Q. WHY AREN'T MY GERANIUMS BLOOMING AS MUCH?
A. The two most common reasons for geraniums not blooming prolifically are too little light or too much fertilizer. Geraniums are a sun loving plant that need 4-6 hours of full sun a day, or perhaps longer in somewhat filtered light. South and west exposures are usually best. In too little sun, the plant will often grow, but will tend to grow a little bit taller or leggier, as it reaches for the light and it definitely will not bloom as much. The number of flowers is very much related to the amount of sun that the plant gets.
As far as fertilizing goes, if geraniums, like most annuals, get too much, you will get large, lush green plants and not as many blooms because the plant will be in more of a vegetative mode. In containers, if you feed your geraniums, every 3 to 5 weeks, you will be just fine. Use any of the water soluble fertilizers available, and just get a balanced solution (10-10-10 or 20-20-20). In the ground, your geraniums will need to be fed even less frequently; every 4 to 6 weeks should be sufficient. If you are going to make a mistake fertilizing, you are much better off to under feed than over feed.
Q. ARE THERE ANY GERANIUMS THAT GROW IN THE SHADE?
A. The simple answer to this is no, but there are some that will fare a little better in a less sunny spot. Typically, some of the Fancy Leaf varieties that have lighter colored foliage or foliage with white on it will tolerate a little less light, but will not thrive in deep shade and if they do live, they will not bloom a whole lot.
Q. DO I NEED TO CHANGE ALL OF THE DIRT IN MY POTS EVERY YEAR?
A. This will somewhat depend on the size of your pots, but if you can change the soil, that is the best. In larger planters, where that is more difficult, change at least half, to 'freshen' it up. When choosing a soil, make sure you get one that actually has some soil in it. There are many mixes that are commercially available that are soil-less mixes and although a good base, you do need to add some top soil or black dirt to them to make a little 'heavier' mix, that will hold a little more water. This is especially important in smaller pots and containers, because they will dry out so fast during the summer. The soil-less mixes are often easy to identify in the stores, because they are so light in weight. Any good potting soil will do, or mix some potting soil with one of the soil-less mixes for the best performance in your pots and planers.
Q. DO I NEED TO TAKE THE DEAD FLOWERS OFF OF MY GERANIUMS?
A. You do not absolutely have to, but it is definitely better if you do. We call it dead heading, here at the greenhouse, and you should do it after the blooms are spent and will begin to deteriorate at the top, where they also begin their blooming. Just gently snap the stem that holds the flower at the place where it joins the plant. It will come off quite easily and doing this will just encourage the other buds to open up a little sooner.
Q. WHAT IS THE DIFFERENCE BETWEEN SEED AND CUTTING GERANIUMS?
A. We always start our answer to this one by saying that all of the geraniums that we grow are cutting, or vegetative geraniums. The difference is the way in which they are produced or propagated. Seed geraniums are produced from a seed and cutting geraniums are produced by a cutting. I know that that may sound rather obvious, but the differences in performance are probably what is most important to the gardener. Cutting geraniums are typically larger in both plant and blossom size, while seed geraniums are more compact, with smaller, single blooms. There are certainly uses for both and gardeners should just know which type they are purchasing. Seed geraniums are often seen in larger, mass plantings, where a lower, very even height may be necessary or they are sometimes used in smaller containers, where they won't greatly overgrow the pot in the course of a season. Cutting geraniums are larger growing plants, with the larger blossom heads, that will fill out larger containers and hold their own with some of the more vigorous plants you may combine them with, such as the helichrysum 'Licorice Plant.'
Q. HOW CAN I KEEP MY GERANIUMS OVER THE WINTER?
A. This is a very often asked question, with a few different answers. We certainly have many of our customers who have methods that they have been using for years and have been passed down through families and the first rule of gardening applies: If it works, keep doing it. We have heard of things from shaking the soil from the plants and putting them upside down in brown paper bags in the attic, to placing them in an ice chest in the basement. Also suggested was in dry cleaning bags in the garage and in an old dish pan under the ping pong table.
As I said, if these work, that is great, but geraniums are an annual plant. And, as such, geraniums have no dormant season, so people are not putting them to sleep for the winter, they are pushing them to the edge of death and then yanking them back in the Spring. All of these things are a testament to how tough geraniums actually are, but they are an annual, not a perennial, so they do not die back and begin new growth each year, they continue growing from the same plant structure. So, gardeners will see that after saving them for a few years, they will begin to lose vigor, and start having smaller leaves and smaller, less frequent blooms.
The best thing that you can do, if you would like to save them, is to take a few cuttings and generate, new, fresh plants in the fall, that you can grow indoors over the winter and take back out in the Spring. That is basically what we do, here in the greenhouse, starting with new plants from cuttings each year in the late summer, for the next year. But, if that doesn't work out, just try bring plants indoors and keeping them growing.
You will need a bright spot, ideally a south or west window, and just cut the plant back by about 1/3 to 1/2 and bring it inside. Just like in the summer, you will want to water your geranium sparingly and with less plant and shorter days and less light, that might end up being every week or ten days. Even so, you may get a little spindly growth, as the plant reaches for the light, but do not worry about this. Just let the plant grow until the first or second week of March and then cut it back again, to have a bushier plant when it is ready to go back outside. And speaking of outside, get them out as early as possible, even if you have to protect them at night.
Give one or more of these methods a try; it will be a good gardening experiment, at the very least and what do you have to lose?
Q. WHAT ARE THE BROWNISH, RAISED BUMPS ON THE BACK OF MY IVY GERANIUM LEAVES?
A. This is a physiological condition that is call oedema (uh-DEEM-a) and is caused by cells in the leaves that burst because the plant takes up too much moisture without transpiring. Because ivy geraniums have a waxy texture, it is common to them and not to regular garden geraniums, that have a thinner leaf that is able to transpire. It is caused by a combination of humidity in the air and dampness from the soil and just more liquid than the cells can hold.
Gardeners will often think that it is caused by an insect, but it is not. It can happen once or twice and you might not even know, because it will only affect the underside of the leaves, but in extreme cases, where it is happening repeatedly, the spots can penetrate through, to the surface of the leaf and eventually destroy it. It is most common during cloudy damp weather. The best thing that you can do to combat it, is to water early in the day, so the plant has a chance to dry out during the day and grow your baskets without saucers, so they don't sit in water. Another thing you can do is buy more oedema resistant varieties that are less susceptible. Some of the best of these are some of the "Guillou" varieties that have been bred by the Guillou brothers and they say so on the tags.