttings.
Avoid crowding the cuttings so there will be some air movement to help prevent disease. Cover the container with a plastic bag. This helps prevent excessive moisture loss, decreases wilting and increases rooting potential. Place the container in a warm location that receives bright, but indirect sun. Avoid excessive heat buildup in the bag by occasionally opening the top.
Check the moistness of the rooting medium every week. If properly chosen and prepared, it will usually stay fairly moist for several weeks before additional water is needed.
To determine when the cuttings have rooted, gently tug on the stem. If it resists being pulled from the rooting medium, roots have probably developed to a length of 1/2 inch to 1 inch, and the cuttings can be planted in small individual containers. Fill these containers with growing mix, and pot the cuttings at the same depth as the original rooting medium. Gradually move the plants into more direct light and continue to water. Fertilization will not be needed until the cuttings show new top growth.Visit us today to see our collection, and take one home. These make great plants for beginners as they are very forgiving and require little attention in exchange for so much color.